Most compounds covered in this publication have research histories measured in years. GHK-Cu’s is measured in decades. The tripeptide was first isolated in 1973 by researcher Loren Pickart, who found that a component of human plasma caused old liver tissue samples to synthesize proteins at rates resembling much younger tissue — an observation that kicked off a research program still active today.

What Pickart Actually Found

The compound Pickart isolated was glycyl-L-histidyl-L-lysine — GHK — a naturally occurring tripeptide present in human plasma, saliva, and urine that declines measurably with age. GHK binds copper with high affinity, forming the complex now marketed as GHK-Cu, and that copper-binding property turns out to be central to its biological activity.

The Wound-Healing Literature

Follow-up research through the 1980s and 1990s, particularly work by Maquart and colleagues, demonstrated that GHK-Cu at very low, nanomolar concentrations stimulates both synthesis and breakdown of collagen and glycosaminoglycans in wound models — a dual action that helps explain its role in tissue remodeling rather than simple collagen accumulation. Controlled wound-chamber studies in animals showed collagen content increases of several hundred percent compared to untreated controls.

“Fifty years is long enough to separate a real, replicated effect from a fluke. GHK-Cu’s collagen and wound-healing activity has cleared that bar many times over.”

— a peptide researcher who reviewed the literature for this piece

Where Human Evidence Actually Exists

Unlike several compounds covered in this newsletter, GHK-Cu has real human clinical trial data, not just animal models — published research has reported improved healing of skin ulcers in diabetic patients treated with GHK-Cu, and it has long been used in dermatology and cosmetic formulations on the strength of that human evidence, alongside a much larger animal literature.

Where the Evidence Thins Out

The compound’s more recent marketing has expanded well past wound healing and into broad anti-aging and cognitive-health claims, an area where the evidence is considerably thinner than the wound-healing literature and rests more on proposed mechanisms — antioxidant activity, gene-expression modulation — than on the kind of controlled human outcome trials that exist for its dermatological use.

The pattern is a familiar one by now: a genuinely old, genuinely replicated core finding, with newer and much less-supported claims layered on top of it in current marketing.