GHK-Cu and peptide anti-aging claims: what Korean skincare TikTok gets right and wrong

What did @yunique_kbeauty actually say?

A self-described Korean pharmacist rated several viral anti-aging products, assigning numerical scores to each. The creator flagged NAD concentration as legitimately relevant to anti-aging effects, praised NMN toner at "10,000 ppm" for skin glow and texture over time, gave high marks to a PDRN serum at "1,200 ppm of salmon DNA" for skin texture and hydration, and was skeptical of a collagen serum featuring "collasin and borufine" for lacking clinical data on anti-aging benefits. The bubble toner's seven-second activation texture was also noted as a positive feature. The framing throughout was product-review with pharmacist credibility implied, which matters because viewers may weight these claims differently than influencer opinions.

Does the science back this up?

On PDRN and NMN, the creator is largely on solid ground. PDRN has a genuine evidence base. NMN topicals are a more complicated story, and the "10,000 ppm" framing is mostly marketing math. The collagen skepticism is fair but underdeveloped.

PDRN (polydeoxyribonucleotide) has been studied in wound healing and skin regeneration contexts. A 2020 randomized controlled trial by Veronesi et al. published in Biomedicines found PDRN activated A2A adenosine receptors and supported tissue repair. Dermatology-specific work, including a 2022 study by Kim et al. in the Journal of Cosmetic Dermatology, showed improvements in skin hydration and elasticity with topical and injectable PDRN. The 1,200 ppm figure is within ranges used in studied formulations, though topical delivery depth is genuinely limited compared to injectable forms.

NMN topicals are where things get murky. NMN is a precursor to NAD+, and systemic NMN supplementation has shown promise in raising NAD+ levels (Yoshino et al., 2021, Science). But skin penetration of NMN at cosmetic concentrations is poorly studied. The "10,000 ppm" number sounds impressive but is unverified against clinical benchmarks for topical efficacy.

What did they get wrong (or right)?

The collagen skepticism was the creator's strongest call and also their least-developed one. They were right to question it. The biggest errors are in the NMN dosing framing and the implicit suggestion that ppm numbers equal clinical efficacy.

On collagen: oral and topical collagen peptide research has grown substantially. A meta-analysis by Bolke et al. (2019, Nutrients) found hydrolyzed collagen supplementation improved skin elasticity and hydration in randomized trials. Topical collagen is a different story because the molecules are largely too large to penetrate the skin barrier, so the creator's skepticism about "collasin" in a topical serum is arguably correct, even if their reasoning wasn't fully stated.

The bubble texture being observed in "seven seconds" is purely a sensory marketing feature. It has no known clinical correlation with ingredient efficacy. Presenting it as a positive data point is where the pharmacist framing slips into influencer framing. That deserves a flag.

"Borufine" appears to be a trademarked ingredient (a boron-based peptide-like compound). There is minimal independent peer-reviewed data on it. The creator's skepticism here is reasonable, though calling it out by name with a low score without explaining why would leave most viewers no better informed than before.

What should you actually know?

PPM numbers in skincare marketing are not standardized against clinical trial dosing, so "10,000 ppm" of NMN in a toner tells you almost nothing about whether it works. Topical bioavailability, vehicle formulation, and molecular size all matter more than the concentration on the label.

PDRN is one of the more legitimately researched ingredients in this category, with a growing body of peer-reviewed work, though most of the stronger studies involve injectable or medical-grade application rather than over-the-counter serums. GHK-Cu, a copper peptide not mentioned in this video, has a stronger topical evidence base than most of the products reviewed here (Pickart et al., 2015, Journal of Aging Science).

The pharmacist framing adds implied authority, but product ratings without disclosed methodology, ingredient sourcing, or conflicts of interest are still opinion content. If you are considering any peptide-adjacent ingredient for skin aging, the evidence hierarchy matters: randomized controlled trial data beats in-vitro data beats a ppm number on a label.