Dr Dray Confirms UVA Penetration Triggers Tanning Through Sunscreen

Dr Dray

Because no topical sunscreen blocks 100% of ultraviolet radiation, penetrating UVA rays inevitably oxidize pre-existing melanin and induce delayed pigment synthesis even with diligent application.

AI-assisted summary of Can You Still Tan While Wearing Sunscreen? | Dermatologist Q&A — original source. Check the original for full context.

Source published: 2026-09-26

Key ideas

Tanning remains common even with consistent sunscreen use because no topical formula blocks 100% of UVA rays, which oxidizes existing melanin and triggers delayed melanogenesis. (10:52)
The belief that humectants like hyaluronic acid and glycerin dehydrate skin in arid environments is an outdated myth; properly formulated products do not wick endogenous water out of tissue. (4:54)
Sunscreen should be maintained during skin barrier repair because UV radiation oxidizes essential barrier lipids, while emollient sunscreen bases actively reduce transepidermal water loss. (2:24)
Burst capillaries around the eyes from violent coughing or vomiting represent Valsalva purpura, a pressure-induced extravasation of blood that typically resolves on its own within three weeks. (8:58)

Detailed notes

## Background Published on YouTube on September 26, 2026, by dermatologist Dr. Dray, this Q&A video tackles viewer questions regarding tanning through sunscreen, skin barrier repair, micellar water safety, and humectants in dry climates. According to the show notes, Dr. Dray provides evidence-based dermatology explanations covering hemosiderin staining, vascular redness, Valsalva purpura, topical zinc, and emerging research on topical metformin.

## TL;DR Dr. Dray debunks several pervasive skincare myths, explaining that compression socks do not cause lower-leg hemosiderin staining and dismissing internet claims that micellar water causes cancer. She emphasizes continuing sunscreen use during skin barrier repair to protect healing lipids and clarifies why humectants like glycerin and hyaluronic acid do not suck moisture out of the skin in arid environments. Additionally, she explains that violent coughing can rupture facial capillaries into Valsalva purpura, confirms that tanning through sunscreen is a genuine biological response to penetrating UVA rays, and reviews the formulation nuances of zinc alongside early research on topical metformin.

## Atmosphere & style The video maintains Dr. Dray's signature pragmatic, direct, and conversational clinical style, seamlessly blending rigorous dermatologic science with dry humor. She delivers reassuring reality checks against sensationalist online fearmongering, displaying visible empathy for patients dealing with disruptive symptoms like chronic coughing. Her willingness to transparently admit past residency misconceptions about humectants fosters an open, unpretentious dialogue that champions collaboration between medical dermatologists and cosmetic chemists.

## Bulletin - [10:52](https://www.youtube.com/watch?v=0ugi_-IfatE&t=652s) Tanning remains common even with consistent sunscreen use because no topical formula blocks 100% of UVA rays, which oxidizes existing melanin and triggers delayed melanogenesis. - [04:54](https://www.youtube.com/watch?v=0ugi_-IfatE&t=294s) The belief that humectants like hyaluronic acid and glycerin dehydrate skin in arid environments is an outdated myth; properly formulated products do not wick endogenous water out of tissue. - [02:24](https://www.youtube.com/watch?v=0ugi_-IfatE&t=144s) Sunscreen should be maintained during skin barrier repair because UV radiation oxidizes essential barrier lipids, while emollient sunscreen bases actively reduce transepidermal water loss. - [08:58](https://www.youtube.com/watch?v=0ugi_-IfatE&t=538s) Burst capillaries around the eyes from violent coughing or vomiting represent Valsalva purpura, a pressure-induced extravasation of blood that typically resolves on its own within three weeks.

## Key takeaways - [00:00](https://www.youtube.com/watch?v=0ugi_-IfatE&t=0s) Brownish discoloration on the lower legs associated with compression stockings is hemosiderin staining from chronic venous stasis and capillary leakage rather than melanin hyperpigmentation caused by the socks. - [01:43](https://www.youtube.com/watch?v=0ugi_-IfatE&t=103s) Claims linking micellar water to cancer lack scientific basis; consumers should focus cancer prevention on established risks such as UV radiation, smoking, alcohol consumption, and metabolic dysfunction. - [02:24](https://www.youtube.com/watch?v=0ugi_-IfatE&t=144s) Stopping sunscreen while repairing a compromised skin barrier is counterproductive, as ultraviolet radiation actively degrades stratum corneum lipids and impairs tissue recovery. - [03:04](https://www.youtube.com/watch?v=0ugi_-IfatE&t=184s) While micellar water effectively dissolves cosmetics as a first cleanse, leaving it on the skin risks contact irritation from lingering surfactants and preservatives, making rinsing advisable. - [04:08](https://www.youtube.com/watch?v=0ugi_-IfatE&t=248s) Fixed, dilated facial vessels (telangiectasias) require targeted vascular lasers for structural destruction, whereas diffuse redness can be temporarily mitigated with topical vasoconstrictors or tranexamic acid. - [04:54](https://www.youtube.com/watch?v=0ugi_-IfatE&t=294s) Modern cosmetic formulation science disproves the idea that glycerin and hyaluronic acid pull water out of the skin in dry climates; rapid evaporation is driven by pooling free surface water rather than formulated humectants. - [04:54](https://www.youtube.com/watch?v=0ugi_-IfatE&t=294s) Dermatology training traditionally emphasizes medical pathology and surgery over cosmetic chemistry, creating educational blind spots that benefit from cross-disciplinary dialogue with cosmetic chemists. - [08:58](https://www.youtube.com/watch?v=0ugi_-IfatE&t=538s) Valsalva purpura occurs when severe physical strain, such as intense coughing fits or vomiting, temporarily elevates intravascular pressure and ruptures delicate facial capillaries. - [08:58](https://www.youtube.com/watch?v=0ugi_-IfatE&t=538s) Non-smoking individuals experiencing persistent, unexplained coughing should be evaluated for common contributing conditions like gastroesophageal reflux disease (GERD) and chronic postnasal drip. - [10:52](https://www.youtube.com/watch?v=0ugi_-IfatE&t=652s) Tanning operates in two phases: immediate pigment darkening through UVA-induced melanin oxidation and delayed tanning through new melanin production, both of which can occur despite rigorous sunscreen application. - [12:34](https://www.youtube.com/watch?v=0ugi_-IfatE&t=754s) Topical zinc serves as an effective soothing protectant, but simply mixing zinc oxide powder into moisturizers fails to provide functional broad-spectrum sun protection due to particle clumping and uneven film coverage. - [12:34](https://www.youtube.com/watch?v=0ugi_-IfatE&t=754s) Topical metformin is being investigated for acne, hair loss, hyperpigmentation, and tissue regeneration, but clinical evidence remains in early stages and lacks definitive human trial verification.

