OS-01

Also known as: Peptide 14, Pep 14, OneSkin peptide

Evidence: Clinical

PeptideLab is an educational platform for learning about peptides. The information here is for educational and research purposes only. It is not medical advice, diagnosis, or treatment, and PeptideLab does not claim to diagnose, treat, cure, or prevent any disease or health condition. Many peptides discussed have not been approved for human use by the FDA or other regulatory bodies. Consult a qualified healthcare professional before making any health-related decision.

Overview

Topical decapeptide (ETAKHWLKGI-NH2, Peptide 14) from OneSkin that lowered senescence markers in human skin models; two small developer-run RCTs reported better skin barrier function.

OS-01, also called Peptide 14, is a 10-residue amidated peptide found by OneSkin through a screen for compounds that reduce senescence in progeria and aged fibroblasts (Zonari et al., 2023). In human skin explants a 0.01% formulation lowered senescence and SASP markers, thickened the epidermis and reduced a DNA methylation age estimate. It is senomorphic: it did not change apoptosis genes or cell counts, so it does not kill senescent cells. Human data come from OneSkin trials: a split-face, vehicle-controlled study in 22 people (Zonari et al., 2024), a 60-woman randomized trial against a commercial moisturizer (Zonari et al., 2025) and an uncontrolled eye-cream study in 22 people. Every paper has OneSkin founders as authors, and independent replication is lacking.

Benefits

Improved skin barrier function and lower TEWL (human RCTs, topical, developer-run), less periorbital wrinkle indentation versus vehicle (human RCT, n=22), lower senescence markers and DNA methylation age (ex vivo human skin), reduced senescence burden (fibroblasts, in vitro)

Dosing reference

Research dose: Topical. 0.01% w/v in the ex vivo formulation; the clinical products' concentrations are not stated in the abstracts. A 1 mM solution (about 0.12%) was used for patch testing.

Topical only. The 60-person trial applied a body formulation twice daily for 12 weeks; the eye-cream study used a dime-sized amount twice daily for 12 weeks. The ex vivo work used 0.01% w/v, and the eye cream is described as holding a higher concentration than earlier formulations.

Mechanism

Senomorphic, not senolytic. In fibroblasts Peptide 14 reduced the share of cells reaching late senescence, apparently by arresting the cell cycle and enhancing DNA repair, and the authors link this to modulation of a PP2A subunit and PP2A/AKT signaling (Zonari et al., 2023). The same paper found no change in apoptosis or autophagy genes, which contradicts the old claim of selective apoptosis of senescent cells. In immune cells in vitro it shifted PBMCs toward a Th2/Treg profile with more IL-10 and pushed macrophages toward an M2-like state (Alencar-Silva et al., 2024). The mechanism work is cell culture and explants, all from the developer's group or collaborators.

Evidence

Clinical: at least one published human trial or an approved drug

Split-face, double-blind, vehicle-controlled study, 22 participants, 12 weeks: lower TEWL than vehicle and less periorbital wrinkle indentation on the OS-01 side (Zonari et al., 2024)
Randomized, double-blind trial in 60 women aged 60 to 90 versus a commercial moisturizer, 12 weeks: better barrier function and hydration, and lower blood IL-8 (Zonari et al., 2025)
In ex vivo aged human skin, 0.01% topical formulation lowered senescence and SASP markers and DNA methylation age; in fibroblasts, reduced senescence without killing cells (Zonari et al., 2023)
Mostly non-toxic to fibroblasts and keratinocytes up to 100 uM; negative Ames, micronucleus and karyotype tests; no reactions in a 54-person patch test at 1 mM (Zonari et al., 2022)
Human-trial status: two small randomized trials and one uncontrolled study, all run by the developer (OneSkin); no independent trial

References

Side effects

No visible reactions in a repeated insult patch test with 1 mM peptide (n=54); negative Ames, micronucleus and karyotype tests; slight reduction in MeWo and HeLa cancer cell proliferation in vitro (Zonari et al., 2022). In the 60-woman trial, 3 of 30 in the OS-01 group withdrew with moderate skin reactions (rash, pimples, dry patches), possibly from the product or the supplied cleanser (Zonari et al., 2025). Commonly reported (anecdotal): mild irritation.

Storage

Storage: Room temperature, away from light
Lyophilized: 2 years at room temp
Reconstituted: N/A (ready to use)

Pharmacology

Half-life: No published pharmacokinetic data in any species
Bioavailability: Up to 2% of the applied peptide reached the dermis of ex vivo human skin from the test formulation (Zonari et al., 2023); no systemic exposure data
Molecular weight: 1181.39 Da
Sequence: Glu-Thr-Ala-Lys-His-Trp-Leu-Lys-Gly-Ile-[NH2]