Acetyl Tetrapeptide-3 is a biomimetic cosmetic peptide used in hair care formulations, most notably as the peptide component of Capixyl (combined with red clover-derived biochanin A). Manufacturer-sponsored studies report a 17% increase in hair diameter and 46% reduction in hair loss at 12 weeks of topical use. It is classified as a cosmetic ingredient rather than a drug and is widely available in hair serums and topical products.
Category: Hair Growth / Cosmetic. Evidence rating: D (animal/preclinical only).
Clinical status: Marketed as a cosmetic ingredient. Manufacturer-sponsored clinical studies only; no independent peer-reviewed RCTs.
Acetyl Tetrapeptide-3 is thought to stimulate extracellular matrix proteins (particularly laminins and collagens) in the dermal papilla, strengthening the anchoring of hair follicles. When combined with biochanin A in Capixyl, the formulation also inhibits 5-alpha reductase, reducing local DHT…
Safety considerations: Generally well-tolerated as a topical cosmetic ingredient; No systemic side effects reported (topical application with minimal absorption); Rare reports of scalp irritation or contact dermatitis.
Reviewed by the PeptideAtlas Editorial Team.
| Production method | synthetic |
|---|---|
| Anti-doping status | not-listed |
| US regulatory status | Marketed as a cosmetic ingredient. Not FDA-regulated as a drug. |
No. Capixyl is a proprietary blend of Acetyl Tetrapeptide-3 plus biochanin A (a red clover isoflavone). The peptide is one component. Many of Capixyl's claimed effects may come from the biochanin A anti-androgenic activity rather than the peptide alone.
One manufacturer-sponsored comparison suggested Capixyl was comparable to 5% minoxidil, but this study was not peer-reviewed or independently conducted. Minoxidil has decades of independent clinical trial data.
No. It is formulated exclusively for topical use as a cosmetic ingredient. There is no safety data for injection.
Manufacturer studies suggest 12 weeks of consistent topical application. Individual results vary and independent confirmation is lacking.
Coverage on this site: The Best Peptide Beauty Products for Firmer, Hydrated Skin, According to Dermatologists, Acetyl Tetrapeptide: Multifunctional Peptide for Skin and Hair Health.