## Detailed walkthrough ### [00:00](https://www.youtube.com/watch?v=0ugi_-IfatE&t=0s) Hemosiderin Staining and Compression Stockings

Dr. Dray kicks off the weekend Q&A by addressing a follow-up inquiry regarding a previous video about dark spots on the lower legs following compression stocking use. She had previously noted that these brownish discolorations are often not standard melanin hyperpigmentation, but rather hemosiderin staining. Hemosiderin forms when red blood cells escape from capillaries into surrounding dermal tissue and break down, leaving behind an iron pigment that Dr. Dray colloquially describes as "basically rust in the skin" that produces a distinct speckled brown appearance. A viewer asked why a compression sock would cause this to happen in the first place, finding the association counterintuitive.

Dr. Dray clarifies that while the mechanical friction and sheer physical difficulty of donning tight, medically prescribed compression stockings can provoke irritation and rubbing, the stockings themselves are rarely the primary culprit. Instead, the true cause is the underlying condition they are prescribed to manage: lower extremity venous stasis, fluid pooling, and lymphedema. When venous insufficiency causes blood and interstitial fluid to pool in the lower extremities, localized inflammation rises and red blood cells leak out into the tissue. This process frequently manifests as stasis dermatitis, where hemosiderin staining is a classic clinical finding.

```mermaid flowchart TD accTitle: Pathogenesis of Hemosiderin Staining in the Lower Leg accDescr: Flowchart illustrating how venous stasis leads to red blood cell leakage and hemosiderin staining in the skin.

subgraph VenousPathology["Underlying Venous Insufficiency"] A["Venous Stasis & Fluid Pooling"] --> B["Elevated Hydrostatic Pressure"] B --> C["Capillary Leakage & Inflammation"] end

subgraph Pigmentation["Tissue Deposition"] C --> D["Extravasation of Red Blood Cells"] D --> E["Breakdown of Hemoglobin"] E --> F["Hemosiderin Deposition ('Skin Rust')"] end

G["Tight Compression Stockings"] -.->|"Frictional irritation upon donning"| C ```

- Hemosiderin deposits result from extravasated red blood cells breaking down in interstitial tissue, creating a mottled brown "rust" stain rather than melanin-based post-inflammatory hyperpigmentation. - Medical-grade compression stockings require significant force and friction to put on, which may cause superficial irritation, but the primary cause of pigment deposition remains chronic venous hypertension and stasis dermatitis.

[01:43](https://www.youtube.com/watch?v=0ugi_-IfatE&t=103s) Debunking the Myth That Micellar Water Causes Cancer

Responding to a viewer who asked whether micellar water can cause cancer, Dr. Dray dismisses the claim as completely baseless internet sensationalism. She remarks on how easily alarmist narratives spread online, joking that someone on the internet will claim virtually anything causes cancer: "Somebody on the internet's going to be like, you're wearing a purple shirt, didn't you know that that [causes] cancer? It's like, did you know that if you live long enough the chances that you get cancer are quite great?"

She urges consumers to filter out arbitrary online hysteria and focus on exposures that have robust, reproducible, and epidemiologically proven links to carcinogenesis. Rather than worrying about personal care items like micellar water, people should prioritize mitigating clear, evidence-based risk factors supported by both mechanistic biological data and massive population studies: - Ultraviolet (UV) radiation exposure - Cigarette smoking and tobacco use - Alcohol consumption - Obesity and metabolic dysfunction

[02:24](https://www.youtube.com/watch?v=0ugi_-IfatE&t=144s) Sunscreen Use During Skin Barrier Repair

A viewer asks whether one should stop using sunscreen while trying to repair a damaged skin barrier. Dr. Dray advises against discontinuing sunscreen, with the sole exception being if a person is experiencing a genuine allergic contact dermatitis or direct stinging irritation from a specific formulation—in which case they should swap it for a gentler alternative rather than abandoning photoprotection entirely.

Sunscreen plays an active, dual-purpose role in facilitating skin barrier recovery: - **Moisturization and TEWL Reduction:** Most modern sunscreen lotions and creams are formulated within an emollient moisturizing base. Applying them creates an artificial barrier layer that reduces transepidermal water loss (TEWL) and helps replenish cutaneous hydration while the stratum corneum recovers. - **UV Shielding of Skin Lipids:** Ultraviolet radiation directly oxidizes and damages the endogenous intercellular lipids (ceramides, cholesterol, and fatty acids) essential to barrier integrity. UV exposure actively impairs barrier repair kinetics and prolongs inflammation, making continued photoprotection indispensable for tissue healing.

[03:04](https://www.youtube.com/watch?v=0ugi_-IfatE&t=184s) Micellar Water as a First Cleanse vs. Cleansing Oils

Addressing whether micellar water can substitute for a cleansing oil as the first step in a double-cleansing regimen, Dr. Dray acknowledges that many individuals use it this way. While she personally does not tolerate micellar water well and prefers traditional cleansing oils, she notes that micellar water is chemically capable of breaking up long-wearing makeup and cosmetic films.

Although micellar solutions were engineered in France as no-rinse cleansers—making them handy in pinches, such as camping out in the woods—Dr. Dray aligns with general dermatologic consensus in recommending that they be rinsed off the face during daily routines. Leaving micellar solutions on the skin allows surfactant residues, dissolved cosmetic grime, and formulation preservatives to remain in direct contact with the stratum corneum, substantially increasing the risk of contact dermatitis or localized irritation. Using a gentle water-based cleanser afterward ensures the emulsified makeup and residual surfactants are thoroughly cleared away without disrupting the skin.

[04:08](https://www.youtube.com/watch?v=0ugi_-IfatE&t=248s) Managing Vascular Redness and Telangiectasias

When asked about the best non-laser treatments for persistent vascular redness and visible superficial veins, Dr. Dray distinguishes between distinct vascular morphologies: discrete, enlarged blood vessels versus diffuse background erythema.

