GHK-Cu doses in studies: what researchers actually used

Researchers have rarely reported a clear GHK-Cu dose in people. The human studies mostly used a gel, a cream, or a mixed scalp injection, and the abstracts often leave the amount out. The one clearly stated dose in our sources comes from mice: 15 mg/kg.^[1]

What the human studies gave

The human evidence is thin, and almost all of it is from the skin-cream or gel side.^[2][3]

• Diabetic foot ulcers (1994): a GHK-copper gel was applied daily after debridement. The abstract does not give the concentration.^[4]
• After CO2 laser resurfacing (2006): GHK-Cu skin-care products were used for 12 weeks in a randomised trial in which 13 patients finished. Our sources don't cover the amounts used.^[5]
• Scalp injection mix (2018): 1000 people got a mix with six ingredients once every 3 weeks for 8 sessions. The GHK-Cu dose is not given in the abstract.^[6]
• Case report (2016): one 59-year-old man had a mixed cosmetic solution applied with a spray device weekly for 12 weeks.^[7]
• Acne scar gel (2025): females used a topical blend that included copper tripeptide-1 for 45 days. The number of participants was not stated in the abstract.^[8]

So for people, the schedules are known better than the amounts. Daily, weekly and every 3 weeks all appear, but the actual GHK-Cu quantity is mostly missing.^[4][6][7]

What the animal work used

The clearest number comes from a mouse study. Mice aged 20-21 months old were given GHK-Cu 15 mg/kg either intraperitoneally for 5 days or intranasally for 8 weeks.^[1]

Intranasal dosing improved escape latency in a spatial task in both sexes. Intraperitoneal dosing gave only a transient improvement in males.^[1]

This is a preprint on Research Square, so it has not been peer-reviewed.^[1]

Other animal and lab work looked at colitis in mice, inflammation in zebrafish larvae, and lifespan in worms.^[9][10][11] Zebrafish and worms are not mammals.^[10][11]

Why the doses are hard to compare

A few problems make it hard to line these studies up.

• Many products are blends. The scalp mix held VEGF, bFGF, IGF, KGF, thymosin beta-4 and copper tripeptide-1, so its effect cannot be pinned on GHK-Cu alone.^[6]
• The scar gel also held copper tripeptide-1 with L-carnitine L-tartrate, alpha-glucosyl hesperidin and sodium hyaluronate. It was uncontrolled and not GHK-Cu alone.^[8]
• The results were mixed. The 1994 gel trial reported median ulcer-area closure of 98.5% versus 60.8% with vehicle (p < 0.05), but it is old and I found no replication.^[4]
• In the laser trial, objective measures showed no reduction in redness or improvement in wrinkles or skin quality. Patient questionnaires showed higher satisfaction with skin quality (p = 0.04).^[5]
• A 2026 systematic review says the human literature is thin and fragmented, and that most randomised trials are small and use facial cosmetic creams.^[2]

The body also makes GHK itself, so papers that only measure its levels do not show that taking it works.^[12]

What regulators say about injected products

FDA's category 2 page says compounded injectable GHK-Cu may carry immune-reaction risk from aggregation and impurities, and that there are limited human data to inform safety.^[13]

As of 2026-10-09, that page lists GHK-Cu for injectable routes among nominated-but-withdrawn substances it had flagged for significant safety risk.^[13]

For non-injectable routes, the FDA 503A list updated 2026-05-14 has GHK-Cu back in Category 1 (under evaluation). FDA intends to consult its compounding advisory committee before the end of February 2027.^[14]

A 2020-04-01 FDA warning letter to Tailor Made Compounding LLC listed GHK-Cu among bulk substances the firm compounded that were not eligible for the 503A exemptions.^[15]

Reviews of peptide use in sports medicine say rigorous human safety data are lacking for unapproved peptides including GHK-Cu.^[16][17]

The bottom line

• The only clearly stated dose in our sources is 15 mg/kg in mice, given intraperitoneally for 5 days or intranasally for 8 weeks.^[1]
• Human studies report schedules such as daily gel, weekly spray and every 3 weeks for 8 sessions, but the GHK-Cu amount is mostly not given.^[4][7][6]
• No randomised trial in people has tested injected GHK-Cu on its own.^[2][6]
• Long-term safety, copper exposure from repeated injection, and drug interactions are unstudied.^[13]
• Our sources do not report a clear GHK-Cu amount for people.^[4][6]
• This post reports what studies and regulators say. It is not advice to take, inject or dose anything.