GHK-Cu Lash/Brow Peptide (Myristoyl Pentapeptide-17)
A lipidated cosmetic peptide (myristoyl pentapeptide-17) used in topical eyelash and eyebrow serums, promoted to lengthen and thicken lashes by supporting keratin gene expression in the follicle. A common cosmetic ingredient with minimal independent clinical evidence.
01 Overview
Myristoyl pentapeptide-17 is a signal peptide conjugated to myristic acid for skin penetration, marketed in 'lash-boosting' serums as a gentler alternative to prostaglandin-analogue lash drugs. It is proposed to upregulate keratin production in the hair follicle, encouraging longer, denser lashes and brows.
Unlike prescription prostaglandin analogues, it is a cosmetic ingredient with limited peer-reviewed support; efficacy claims lean on manufacturer data and user reports. Local eye-area irritation is the main practical concern, and it lacks the periorbital pigmentation/iris colour risks associated with prostaglandin lash drugs.
02 Mechanism
Myristoylated signal peptide proposed to stimulate keratin gene expression and follicular activity, promoting eyelash and eyebrow growth.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Cosmetic serum | 100–1000 ppm | Transdermal | Low cosmetic concentration in lash/brow serums, applied to the lash line once daily. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Longer, denser lashesMarketed and anecdotally reported to lengthen and thicken lashes over weeks; independent data are limited. | Modest cosmetic improvement | Anecdotal | |
| Brow conditioningUsed similarly on eyebrows for improved fullness. | Cosmetic | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Eye-area irritationRedness, itching or stinging of the eyelid margin. | Mild | Uncommon | Anecdotal | |
| Contact allergyRare allergic reaction to peptide or serum excipients. | Mild | Rare | Unconfirmed |