TikTok Trend Watch with Joshua Zeichner, MD T ikTok is an endless source of skincare advice, both good, evidence-based advice from credentialed professionals and incredibly bad, unsound advice from inexperienced (but compelling) influencers. TIKTOK TREND: DIY MICRONEEDLING WHAT IT IS: TikTok users are trying do-it-your-self, at-home microneedling devices in the hopes of boosting collagen and smoothing fine lines and wrinkles. Here, Joshua Zeichner, MD, Associate Professor of Dermatology and Director of Cosmetic and Clinical Research in Dermatology at Mount Sinai Hospital in New York, NY, gives the real skinny on two trending skincare topics. TIKTOK TREND: BEEF TALLOW AS A MOISTURIZER WHAT IT IS: Many TikTok users are slathering beef tallow on their skin as a moisturizer. MD VERDICT: DON’T TRY THIS AT HOME “Microneedling in a dermatologist’s oce? Great treatment. DIY microneedling in your bathroom with a mystery derma roller from the internet? I am not a fan,” says Dr. Zeichner. “Professional microneedling is performed under sterile conditions with controlled needle depth. At home, you’re essentially poking holes in your skin and hoping for the best, which is how we end up seeing infections, scarring, and pigmentation issues in the oce later,” he says. People like the idea of a budget-friendly col-lagen boost, but the devices sold online drag across the skin and can create tears rather than clean micro-injuries, he explains. “Combine that with a lack of proper sterilization, and you’ve got the perfect recipe for irritation or even long-term damage.” Dd . JOSHUA ZEICHNER, MD, is the Director of Cosmetic and Clinical Research in Dermatology and an Associate Professor of Dermatology at The Mount Sinai Hospital in New York City. MD VERDICT: SAVE THE TALLOW FOR COOKING “Just because beef tallow is old-school doesn’t mean it’s good for your skin. Yes, it’s thick and occlusive, but it’s also made of saturated animal fats that weren’t created with healthy pores in mind,” says Dr. Zeichner. “If you’re acne-prone, this is basically rubbing a cheese-burger on your face.” Unlike modern moisturizers, tallow doesn’t replenish the skin’s actual barrier lipids in the right ratios, which is how you truly repair dry-ness or irritation. Instead, it just sits on top of the skin, trapping sweat and debris, and po-tentially provoking breakouts or irritation. Residents’ Corner To support residents' professional journeys, Neutrogena collaborated with West Islip, NY-based Dermatologist Kavita Mariwalla, MD, and Boards University to launch educational sessions and exclusive webinars designed to provide residents with the most current and comprehen-sive knowledge. This partnership ensures that residents have access to cutting-edge resources and tools for continuous learning. Visit Boards University to learn more. https://boardsuniversity.com Boards U Highlight December 2025 | S9
The Dermatology Digest Innovations in Pre-, Peri-, and Post- Procedure Skincare December 2025: S-9