For fixed, arborizing superficial vessels known as telangiectasias—which commonly arise from chronic inflammation in rosacea or photoaging—topical skincare cannot eliminate the vessel walls. These dilated structural vessels necessitate procedural intervention, specifically vascular lasers such as pulsed dye lasers (PDL) or potassium titanyl phosphate (KTP) lasers, to achieve selective photothermolysis and vessel collapse.

For broad, diffuse vascular facial redness, post-inflammatory erythema (PIE), and the persistent flushing background seen in rosacea, Dr. Dray highlights several medical and topical avenues: - **Topical Vasoconstrictors:** Prescription alpha-adrenergic receptor agonists, including topical brimonidine and topical oxymetazoline, induce direct smooth-muscle contraction in superficial cutaneous arterioles, delivering significant temporary blanching of background redness. - **Topical Tranexamic Acid:** Emerging preliminary clinical data suggests topical tranexamic acid may help quell persistent erythema and vascular hyperactivity, though the evidence remains early compared to established prescription vasoconstrictors and vascular lasers.

[04:54](https://www.youtube.com/watch?v=0ugi_-IfatE&t=294s) The Humectant Myth in Dry Climates and the Education Gap in Dermatology

Dr. Dray takes on the persistent skincare myth that humectants like hyaluronic acid and glycerin are harmful to skin or hair in hot, arid climates like Arizona because they supposedly "pull moisture out of your skin" into bone-dry air. She openly admits that she was taught this exact concept during her dermatology residency and that older videos from a decade ago on her channel likely repeat the claim, but emphasizes that modern formulation science has soundly debunked it. Humectants in formulated skincare products do not wick endogenous water out of viable tissue into the environment.

True evaporative water loss occurs when free water sits on the skin surface and rapidly evaporates—such as lingering in a wet bathing suit (where water exposure, evaporative cooling, and fabric friction combine to compromise the barrier) or stepping out of a long, hot shower where thermal energy accelerates surface evaporation compared to a cold shower. Humectant molecules bound inside an emulsion do not behave like pooling surface water.

This misconception leads Dr. Dray to discuss the training landscape within dermatology. Historically, dermatology residency curricula focused on cutaneous pathology, procedural surgery, and diagnosing complex diseases (such as lichen planopilaris), dedicating virtually no curriculum time to cosmetic chemistry, vehicle formulation, or multi-step consumer routines:

| Domain | Dermatologists | Cosmetic Chemists | |:--- |:--- |:--- | | **Primary Scope of Practice** | Diagnosing and medically/surgically treating cutaneous diseases, inflammatory dermatoses, skin cancers, and scalp disorders (e.g., lichen planopilaris). | Engineering stable formulations, vehicle performance, surfactant dynamics, pH balancing, and ingredient interactions with the hair shaft and skin surface. | | **Traditional Skincare Role** | Advising on basic hygiene habits, gentle cleansers for sensitive skin/eczema, basic emollients, and contact allergy avoidance. | Designing emulsification systems, optimizing delivery mechanisms, and understanding the physical chemistry of raw ingredients. | | **Educational Blind Spot** | Often receive little to no formal training in finished product formulation, leading some practitioners to perpetuate outdated product myths. | Lack clinical medical training to diagnose disease, evaluate tissue pathology, or prescribe medical treatments. |

Dr. Dray laments that some dermatologists remain stubborn or dismissive when corrected by cosmetic chemists regarding formulation science. She argues that social media frequently creates a false adversarial dynamic pitting doctors against chemists. Instead, she advocates for active interdisciplinary collaboration, mutual humility, and an openness to retract outdated advice as cosmetic science evolves.

[08:58](https://www.youtube.com/watch?v=0ugi_-IfatE&t=538s) Burst Blood Vessels Under the Eyes and Valsalva Purpura

A viewer asks about developing burst blood vessels under their eyes whenever they come down with a bad cough or illness, wondering how to avoid it and how long the discoloration takes to completely fade. Dr. Dray explains that this phenomenon is called Valsalva purpura. In clinical practice, the Valsalva maneuver is a deliberate bearing-down action asked of patients to elicit specific physical exam findings—essentially forced exhalation against a closed airway, similar to straining during a difficult bowel movement. Outside the clinic, this happens during violent or forceful coughing, intense vomiting while sick, heavy weightlifting, or even blowing up party balloons with extreme effort.

When someone strains that hard, the sudden, temporary spike in localized intravascular pressure causes fragile facial capillaries to rupture and leak blood into surrounding tissue, resulting in purpura and petechiae. Dr. Dray notes that on the delicate skin of the face, this bruising typically resolves on its own within about three weeks. Preventing it theoretically means avoiding the Valsalva mechanism altogether, but when a person is violently coughing due to acute illness, that physical reflex is completely outside their control. Expressing deep empathy for individuals struggling with chronic or severe coughs, she remarks on how exhausting and socially embarrassing public coughing fits can be. She also advises viewers who suffer from an unexplained, persistent cough—and who do not smoke—to consult their physician, as common and treatable culprits include gastroesophageal reflux disease (GERD) and chronic postnasal drip.

- **Valsalva purpura mechanism:** High thoracic and cephalic pressure leads to capillary rupture and blood extravasation (bruising and petechiae). - **Typical resolution time:** Roughly three weeks on facial skin. - **Common triggers:** Violent coughing, vomiting, extreme weightlifting, intense balloon inflation, and severe straining. - **Underlying chronic cough causes to investigate:** Smoking, postnasal drip, and GERD.

---

[10:52](https://www.youtube.com/watch?v=0ugi_-IfatE&t=652s) Can You Tan Through Sunscreen?

Addressing a viewer question regarding whether an online creator is making excuses for slacking on sun protection by claiming she and her daughter tanned through sunscreen on vacation, Dr. Dray confirms that tanning straight through sunscreen is entirely genuine and very common. Sunscreen significantly lowers the total amount of ultraviolet radiation that reaches the skin, but no sunscreen blocks 100% of UV rays, and UVA in particular still penetrates. This effect is especially pronounced in individuals with deeper, melanin-rich skin tones.

