GHK-Cu

GHK-Cu is a tiny copper-carrying protein fragment that occurs naturally in your blood, saliva, and urine. Your body uses it as a signal for tissue repair — when levels are high, it triggers healing and regeneration. The problem is that levels drop sharply with age, falling by more than half between your twenties and sixties, which researchers believe contributes to slower healing and the visible signs of aging.

For skin, the evidence is more developed than almost any other peptide. GHK-Cu has been shown in clinical studies to increase collagen production, improve skin thickness, reduce fine lines, and speed up wound healing. It's already a common ingredient in high-end skincare products, though the concentrations used in topical serums are generally much lower than what's used in research.

Hair is another well-studied application. GHK-Cu appears to reactivate dormant hair follicles and increase follicle size, which translates to thicker, denser hair over time. Results with topical application to the scalp are slower than pharmaceutical hair loss treatments, but without the side effects associated with those drugs.

What sets GHK-Cu apart from most peptides is its reach. Research suggests it influences the expression of over 4,000 genes, many of which are involved in reducing inflammation and switching the body from a breakdown state to a repair state. This wide-ranging effect on gene activity is why some researchers consider it one of the most interesting anti-aging compounds currently being studied.