GHK-Cu and peptides for skin aging: what the research says

What did @drspf actually say?

Board-certified dermatologist @drspf laid out a morning and evening skincare routine aimed at people in their 30s. The morning stack: gentle cleanser, vitamin C serum at "10 to 20%," a hydrating eye serum with hyaluronic acid and caffeine, and a moisturizer with SPF. For hyperpigmentation, she specifically called out tinted sunscreen with iron oxides to block visible light. Evening: salicylic acid cleanser for pores and body acne, a retinoid described as "the biggest step," and a moisturizer. Her tone was prescriptive, "this is not negotiable," but the advice stayed general enough to avoid recommending specific products or doses.

The routine is standard fare for a dermatologist-approved anti-aging protocol, and the framing was consumer-friendly without veering into exaggeration. She did not make extraordinary claims about reversing aging or curing anything, which is worth noting up front.

Does the science back this up?

Mostly, yes. The core ingredients she recommended, retinoids, vitamin C, and broad-spectrum SPF, have the deepest evidence base in photoaging research. The iron oxide call-out is a more advanced point that many creators get wrong, and she got it right.

Retinoids are the most studied topical anti-aging ingredient we have. Kligman et al. (1986, Journal of the American Academy of Dermatology) established tretinoin's effect on fine lines, and subsequent randomized trials have consistently supported topical retinoids for collagen remodeling. Vitamin C as L-ascorbic acid at concentrations between 10% and 20% has demonstrated efficacy in reducing melanin synthesis and oxidative stress, per Telang (2013, Indian Dermatology Online Journal). The caffeine and hyaluronic acid eye serum recommendation is softer, the evidence for caffeine on periorbital dark circles is plausible but limited to small trials. Draelos (2007, Journal of Cosmetic Dermatology) found modest improvement with caffeine-containing formulas, but effect sizes were modest. Hyaluronic acid for hydration is well-supported. The iron oxide tinted sunscreen advice is backed by Lyons et al. (2021, Journal of the American Academy of Dermatology), which showed iron oxides reduce visible light transmission and melasma recurrence meaningfully compared to chemical UV filters alone.

What did they get wrong (or right)?

She got more right than wrong, which is not always the case in dermatology TikTok. The retinoid recommendation was appropriately cautious, pea-sized amount, no specific prescription drug named, and she acknowledged budget-friendly options without being misleading about efficacy differences. The salicylic acid body cleanser recommendation for body acne is evidence-supported.

The eye serum section is where the advice gets a little wobbly. Saying "I struggle with bags under your eyes" and recommending a topical caffeine serum slightly oversells what the ingredient can do. Periorbital puffiness from fat pad herniation or fluid retention has limited response to topical caffeine. It may reduce temporary morning puffiness via vasoconstriction, but it does nothing for structural causes. A board-certified dermatologist probably knows this distinction, and the video would have been stronger if she had drawn it.

The vitamin C mnemonic, "think about orange juice, you drink it in the morning," is a memory aid about morning application timing, which is reasonable since vitamin C is photolabile and pairs well with daytime antioxidant protection. But the analogy could mislead viewers into thinking concentration or pH matching does not matter. Topical L-ascorbic acid stability depends heavily on formulation, not just timing.

What should you actually know?

The routine she described is legitimately evidence-based for most people in their 30s dealing with early photoaging and uneven skin tone. But layering all of these products simultaneously without skin-barrier tolerance is where people go wrong in practice.

Retinoids cause retinization, a period of dryness, peeling, and irritation, especially when someone is new to them. Starting with the lowest available concentration and applying over a moisturizer (the "sandwich method") reduces dropout rates, per Leyden et al. (2017, Journal of Drugs in Dermatology). Combining retinoids with salicylic acid on the same night, even in separate steps, can push irritation higher in sensitive skin types. The video did not address sequencing concerns at all.

Also worth knowing: not all retinoids perform equally. Over-the-counter retinol must be converted to retinoic acid by skin enzymes, making it less potent than prescription tretinoin. "Budget" retinol products are not equivalent substitutes if someone needs clinical strength. That is not a criticism of affordability, it is a formulation reality that a viewer deserting dermatologist visits for a TikTok routine should understand.