```mermaid flowchart TD accTitle: The Two Phases of Tanning Through Sunscreen accDescr: Diagram illustrating Immediate Pigment Darkening caused by UVA oxidation versus Delayed Tanning driven by new melanin synthesis.

subgraph Phase1["Phase 1: Immediate Pigment Darkening"] UVA["UVA Exposure\n(Penetrates Sunscreen)"] --> OX["Oxidation of Pre-existing Melanin"] OX --> IPD["Rapid, Visible Darkening\n(Temporary)"] end

subgraph Phase2["Phase 2: Delayed Tanning Response"] IPD --> UP["Upregulation of Melanogenesis\n(Days Later)"] UP --> DT["De novo Melanin Production\n(Long-lasting Tan)"] end ```

Dr. Dray outlines the biphasic biological nature of tanning: 1. **Immediate Pigment Darkening (IPD):** Rapid darkening occurs almost as soon as one steps into sunlight due to the direct oxidation of pre-existing melanin by UVA rays. Although temporary, it is intensely noticeable in deeper skin types. 2. **Delayed Tanning:** Within a few days, the skin upregulates actual melanin production (*de novo* melanogenesis), establishing a long-lasting, deeper pigment change.

Because sunscreen alone cannot halt all incoming UVA, the only foolproof method to block tanning entirely is absolute physical shielding—dense-weave fabrics, UPF-rated sun-protective clothing, and wide face shields. However, as Dr. Dray humorously observes, "most people are not going to be walking around the beach in a scuba suit completely covered up from head to toe." Vacationers often do the best they can, and getting color while consistently wearing sunscreen is an expected biological reaction rather than proof of negligence.

---

[12:34](https://www.youtube.com/watch?v=0ugi_-IfatE&t=754s) Topical Zinc Formulations and Topical Metformin Research

Dr. Dray tackles viewer inquiries regarding topical zinc and the emerging excitement around topical metformin. Discussing zinc first, she points out its proven track record as an anti-inflammatory, soothing agent and skin protectant, which is why it features prominently in barrier formulas like diaper rash ointments. However, she issues a strong caveat regarding its use as a mineral sunscreen filter: simply mixing zinc powder into a cream does not create a functional sunscreen. Formulating zinc oxide for UV protection is a complex cosmetic science; improper formulations leave microscopic gaps across the skin because zinc particles naturally clump together rather than forming a continuous, protective film. A white cast does not equate to effective broad-spectrum coverage.

Turning to topical metformin—which some recent review papers hype as a potential skin "cure-all"—Dr. Dray notes that it is currently being investigated for several dermatologic applications: - **Acne management:** Due to anti-inflammatory properties. - **Hair loss:** Investigated for follicular signaling and tissue regeneration. - **Hyperpigmentation:** Showing early promise via anti-melanogenic pathways that suppress pigment synthesis. - **Tissue regeneration and wound healing:** Exploring cellular renewal benefits.

Despite these promising early findings, Dr. Dray emphasizes that the literature remains strictly preliminary. With no definitive clinical proof established yet, she cautions viewers not to "jump on the bandwagon" prematurely before robust human trials validate its real-world efficacy and safety. She wraps up the video by thanking viewers for their questions, teasing part two of the Q&A for the following day, and reminding everyone to wear their daily sunscreen and subscribe.

## Notable quotes > [00:11](https://www.youtube.com/watch?v=0ugi_-IfatE&t=11s) basically rust in the skin — Dr. Dray

> [01:43](https://www.youtube.com/watch?v=0ugi_-IfatE&t=103s) Somebody on the internet's going to be like, you're wearing a purple shirt, didn't you know that that [causes] cancer? It's like, did you know that if you live long enough the chances that you get cancer are quite great? — Dr. Dray

> [03:04](https://www.youtube.com/watch?v=0ugi_-IfatE&t=184s) Leaving micellar solutions on the skin allows surfactant residues, dissolved cosmetic grime, and formulation preservatives to remain in direct contact with the stratum corneum, substantially increasing the risk of contact dermatitis or localized irritation. — Dr. Dray

> [04:54](https://www.youtube.com/watch?v=0ugi_-IfatE&t=294s) pull moisture out of your skin — Dr. Dray

> [08:58](https://www.youtube.com/watch?v=0ugi_-IfatE&t=538s) When someone strains that hard, the sudden, temporary spike in localized intravascular pressure causes fragile facial capillaries to rupture and leak blood into surrounding tissue, resulting in purpura and petechiae. — Dr. Dray

> [10:52](https://www.youtube.com/watch?v=0ugi_-IfatE&t=652s) Sunscreen significantly lowers the total amount of ultraviolet radiation that reaches the skin, but no sunscreen blocks 100% of UV rays, and UVA in particular still penetrates. — Dr. Dray

> [10:52](https://www.youtube.com/watch?v=0ugi_-IfatE&t=652s) most people are not going to be walking around the beach in a scuba suit completely covered up from head to toe. — Dr. Dray

> [12:34](https://www.youtube.com/watch?v=0ugi_-IfatE&t=754s) A white cast does not equate to effective broad-spectrum coverage. — Dr. Dray

> [12:34](https://www.youtube.com/watch?v=0ugi_-IfatE&t=754s) jump on the bandwagon — Dr. Dray

## Mentioned Dr. Dray, Amazon, Facebook, Instagram, Pinterest, TikTok, Twitter, YouTube, Brimonidine, Glycerin, Hyaluronic acid, Metformin, Oxymetazoline, Potassium titanyl phosphate (KTP) laser, Pulsed dye laser (PDL), Tranexamic acid, Zinc oxide

## Video description In this skincare Q&A, dermatologist Dr. Dray answers questions from viewers about tanning through sunscreen, skin barrier repair, micellar water, vascular redness, hyaluronic acid, glycerin, tanning through sunscreen, purpura, topical zinc, and topical metformin.

Dr. Dray discusses why hemosiderin can appear in the lower legs, whether micellar water can cause cancer, and whether sunscreen should be avoided when the skin barrier is damaged. She also explains whether micellar water can replace cleansing oil in a double cleanse and discusses treatment options for persistent facial redness and dilated blood vessels.

The video also addresses the common misconception that hyaluronic acid and glycerin are harmful in hot, dry climates, explaining why these humectants do not simply pull moisture out of the skin or hair.

Additional questions cover Valsalva purpura from forceful coughing or vomiting, tanning despite sunscreen, topical zinc, oral zinc for acne and hidradenitis suppurativa, and the emerging research on topical metformin.

Topics covered:

0:00 Intro 0:11 Why Did the Hemosiderin "Leak Out"? 1:43 Can Micellar Water Cause Cancer? 2:24 Should You Stop Sunscreen While Repairing Your Skin Barrier? 3:04 Can Micellar Water Replace Cleansing Oil? 4:08 Best Treatments for Vascular Redness 4:54 Is Hyaluronic Acid Bad in a Dry Climate? 8:58 Burst Blood Vessels Under the Eyes From Coughing 10:52 Can You Tan Through Sunscreen? 12:34 Topical Zinc & Topical Metformin 13:45 Outro

Dr. Dray provides evidence-based dermatology information while addressing common skincare myths and misconceptions. Individual treatment decisions should be discussed with a qualified healthcare professional, particularly for persistent skin changes, unexplained bruising or purpura, significant redness, hair loss, or other concerning symptoms.

#SkincareQ&A #Dermatologist #DrDray #Skincare #Sunscreen #SkinBarrier #MicellarWater #HyaluronicAcid #Glycerin #SkinRedness #Purpura #Metformin #Zinc

FTC: This video is not sponsored. Links are commissionable, meaning I may earn commission from purchases made through links.

