GHK-Cu is a naturally occurring copper-binding tripeptide with a development status of "cosmetic use / preclinical". The Institute rates the strength of its published evidence as moderate. A copper-binding tripeptide found in human plasma, extensively studied in skin-repair and cosmetic contexts.
The distinction that matters most when reading about GHK-Cu is between what has been demonstrated and what has been proposed. Mechanistic plausibility is not evidence of effect, and a compound can have a well-characterised receptor interaction while producing no measurable clinical benefit. That gap is where most of the confusion in this space lives.
Much of the GHK-Cu literature comes from a small number of research groups, which limits how independently the findings have been replicated. Concentration of authorship is not evidence of error, but it does constrain how much weight any single result can carry.
The Institute has independently tested 4 GHK-Cu samples from 4 companies. 75% met their label claims on purity and content. Measured purity ranged from 69.1% to 98.8%, averaging 90.7%. 1 sample failed verification outright. Every specimen is published in full, including the laboratory that ran it.
The Peptide Institute is an independent research institute. We do not sell products, we do not accept vendor sponsorship, and we publish results that reflect badly on companies as readily as results that do not.
