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.
Where human data exists for GHK-Cu, endpoints are frequently surrogate measures rather than outcomes people care about. A change in a biomarker is a reason to run a larger trial, not a reason to conclude the trial would succeed.
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.