💜Shop my Amazon store https://o.bttn.io/0BwiPWFIZLG 💜Follow me on liketoknowit https://www.liketoknow.it/drdrayzday 💜Social media Instagram @drdrayzday Pinterest https://www.pinterest.com/drdrayzday/ Facebook @DrDrayzDay Twitter: @drdrayzday Tiktok: @drdrayzday

Disclaimer: This video is not intended to provide diagnosis, treatment or medical advice. Content provided on this Youtube channel is for informational purposes only. Please consult with a physician or other healthcare professional regarding any medical or health related diagnosis or treatment options. Information on this Youtube channel should not be considered as a substitute for advice from a healthcare professional. The statements made about specific products throughout this video are not to diagnose, treat, cure or prevent disease.

[Source](https://www.youtube.com/watch?v=0ugi_-IfatE)

中文简报

Dr Dray证实UVA穿透会导致涂防晒后依然晒黑由于没有任何外用防晒霜能100%阻隔紫外线，穿透的UVA射线即使在坚持涂抹的情况下，也必然会氧化原有的黑色素并诱发迟发性色素合成。 Dr. Dray澄清了几个流传甚广的护肤误区，解释了压力袜并不会引起小腿含铁血黄素沉积，并驳斥了网络上关于卸妆水致癌的说法。她强调在皮肤屏障修复期间应继续使用防晒霜以保护愈合中的脂质，并阐明了为什么甘油和透明质酸等保湿剂在干燥环境中不会吸走皮肤深层的水分。此外，她解释了剧烈咳嗽可能会震破面部毛细血管形成瓦尔萨尔瓦紫癜（Valsalva purpura），证实了涂防晒后依然晒黑是由于UVA穿透所产生的真实生理反应，并回顾了锌成分的配方差异以及外用二甲双胍的早期研究进展。即使坚持使用防晒霜，晒黑的情况依然很常见，因为没有任何外用配方能阻隔100%的UVA射线，穿透的射线会氧化现有黑色素并触发迟发性黑色素生成。 (10:52) 认为透明质酸和甘油等保湿剂在干燥环境中会使皮肤脱水的观点是过时的误区；配方得当的产品并不会将组织内的内源性水分吸出。 (4:54) 在皮肤屏障修复期间应保持防晒，因为紫外线辐射会氧化关键的屏障脂质，而润肤型防晒基质能有效减少经表皮水分流失。 (2:24) 剧烈咳嗽或呕吐导致眼周毛细血管破裂属于瓦尔萨尔瓦紫癜（Valsalva purpura），这是一种压力引起的血液外渗，通常会在三周内自行消退。 (8:58)

Reading summary

Dermatologist Dr. Dray addresses common clinical and cosmetic skincare misconceptions, explaining that tanning through sunscreen is a standard biological reaction to penetrating UVA radiation rather than a sign of product failure. She emphasizes the need to distinguish structural vascular issues from diffuse redness, evaluate formulation chemistry over online alarmism, and recognize the distinct expertise of medical doctors and cosmetic chemists. Tanning Mechanisms and Photoprotection Realities (10:52) Dr. Dray confirms that individuals can easily tan while wearing sunscreen because no commercial formulation blocks 100% of ultraviolet radiation, and UVA rays continue to penetrate the skin. Tanning occurs in two distinct phases: Immediate Pigment Darkening (IPD), where UVA exposure rapidly oxidizes pre-existing melanin, and delayed tanning, where the skin synthesizes new melanin over several days. Because full broad-spectrum blockade is impossible with topical filters alone—particularly in deeper, melanin-rich skin tones—only complete physical shielding like UPF-rated clothing prevents tanning entirely. Developing pigment on vacation while using sunscreen is an expected physiological response rather than proof of improper application. Dr. Dray also advises against stopping sunscreen during skin barrier recovery unless a patient is experiencing true allergic contact dermatitis or stinging from a specific product. Sunscreens are typically formulated in emollient bases that curb transepidermal water loss (TEWL) and hydrate the stratum corneum. Furthermore, shielding recovering tissue from UV radiation prevents the oxidation of essential intercellular lipids—such as ceramides, cholesterol, and fatty acids—which are required for barrier repair. Underlying Mechanisms of Vascular Skin Changes (0:00) Addressing lower extremity discoloration, Dr. Dray explains that brownish spots associated with compression stockings are typically hemosiderin staining from venous stasis, fluid pooling, and stasis dermatitis rather than friction from the garment. High hydrostatic pressure causes red blood cells to extravasate into surrounding dermal tissue, where degraded hemoglobin deposits iron pigment that resembles rust. Similarly, facial petechiae and under-eye bruising often stem from Valsalva purpura—a sudden spike in thoracic and cephalic pressure triggered by severe coughing, vomiting, or heavy lifting that ruptures fragile capillaries. On the face, this bruising typically resolves on its own within roughly three weeks. For facial vascularity, treatment differs based on vessel morphology. Fixed, arborizing superficial blood vessels (telangiectasias) possess structural vessel walls that topical ingredients cannot eliminate, requiring vascular lasers like pulsed dye lasers (PDL) or potassium titanyl phosphate (KTP) lasers to induce selective photothermolysis. Conversely, diffuse erythema and rosacea flushing can be temporarily managed using topical prescription vasoconstrictors such as brimonidine or oxymetazoline, with preliminary evidence also exploring topical tranexamic acid. Debunking Skincare Myths and Curriculum Gaps (4:54) Dr. Dray dismisses internet claims that micellar water causes cancer as unfounded sensationalism, advising consumers to focus on well-documented carcinogens such as UV radiation, smoking, alcohol consumption, and metabolic dysfunction. While micellar water effectively breaks down long-wearing cosmetic formulas, she aligns with dermatologic consensus in recommending it be rinsed off with water or a second cleanser. Leaving surfactant residues and preservatives on the skin increases the risk of contact dermatitis and localized irritation. She also refutes the common myth that humectants like glycerin and hyaluronic acid pull water out of the skin in dry climates, clarifying that humectants bound within cosmetic emulsions do not mimic the rapid evaporation seen with free pooling water. Dr. Dray notes that this misconception persists because dermatology residency curricula traditionally concentrate on diagnosing severe diseases, procedural surgery, and cutaneous pathology, offering virtually no training in cosmetic chemistry or formulation design. She advocates for interdisciplinary collaboration between dermatologists and cosmetic chemists to retire outdated product guidance. Formulation Limits and Emerging Dermatologic Actives (12:34) While topical zinc possesses proven anti-inflammatory and barrier-protecting benefits, Dr. Dray cautions against attempting to formulate DIY sunscreens by mixing zinc powder into lotions. Formulating zinc oxide for sun protection is an exacting discipline; improper suspension causes zinc particles to clump together, leaving microscopic gaps across the skin and rendering the white film ineffective against UV radiation. Regarding topical metformin, which has received attention as a potential dermatologic treatment, Dr. Dray notes that early research is investigating its utility for acne, hair loss, wound regeneration, and hyperpigmentation via anti-melanogenic pathways. However, she stresses that the current scientific literature remains strictly preliminary, warning consumers not to adopt the ingredient before rigorous human clinical trials demonstrate safety and real-world efficacy. Dr. Dray emphasizes that consumers should rely on established photoprotective habits and peer-reviewed dermatology rather than unverified internet claims. She warns against prematurely adopting unvalidated active ingredients like topical metformin and recommends clinical medical evaluations for chronic coughs or structural vascular lesions.

