Beef Tallow: Rendered Fat, Not a Miracle Moisturizer
PA Buchi Neita opens the conversation with the trend that has, in PA Lisa Weiss's words, dominated the last year — beef tallow. Patients show up with jars they bought at farmers' markets and local farms, some having seen billboards touting it as "the new sunscreen." Social media promotes it as bioidentical to sebum with "ancestral" healing properties for eczema, acne, and nearly everything else.
Weiss reframes the glamorous marketing: beef tallow is rendered animal fat, primarily triglycerides (oleic, palmitic, and stearic acids) with a small amount of fat-soluble vitamins. It is occlusive, so it may help very dry or eczema-prone skin with transepidermal water loss—but that same occlusiveness makes it a poor choice for acne or sensitive skin, and at high concentrations it can disrupt the skin barrier.
Neita notes her research found no high-quality clinical trials on topical beef tallow and no head-to-head studies against the occlusives dermatology already uses. It does not replicate human sebum and lacks wax esters and squalene. Both point patients back to plain petrolatum—inexpensive, well-studied, and effective without the barrier issues. Neita reports seeing four recent cases tied to beef tallow: a rosacea flare, an acne flare, and two significant cases of periocular and perioral dermatitis. Weiss adds a counseling point worth using in the room: beef contains hormones, so patients may be rubbing exogenous beef hormones all over their skin.
Korean Skin Care and 'Glass Skin': Good Principles, Too Many Steps
The hosts are more sympathetic to Korean skin care. "Glass skin" refers to smooth, luminous, reflective skin, and the regimens emphasize hydration, gentle exfoliation, and true barrier support — the same priorities dermatology already champions. Weiss highlights the ingredients that carry real backing: humectants like glycerin and hyaluronic acid, niacinamide for barrier function and inflammation, and mild exfoliants to smooth the stratum corneum.
The catch is the routine itself, often seven to 10 steps. Weiss questions the cost, the unknown efficacy of individual ingredients, and the unknown interactions when so many products are layered. Neita adds a dose of realism: influencers achieving "glass skin" often have perfect lighting immediately after applying moisturizers, and it's normal to have visible pores and texture — the trend can set unrealistic expectations.
Weiss's biggest takeaway from the research: no randomized controlled trials compare Korean to Western skin care, and the real success may simply be that Korean skin care culture adopts daily sunscreen and photoprotection early, with less emphasis on tanning. Her advice, regardless of which product line a patient chooses, is to keep the routine simple and use the ingredients that perform best for that skin.
PDRN: The Trend With Actual Reparative Data
Neita admits she was excited about PDRN — polydeoxyribonucleotide, DNA fragments derived from salmon (popularly, salmon sperm) — used in both injectable and topical formulations and very popular in South Korean aesthetic clinics. Weiss explains the proposed mechanism: activation of adenosine A2A receptors, promoting tissue repair and angiogenesis.
Unlike the other trends, Weiss says substantial preclinical evidence supports wound healing and tissue regeneration, with emerging but limited clinical trial data for aesthetic applications such as post-procedure repair and reduced healing time, apparently without significant side effects. Her caution: she would stick to topical formulations for now and avoid injecting it until more data are available.
Social Media Education: The Trend Both Hosts Love
The episode’s favorite trend is patients arriving informed. Neita and Weiss both report younger patients — even 7- to 13-year-olds — asking about topical retinoids, azelaic acid, niacinamide, alpha hydroxy acids, and the difference between mineral and chemical sunscreens. Weiss notes that dermatologists and Derm APPs becoming social media influencers are putting correct information out there, and both wish those voices reached the beef-tallow crowd.
The downside is overdoing it: patients layering 15 products and developing irritant dermatitis that's impossible to untangle. Both hosts advise a clean break — gentle cleanser and moisturizer — then slowly adding ingredients based on need. Weiss makes sunscreen her non-negotiable first step, telling patients she can't reverse sun damage faster than they create it, and recommends powder stick and brush formats for reapplication. Neita notes older patients, particularly women of color, often need more convincing that sunscreen matters even without burning — for hyperpigmentation and post-inflammatory pigmentation. Both praise the newer tinted mineral sunscreens, including affordable over-the-counter options, for matching skin tones without the white or purple cast.
Red Light Masks: Promising, But Proceed With Caution
Neither host owns a red light mask yet. Weiss, a melasma patient, has one sitting in her online cart but holds back because the research suggests red light can work against hyperpigmentation and melasma. Moderate clinical evidence supports skin rejuvenation—improvements in wrinkles, texture, and collagen synthesis—but efficacy depends on how the mask delivers light and how the skin absorbs it.
The hosts' shared frustration is their inability to recommend a specific product: no dose validation for wavelength or duration, limited data on mask shape and fit, and no assurance that more expensive means more effective—not all red light masks are created equal. Weiss also notes the American Academy of Dermatology does not support red light therapy at tanning salons. Both are waiting for stronger data, especially on hyperpigmentation, melasma, and post-inflammatory hyperpigmentation, before recommending them.
Weiss closes with her overarching message for patients: natural does not always mean better. Both hosts hope future trends move toward evidence-based, well-studied skin care.