GHK-Cu

GHK-Cu is a naturally occurring tripeptide, three amino acids (glycine, histidine, and lysine) bound to a copper ion. Your body makes it on its own, and it circulates in the blood. It was discovered by the American researcher Dr. Loren Pickart in the mid-1970s, who found it in collagen tissue and proposed that it helps control both the building and the breakdown of collagen. Much of the foundational research traces back to his lab, a common theme with peptides. GHK levels are high in youth and fall sharply with age, dropping from roughly 200 units in young people to around 60 by age 65, which is one reason it is associated with the look of younger skin.

GHK-Cu is best known as a skin and aesthetic peptide. People read about it for firmer, plumper-looking skin, softened fine lines, and general skin rejuvenation, and it is often compared with ingredients like retinol and vitamin C. It has also been studied for wound healing: one study using a topical GHK-Cu gel on diabetic foot ulcers reported closure improving from about 60 percent to 98 percent. Interest in hair is more modest, and it is usually framed as a possible add-on rather than a replacement for established options. It is also the peptide people add to a BPC-157 and TB-500 pairing to make what the community nicknamed the glow stack. Some newer research is looking at connective-tissue repair beyond the skin.

GHK is actually a breakdown fragment of type 1 collagen, the most abundant collagen in the body. When tissue is damaged and collagen is being remodeled, GHK is released into the bloodstream, where it seeks out copper with such high affinity that it can pull copper ions off albumin, the body's main transport protein. It then delivers that copper exactly where repair enzymes need it, including enzymes for antioxidant defense and for cross-linking collagen and elastin. Unusually, it is described as regulating both the synthesis and the breakdown sides of collagen, which is what healthy remodeling requires. There is an aging angle too: as collagen stiffens with age, GHK can get trapped and released less, so less copper reaches repair sites, which some researchers frame as not just a marker of aging but part of its cause.

GHK-Cu is used both topically and by injection, and topical is the older and better-studied route, with a track record in cosmetics going back decades. The challenge with topical use is that GHK-Cu does not easily cross the stratum corneum, the skin's outer barrier. This is why it is often paired with microneedling: applying GHK-Cu right after microneedling is described as helping it get past that barrier and reach the skin below. Hydrating the skin with hyaluronic acid a few hours beforehand is also described as improving penetration, and some people pair topical use with red light therapy, which is discussed as synergistic. A practical quality tell is color: genuine GHK-Cu is blue because of the copper, so a colorless topical is a red flag. Injectable GHK-Cu also exists but has far less human data behind it. This is background on how it is used, not a recommendation.

The strongest human data for GHK-Cu is topical and aesthetic. One study reported that about 70 percent of people treated with topical GHK-Cu showed improved collagen synthesis, compared with roughly 40 to 50 percent for vitamin C, melatonin, or tretinoin, and there are additional studies on skin appearance and wound healing. The injectable form is much less proven in humans, so its safety and benefit are harder to state with confidence. As with several peptides, a large share of the foundational work comes from a single lab. Solid topical human data for skin, thinner evidence for injected use.

The topical form of GHK-Cu is widely sold in over-the-counter cosmetics and skincare and is not part of the FDA restriction that applies to injectable peptides like BPC-157 and TB-500. The injectable form is not FDA approved, and commentators expect it to come up in a later round of FDA discussion about compounded peptides rather than the first. Product quality varies, especially among research-chemical topicals, so the blue copper color and a reputable formulator are the checks people mention most.