Source quotes

[0:11] Dr. Dray: basically rust in the skin [1:43] Dr. Dray: Somebody on the internet's going to be like, you're wearing a purple shirt, didn't you know that that [causes] cancer? It's like, did you know that if you live long enough the chances that you get cancer are quite great? [3:04] Dr. Dray: Leaving micellar solutions on the skin allows surfactant residues, dissolved cosmetic grime, and formulation preservatives to remain in direct contact with the stratum corneum, substantially increasing the risk of contact dermatitis or localized irritation. [4:54] Dr. Dray: pull moisture out of your skin [8:58] Dr. Dray: When someone strains that hard, the sudden, temporary spike in localized intravascular pressure causes fragile facial capillaries to rupture and leak blood into surrounding tissue, resulting in purpura and petechiae. [10:52] Dr. Dray: Sunscreen significantly lowers the total amount of ultraviolet radiation that reaches the skin, but no sunscreen blocks 100% of UV rays, and UVA in particular still penetrates. [10:52] Dr. Dray: most people are not going to be walking around the beach in a scuba suit completely covered up from head to toe. [12:34] Dr. Dray: A white cast does not equate to effective broad-spectrum coverage. [12:34] Dr. Dray: jump on the bandwagon

Original transcript

[0:00] Hey guys, welcome back to the weekend [0:02] Q&A. Getting into part one. These are [0:04] all saved in the Q&A playlist, too, if [0:07] you want to go back and watch older [0:08] ones, but without further ado, let's get [0:10] into it. Why did the hemosiderin leak [0:13] out in the first place from the [0:14] compression socks she used? Okay, so [0:16] this was a question I got a few weeks [0:18] ago about what to do about dark spots on [0:20] the leg after wearing compression [0:22] stockings, and I had to said, you know, [0:24] there's a chance that it's not actually [0:26] hyperpigmentation like melanin, but [0:28] rather something known as hemosiderin, [0:30] which is when the blood leaks out into [0:32] the surrounding skin, and then as the [0:34] blood cells break down, you get this [0:36] kind of like speckled brown appearance. [0:38] It's hemos- it's basically rust in the [0:40] skin. And so now this person is like, [0:42] why would a compression stocking cause [0:44] that, which makes this sound [0:45] counterintuitive, but a few reasons. [0:47] Number one is it is possible that the [0:50] person, the individual who asked the [0:52] question originally, got enough [0:53] irritation from just the friction of the [0:56] compression stocking of putting them on, [0:58] because putting them on is like a lot of [1:01] rubbing. They're really hard to get on, [1:03] the medically prescribed ones. They're [1:05] super, super tight. But the main reason [1:08] is not the compression stocking, but [1:10] what the compression stocking is [1:13] generally aimed at treating, and that is [1:15] lower leg venous stasis. So, collection [1:18] of blood lymphedema in the lower legs, [1:21] lower leg swelling. As that fluid sits [1:23] there in the tissue, well, you get a lot [1:26] of inflammation, and the blood leaks [1:28] out, and it's not uncommon. It's very [1:30] common, with what's called stasis [1:32] dermatitis, for you to have hemosiderin [1:35] there because of that. It could have [1:36] been, yes, the compression stocking, but [1:38] it also can likely be what it is that [1:41] the compression stocking is meant to [1:43] treat. I've heard that micellar water [1:45] can cause cancer. Thoughts? That's [1:47] false. I mean, somebody on the [1:49] internet's going to claim that anything [1:50] causes cancer. Somebody on the [1:51] internet's going to be like, you're [1:53] wearing a purple shirt, didn't you know [1:54] that that cancer? It's like, did you [1:56] know that if you live long enough the [1:59] chances that you get cancer are quite [2:01] great?" Stick to avoiding things that [2:03] are actually evidence-based for causing [2:05] cancer and like true true true [2:07] causative. Like not only do we have [2:09] mechanistic data, but we have tons of [2:10] epidemiologic evidence. Ultraviolet [2:13] radiation, smoking, alcohol consumption, [2:16] obesity is associated with an increased [2:18] cancer risk as well for sure. But [2:22] micellar water, I mean, no. [2:24] Should we stop using sunscreen when [2:27] we're attempting to repair a damaged [2:28] skin barrier? Unless you are allergic to [2:31] something in a given sunscreen or it's [2:32] irritating your skin, in which case [2:34] choose another sunscreen, but [2:36] sunscreen's very helpful in aiding a [2:37] barrier restoration because A, it's a [2:40] moisturizer, so it's going to reduce [2:41] transepidermal water loss, kind of step [2:43] in there for your skin barrier allowing [2:45] it to get back on track as far as [2:47] improving the water content. And B, [2:49] ultraviolet radiation, it damages the [2:52] lipids in the skin that are intended to [2:54] protect you and and act as a barrier, so [2:56] it leads to barrier impairment itself. [2:59] And it also slows down the healing [3:00] process. So the UV protection piece of [3:02] things is is really important there. So [3:04] can micellar water effectively replace [3:06] cleansing oil as a first step in a [3:08] double cleanse? I guess that's how some [3:10] people are using it. Like I've said, I [3:12] don't get along well with micellar water [3:14] and so I don't typically experiment with [3:17] it. I know that it's a product that was [3:19] designed and is formulated in such a way [3:22] that it's meant to not be something you [3:24] technically have to wash off. I still [3:26] recommend washing it off because it can [3:29] potentially have preservatives left on [3:31] the skin and mixed with makeup residue [3:34] could be irritating. And there are [3:36] allergic reactions that happen to [3:37] micellar water, so it is kind of like [3:39] just the going recommendation amongst [3:41] dermatologists to wash them off. But [3:43] some people will be like, "You don't [3:45] actually need to wash these off, okay?" [3:46] So in other words, if you're like out in [3:48] the woods somewhere, it's a great way to [3:49] wash your face, right? But routinely [3:52] every day if you're going to use it to [3:53] remove makeup, I still suggest coming in [3:55] with a gentle cleanser afterwards. Cuz [3:57] the micellar water will help to break up [3:59] the makeup film, and then, you know, you [4:01] get a proper face washing in, okay? [4:03] There's not a lot of advanced research [4:05] behind this. And like I said, I don't [4:06] really use micellar waters myself. I use [4:08] the cleansing oil thing. What is the [4:09] best treatment