Glycyl-Histidyl-Lysine, Copper Tripeptide-1
Evidence Grade C — Moderate human evidence. 241 published studies, 82 human. 2 registered clinical trials.
GHK is a naturally occurring tripeptide that binds copper, found in human blood. In the cosmetic industry it is known as 'copper tripeptide-1' and is a common ingredient in anti-ageing skincare products. This entry covers the free peptide form without copper; the copper-complexed version (GHK-Cu) is described separately. It has no pharmaceutical approval.
241 published studies: 82 human, 47 animal, 44 in-vitro, 18 reviews
GHK has no pharmaceutical authorisation. Small cosmetic studies of the copper-complexed form (GHK-Cu) have reported improvements in skin appearance measures. No pharmaceutical clinical trials for injectable use have been completed.
As with GHK-Cu (#85), the cosmetic evidence base for topical use should be distinguished from claims about injectable use. Gene expression profiling studies have reported broad effects, but observational genomic changes do not constitute evidence of therapeutic efficacy. This entry overlaps substantially with GHK-Cu (#85).
Research suggests GHK's biological activity is primarily mediated through its copper-binding capacity. Gene expression analyses have reported broad effects on gene regulation, but these are observational genomic studies and do not establish specific therapeutic mechanisms. The distinction between the free peptide and the copper-complexed form (GHK-Cu) is pharmacologically relevant.
Research suggests GHK has been studied primarily in the context of topical skincare, where small studies (21-71 participants) of the copper-complexed form have shown improvements in skin appearance. Gene expression profiling has reported broad effects, though these analyses were performed on cancer cell lines rather than normal tissue. The safety record in topical cosmetic use is excellent over approximately 30 years. However, no large randomised controlled trials exist, no systemic pharmacokinetic data are available for injectable use, and most research originates from a single investigator group. Blood levels naturally decline with age, providing biological plausibility for supplementation, but plausibility is not proof of benefit.
Topical GHK-Cu Gel for Acute Skin Wound Healing
Trial Assessing the Impact on Facial Skin Quality, Hydration, and Skin Barrier of Three (3) Hydrafacial Treatments in Adults of All Skin Types.
The information on this page is provided for educational and research reference purposes only. This is not medical advice. Always consult a qualified healthcare professional before making any health-related decisions.
GHK-Cu has no pharmaceutical authorisation from any regulatory agency. It is widely available as a cosmetic ingredient in over-the-counter skincare products, where it is marketed for skin conditioning. A small study comparing GHK-Cu cream to vitamin C and retinoic acid creams reported improvements in skin appearance measures. No pharmaceutical clinical trials for injectable GHK-Cu have been completed. The compound's cosmetic use (topical, in formulated skincare products) should be clearly distinguished from its unregulated availability as an injectable research compound. These represent fundamentally different risk profiles.
Epitalon has no marketing authorisation from any major regulatory agency. No controlled human clinical trials have been conducted. Animal lifespan studies in mice reported by the Khavinson group form the core evidence base. The telomerase activation claims are based on in vitro studies and mouse models from a single research programme. Independent replication of the key findings has not been published. The relationship between in vitro telomerase activation and any clinical outcome in humans is not established. Products available through unregulated channels lack pharmaceutical quality assurance.
FOXO4-DRI has no marketing authorisation. No human clinical trials have been conducted. The evidence comes from a single high-profile publication (Cell, 2017) demonstrating effects in three mouse models. The senolytic field is an active area of pharmaceutical research, but FOXO4-DRI faces significant challenges for clinical translation, including its large size (46 amino acids), manufacturing complexity, and the absence of human pharmacokinetic or safety data. Products available through unregulated channels — which would need to reliably synthesise a 46-amino-acid all-D-amino-acid peptide — face exceptional quality assurance challenges.
