GHK is a tripeptide made of three amino acids: glycine, histidine and lysine (Gly-His-Lys). It occurs naturally in human plasma, saliva and urine. Loren Pickart first isolated it from human plasma in the early 1970s and reported it in Nature New Biology in 1973, describing a serum factor that prolonged the survival of cultured liver cells (Pickart & Thaler, 1973). That origin is why you still see the old name "liver cell growth factor" attached to it.
You will more often see it written as GHK-Cu or by its cosmetic ingredient name, Copper Tripeptide-1. GHK has a high affinity for copper(II) ions and is usually handled as that copper complex. The molecule itself is small, with the formula C14H24N6O4 (PubChem CID 73587).
Why the copper matters
The copper isn't incidental. GHK's structure lets it bind and carry copper ions in a form the body can use, delivering the metal into and out of cells while keeping its reactive chemistry in check. A large 2015 review by Pickart and colleagues lays out the proposed biology: GHK-Cu stimulates synthesis of collagen and other dermal components such as dermatan sulfate, chondroitin sulfate and the proteoglycan decorin, and it modulates both matrix metalloproteinases and their inhibitors (Pickart, Vasquez-Soltero & Margolina, *BioMed Research International*, 2015).
The same review reports that GHK levels in plasma fall with age, from roughly 200 ng/mL around age 20 to about 80 ng/mL by age 60. That age decline is part of why it has drawn interest as a repair and anti-aging agent. Gene-expression work cited in the review found GHK could shift the activity of a large number of human genes, including a pattern that raised DNA-repair genes (47 stimulated, 5 suppressed in one analysis). Those are interesting signals, not proof of a clinical outcome.
What the human evidence looks like
Much of the strongest data is preclinical: cell culture and animal wound-healing studies showing faster repair, reduced inflammation, antioxidant effects and new blood-vessel growth. On the human side, the most-cited result is a topical comparison. In a study summarized in the 2015 review, a facial cream with GHK-Cu produced collagen increases in 70% of the women treated, compared with 50% for a vitamin C cream and 40% for retinoic acid.
Read that in context. Most controlled human work on GHK is small, focused on skin appearance, and often tied to the researchers and companies who developed the peptide. A broader 2018 review covers its skin-regenerative and other proposed actions and is a good map of the field (Pickart & Margolina, *Cosmetics*, 2018). Claims you will see online about systemic anti-aging, hair growth or injury recovery in people run well ahead of the published human trials.
Regulatory and quality notes
GHK-Cu, as Copper Tripeptide-1, is an established cosmetic ingredient and appears in many topical skin and hair products. It is not an approved drug for ingestion or injection, and a synthetic version (prezatide copper acetate) studied decades ago for wound healing did not become a marketed medicine. Material sold as raw peptide is research-use-only and not intended for human consumption. GHK-Cu is not listed on the World Anti-Doping Agency Prohibited List, though anyone subject to testing should confirm current status directly.
For anyone buying it, the practical issue is identity and purity. Copper peptide is sold by many suppliers at varying quality, and "GHK-Cu" can mean different things depending on copper loading and formulation. A current certificate of analysis showing identity and purity from an independent lab is the baseline. peptideone aggregates third-party COAs and vendor ratings to make that easier to check; we don't sell or test anything ourselves.
Nothing here is medical or dosing advice.