beside laser for vascular [4:12] redness? I heard that nothing can make [4:14] your superficial veins go back to normal [4:16] after they've been triggered by [4:17] inflammation. So, the prominent dilated [4:20] blood vessels, the telangiectasias, [4:22] yeah, that's going to be laser, pulsed [4:24] dye laser, vascular laser, for sure. Or [4:26] KTP. But, persistent facial redness, [4:29] vascular facial redness, that's not like [4:32] a vessel, the enlarged vessel that you [4:33] can see, like what patients with rosacea [4:35] go on to develop. You know, they have [4:37] both. They have the telangiectasias, but [4:38] they also have persistent facial [4:40] redness. Or some patients have [4:41] post-inflammatory erythema. Topical [4:43] brimonidine or topical oxymetazoline. [4:46] Those are vasoconstrictors. They can [4:48] also help quite a bit. Some patients [4:50] have good success with topical [4:52] tranexamic acid, but the data on that is [4:54] a lot more preliminary. Is it true that [4:56] glycerin and hyaluronic acid are bad for [4:58] your hair or skin if you live in a hot, [5:00] dry climate like Arizona? I've heard it [5:02] pulls moisture from your skin since [5:03] there's no moisture in the environment. [5:05] I'm not sure if that's true. No, you [5:06] know, I was even taught this in [5:08] dermatology residency, and I'm sure if [5:10] you go back 10 years ago on my channel, [5:11] you'll find me say this somewhere in a [5:13] video somewhere, buried somewhere that I [5:15] can't even find to like delete or get [5:17] rid of because I've since learned that [5:19] no, that's absolutely not true. And that [5:22] this is a myth that hyaluronic acid, if [5:24] it you know, used in a dry climate or [5:26] without plenty of ample occlusives on [5:28] top, it's going to you know, lead to [5:30] more water loss out of the skin. Now, [5:32] where we do see that happening is like [5:34] if you have water on your skin, like if [5:37] if you get your skin wet, and you leave [5:38] that water on the skin, like if you hang [5:41] out in a wet bathing suit, for example, [5:42] you're wet, the bathing suit's wet, you [5:44] got a a of friction, that is a situation [5:46] where you will get a lot more skin [5:48] irritation and ultimately dryness. It [5:51] will pull out more. You will have more [5:53] evaporative water loss. Or if you take a [5:55] really long hot shower, as you step out [5:57] of a hot shower, you will have more [5:59] water coming out of your skin than if [6:01] you step out of a cold shower just [6:03] because of evaporation. But, hyaluronic [6:06] acid doesn't doesn't do that itself nor [6:09] do any other humectants. And that's [6:11] that's one of those myths. Remember what [6:13] I told you guys a couple of weeks ago in [6:14] this Q&A about how um we don't really [6:17] get as dermatologists as much skin care [6:20] education as people believe that we do [6:22] in residency. And a lot of what we are [6:24] taught, just like this happens with [6:26] aestheticians too and they'll admit it [6:28] to you, you know, that a lot of what you [6:29] end up getting taught and training with [6:32] regards to skin care is simply not [6:34] correct or, you know, it's been debunked [6:36] but it just gets perpetuated because no [6:38] one really up until a few years ago, you [6:40] know, with the pandemic. And now it's [6:42] become even more pressing that [6:43] dermatologists have their hands in on [6:45] skin care. But, back in the day like [6:47] skin care was just really not relevant [6:50] at all to the majority of dermatology [6:52] visits unless you were coming in with a [6:54] contact dermatitis to a skin care [6:56] product you had used. Yeah, it would [6:57] come up as far as like moisturizing, [7:00] gentle cleansing for, you know, [7:01] sensitive skin or eczema care, bathing [7:04] habits, acne skin care, wash your face [7:06] regularly because of removing skin Those [7:09] kind of things, a lot of what I [7:10] continued to talk about in my videos. [7:12] That's where it was relevant, not like [7:14] what's good serum for this. I was like, [7:16] "What? Huh?" Because the industry has [7:18] just blown up with claims and things [7:21] like that. And some ingredients do show [7:23] promise for things so, you know, it's [7:25] it's it's a more of an issue. People are [7:26] coming in with these multi-step skin [7:28] care routines. That was never a thing. [7:30] And so a lot of things have changed. I [7:32] am not seeing evidence though that a lot [7:35] of the messaging or training or [7:37] educational materials with regards to [7:39] skin care formulations has necessarily [7:42] undergone some renaissance in [7:43] dermatology training because I do still [7:46] find that a lot of dermatologists do [7:48] just repeat some of these things and [7:50] some of them are also very resistant or [7:52] stubborn about being corrected by you [7:55] know the cosmetic chemists who [7:56] specialize in this and it's really [7:58] technically not the area of expertise of [8:01] dermatologists because we're the [8:03] specialty with expertise in diagnosing [8:06] and managing skin diseases like in plano [8:08] pilaris you know you're [8:10] not going to get information from a [8:11] cosmetic chemist about that they know [8:13] nothing about that but they can tell you [8:14] about how a shampoo is going to remove [8:17] oil from your scalp and and that kind of [8:19] thing you know they know how product [8:21] formulation and chemistry and pH and [8:23] everything interact with the hair shaft [8:25] and way more than a dermatologist does [8:27] but a lot of times I see online that [8:29] people want to pit one against the other [8:31] when in reality it needs to be very [8:33] collaborative and ongoing conversations [8:35] because we all have our own like super [8:37] area of expertise but we rely on one [8:39] another to really give the audience the [8:41] best the best available evidence and [8:43] everything and we have to be willing to [8:44] admit when we don't know something and [8:46] when you know the information that we [8:48] may have been giving out was not [8:49] necessarily correct or has been updated [8:51] or you've learned new things since then [8:53] you need to correct you need to be [8:54] willing to say that otherwise it harms [8:56] the audience and they lose trust very [8:58] quickly whenever I have a really bad [9:00] cough or I'm sick I get burst blood [9:02] vessels under my eyes is there anything [9:03] that I can do to try and avoid this and [9:05] how long does it take for the [9:06] discoloration to completely fail to [9:08] completely fade so this is called [9:10] Valsalva purpura Valsalva is just a it's [9:12] a