Research library
Peptides (topical and other)
- What it is: Short chains of amino acids, such as copper peptides, that are included in lotions and serums applied to the scalp.
- Form: Topical (other)
- How it works: Peptide signalling to the follicle and its surrounding tissue (proposed)
- Evidence (androgenetic alopecia): Early human studies
- In United States: Not yet verified
- Sources: 4 published sources, each one linked
Not yet reviewed by a clinician
The research: findings, limits and side effects
Peptides are short chains of amino acids. For pattern hair loss they are mostly found in lotions, serums and shampoos applied to the scalp, including copper-bound peptides such as GHK-Cu and laboratory-made peptides designed to resemble the body's own signalling molecules. Products usually combine a peptide with other ingredients and differ in what they contain. Peptides sold for injection are not covered here. See the sourced sections below for what is known about the study results and the risks.
Evidence for androgenetic alopecia: Only small, early-phase or uncontrolled human studies have been reported. Human studies are small, and most tested peptides combined with other ingredients, so the contribution of the peptide itself is unclear.
Status in United States
- Not yet verifiedAndrogenetic alopecia. We have not yet checked how peptide products used on the scalp are regulated in the United States.
General
A review of topical cosmetic hair-growth products describes peptide ingredients including biotinyl-GHK (a biotin-linked form of the gly-his-lys peptide, described as a matrikine) and the biomimetic peptide acetyl tetrapeptide-3, and notes that almost all formulations containing these peptides also contain other vitamins, minerals or chemical additives.
Source: Topical Alternatives for Hair Loss: Beyond the Conventional
How it works
The same review describes biotinyl-GHK as helping to anchor the hair through adhesion proteins such as laminin 5 and collagen IV, and an ingredient containing acetyl tetrapeptide-3 as increasing extracellular matrix proteins such as collagen type III and anchoring fibres such as laminin and collagen VII in the dermal papilla.
Source: Topical Alternatives for Hair Loss: Beyond the Conventional
A laboratory study reported that a copper tripeptide complex (AHK-Cu) stimulated the elongation of human hair follicles kept alive outside the body and the proliferation of cultured dermal papilla cells. The authors proposed that this may occur through stimulating the proliferation of these cells and preventing their programmed death. This was a laboratory study, not a study in people.
Source: The effect of tripeptide-copper complex on human hair growth in vitro
Potential benefit
A placebo-controlled study treated 45 patients with male pattern hair loss once a day for 6 months with a complex of 5-aminolevulinic acid and the GHK peptide at 100 mg/ml or 50 mg/ml, or with placebo. It reported increases in hair count of 52.6 (p<0.05) and 71.5 (p<0.05) in the two treated groups and 9.6 in the placebo group, no statistically significant difference in hair length or hair thickness among the three groups at 6 months, and no adverse event in any group. The tested product combined the peptide with another active substance.
Source: Efficacy of a Complex of 5-Aminolevulinic Acid and Glycyl-Histidyl-Lysine Peptide on Hair Growth
The review cites a 24-week, triple-blinded randomised controlled study in 32 men and women with mild-to-moderate androgenetic alopecia, in which a herbal extract containing biochanin A, acetyl tetrapeptide-3 and ginseng extracts showed comparable efficacy to 3% minoxidil solution, with no local adverse reactions observed.
Source: Topical Alternatives for Hair Loss: Beyond the Conventional
Limitation
The review concludes that, because the formulations also contain other ingredients, it is challenging to discern how much the peptides contribute. It lists methodological flaws in the studies, including limited sample size, lack of appropriate comparison groups, qualitative rather than quantitative measures of hair regrowth and conflicts of interest from company sponsorship, notes a lack of head-to-head comparison with standard treatments, and states that more well-designed comparative studies are needed.
Source: Topical Alternatives for Hair Loss: Beyond the Conventional
A systematic evidence-mapping review of the copper peptide GHK-Cu (across all uses, not only hair) found that laboratory and animal data consistently support effects on tissue repair, but that the clinical evidence remains sparse; the human studies it identified were small, and the one hair study was of eyebrows in 18 healthy participants. It concludes that, until controlled clinical efficacy is demonstrated, GHK-Cu should be regarded as unproven rather than as a clinically validated regenerative drug.
Adverse effect
The GHK-Cu review notes that copper is a recognised contact sensitiser in susceptible individuals, and that a penetration-enhancing vehicle or a breached skin barrier increases the relevant exposure.
Warning
The GHK-Cu review states that injectable copper-peptide preparations supplied outside an approved marketing authorisation sit outside any defined evidentiary or quality framework.
General information only, not medical advice, and not yet reviewed by a clinician. Talk to a qualified clinician about your own situation.