maneuver that we ask patients to do in [9:15] office for eliciting certain physical [9:17] exam findings it's like if you force [9:19] yourself to exhale but you you bear down [9:21] and because you when you [9:23] like when you strain on the toilet I [9:26] don't know hopefully you don't have to [9:27] do that but for example forcible [9:29] coughing it can happen when you forcibly [9:31] vomit when you're sick or it also [9:34] happens in patients who lift weights [9:36] heavy weight lifting if you blow [9:38] balloons, you know, cuz you're [9:40] like that, okay? And what happens when [9:42] you do that is you get kind of this [9:43] temporary change in your blood pressure, [9:45] and it can cause temporary leak of the [9:48] capillaries, and you Yeah, you [9:50] absolutely can get purpura, which is [9:52] kind of like bruising, petechiae, blood [9:54] leaking out into the skin. On the face, [9:56] that typically is going to fade away in [9:57] about 3 weeks. I mean, I tell you don't [10:00] do Valsalva, and that's how to prevent [10:02] it, but when you're forcibly coughing [10:04] when you're sick, that's not really [10:05] something that you can control. So, [10:06] unfortunately, there's not really much [10:08] that you can do. Um, you know, try and [10:10] not get sick. [10:11] >> [laughter] [10:12] >> I hope you don't get sick this year. I [10:13] really hope you don't, or that you're [10:15] not sick currently. Don't want I mean, I [10:17] I feel so bad when people have chronic [10:19] coughs or anything because they are just [10:21] suffering so much, and you can hear it, [10:24] and and it's like and and then they get [10:26] embarrassed if they are coughing [10:27] forcibly in public. Uh, I just I feel so [10:30] terrible for people who have chronic [10:32] cough of any sort cuz it can become a [10:34] chronic thing, depending on You know, a [10:36] lot of smokers will have just a chronic [10:37] cough. You're specifically asking about [10:39] when you're sick and you're forcibly [10:40] coughing, but some people get a chronic [10:42] cough because of postnasal drip. Okay, [10:44] so if you do have a cough and you don't [10:45] smoke and you're like, "What the heck is [10:46] going on?" Talk to your doctor cuz you [10:48] could have GERD. It could be that, you [10:50] know, you could have GERD, or you could [10:51] have postnasal drip. A creator I just [10:53] started watching says that she got a tan [10:55] on vacation even though she claims she [10:57] used sunscreen. She said her daughter [10:59] tans through sunscreen as well. She said [11:01] that is due to her skin type. Is that a [11:02] bunch of BS? I think she slacks off the [11:05] sunscreen. She doesn't want to admit it. [11:06] Am I too cynical? You know, you can [11:08] absolutely commonly tan straight through [11:10] sunscreen because it doesn't block 100% [11:13] of UV. It will allow UVA to come [11:16] through. It, you know, it just lessens [11:17] the overall amount to, you know, a good [11:20] good amount, but not [11:21] 100%. For people who are [11:24] have a deeper skin tone, absolutely, [11:26] they will tan through sunscreen. And [11:28] tanning is this biphasic process where [11:30] you get immediate pigment darkening. you [11:32] get like really dark like very soon [11:35] being in the sun. That's because of the [11:36] oxidation of melanin in your skin from [11:38] the UVA. And then, you know, within a [11:40] couple of days your tanning response, [11:43] delayed tanning response actually kicks [11:45] in where you're upregulating pigment [11:46] production and you get a deeper skin [11:48] skin color that's, you know, [11:49] long-lasting. The immediate pigment [11:51] darkening is not permanent, but if you [11:53] have a really deep skin tone, we [11:54] probably know what I'm talking about. [11:56] Like you go outside and you're like, [11:57] "I'm immediately getting dark." That's [11:58] oxidation of existing pigment in the [12:01] skin. And that absolutely can happen [12:02] through sunscreen. The only way to [12:04] prevent that is to use like total [12:06] coverage [snorts] of the skin with [12:08] either a really dense weave fabric, UPF [12:11] clothing, um shields and things like [12:13] that. So, if someone goes on vacation, I [12:15] mean, let's be realistic, most people [12:17] are not going to be walking around the [12:18] beach in a scuba suit completely covered [12:20] up from head to toe. Going to get UV [12:23] unless you're, you know, that's why I [12:24] say rain in other sun protective [12:26] behaviors to really cut down the risk [12:28] like sun protective clothing, but you [12:30] know, people do the best they can and if [12:31] they said that they're using sunscreen, [12:33] you can tan through it absolutely. Zinc, [12:36] topical or what are your thoughts on [12:37] topical Metformin? From the review [12:39] papers, it seems to be a cure-all. Okay, [12:41] so topical zinc is anti-inflammatory, [12:44] soothing, and it really depends on the [12:46] overall formulation. So, it can also act [12:48] as a skin protectant. That's why it's in [12:49] diaper rash creams. It can also act as a [12:52] sunscreen agent. Although, that's got to [12:54] be formulated correctly. Just having [12:56] zinc in something does not a sunscreen [12:58] make cuz it's got to be the right kind [12:59] of zinc. It's got to be formulated the [13:01] right way so it effectively coats the [13:03] skin in a way to deliver that [13:05] protection. You can't just put zinc in a [13:07] cream, see it go on white, stay on [13:09] white, and that that's not sunscreen cuz [13:12] it leaves behind, you know, what you [13:14] can't see microscopically are all these [13:16] gaps where you're not actually where you [13:17] don't actually have the zinc cuz it [13:19] clumps together. So, there's that. Now, [13:21] as far as the topical Metformin, it is [13:23] being investigated for like acne, hair [13:26] loss, and hyperpigmentation, [13:28] anti-inflammatory effects, and some uh [13:31] you know, potential tissue regenerative [13:33] effects, anti-melanogenic, anti-pigment, [13:35] and showing some promise, but it's all [13:37] very preliminary at this point. Nothing [13:40] definitive, only time will tell as far [13:42] as that. I would not I wouldn't jump on [13:44] the bandwagon of that shoe prematurely. [13:46] All right, guys. Thank you so much for [13:49] all of your great questions. Come back [13:50] tomorrow for part two. I'll be answering [13:53] even more. But, if you enjoyed today's [13:54] video, give it a thumbs up, share it [13:56] with your friends, and as always, don't [13:57] forget sunscreen and subscribe. I'll [13:59] talk to you guys tomorrow. Bye. [14:21] >> [music]