Reviewed & approved by Dr. Nova Reyes · Last checked 2026-10-15. ← Back to Evidence Library
GHK-Cu (copper peptide): what the evidence says
At a glance
What it is: a tiny peptide (3 amino acids: glycine, histidine, lysine) bound to copper. It occurs naturally in the body. It's a common ingredient in skin creams. It is also sold as an injectable "research chemical." R1
What the evidence says: on skin, small and mixed human data. As an injection, essentially untested in people. R2, R3
Biggest risks: for injections, not knowing what's in the vial and having no human safety data. It is reported to help new blood vessels grow, which helps healing but could in theory also feed a tumor. This hasn't been studied in people. R4, R10
| Rating | |
|---|---|
| Human Human evidence: topical (on the skin) | Very limited (mixed results): one 13-person randomized study (human, on the skin after laser resurfacing) found no difference on objective or blinded measures; only patient satisfaction differed R2 |
| Human Human evidence: injected | No human data (no human studies at all; animal studies only) R2, R3 |
| Animal Animal evidence | Very limited: three verified rat studies (wound chamber, knee ligament, irradiated skin), mixed results; much of the review literature from one company-affiliated author R3 |
| Regulatory | Not FDA-approved as a drug · not named on WADA list R7, R8 |
| Established human dose | Unknown Unknown |
Evidence verdict: Topical (on the skin): Very limited (mixed results) · Injected: No human data (no human studies at all; animal studies only, mainly rats) · Animal evidence: Very limited Card verdict: Very limited (topical skin creams, mixed results) · Injected use: No human data Card note: Varies by use, see page
Topical after laser resurfacing: Very limited. The only verified human study (13 people, randomized) found no difference in redness, wrinkles or skin quality on objective measures or by evaluators who didn't know who got what (blinded). Only patient satisfaction differed (p=0.04). It is too small to settle the question. (Miller 2006, PMID 16847171) R2
This page reports what studies used. It is not dosing advice.
Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source
What is it?
GHK is a three-amino-acid peptide that grabs copper tightly. The copper version, GHK-Cu, has been studied for decades for wound healing and skin repair. Caution [UNVERIFIED: exact start date] It is widely used in cosmetics. Putting a cream on your skin and injecting a peptide are very different, so we keep the two apart below. R1
Does it work?
On the skin (topical / cosmetic)
Human In people: the one randomized study we could verify (people were assigned to groups by chance) gave 13 people skin products with or without GHK-Cu after laser resurfacing. Evaluators who didn't know who got what (blinded) found no difference in redness, wrinkles or skin quality. People using GHK-Cu were more satisfied. R2
Caution Cosmetic-industry trials of GHK-Cu creams are widely cited, but we could not confirm them on PubMed. UNVERIFIED R2
Animal In animals: a GHK-Cu gel did not improve healing of irradiated skin flaps in rats. If anything, treated flaps had somewhat larger areas of dead tissue (not significant under the study's strict cutoff). R3
As an injection
Animal In animals: injected into wound chambers in rats, GHK-Cu increased collagen build-up. Injected into the knee after ligament surgery in rats, it helped at 6 weeks, but the benefit was gone by 12 weeks. R3
Human In people: essentially untested in people. We found no human study of injected GHK-Cu. R2
Is it safe?
- Human Topical: no safety problems were reported in the small skin study. But 13 people is far too few to judge. R2
- Unknown Injected: no human safety data. No formal animal toxicology (testing for serious harm, like organ damage) was found on PubMed. R5
- Caution Theoretical concern: a review says GHK stimulates blood vessel growth, which helps healing but could in theory also feed a tumor. The same review reports anti-cancer activity in lab studies. Neither has been tested in people. R4
- Caution Copper: injecting copper adds to the body's copper load. Unknown No study has measured this for injected GHK-Cu in people. R4
What we don't know
- Unknown A safe or effective human dose by injection
- Unknown Any controlled human trial of injected GHK-Cu
- Unknown Whether cosmetic results hold up in independent, published trials
- Unknown Long-term safety (including cancer, pregnancy and copper build-up)
Is it legal?
GHK-Cu is sold legally as a cosmetic ingredient. It is not FDA-approved as a drug. FDA flagged injectable GHK-Cu among compounding substances (pharmacies preparing custom medicines for individual patients, with a prescription) with safety risks. GHK-Cu for non-injectable routes is under FDA evaluation for compounding. An advisory committee review is planned before the end of February 2027. It is not named on WADA's (World Anti-Doping Agency) 2026 Prohibited List. WADA's S0 rule bans any non-approved substance not covered elsewhere. Whether that applies to GHK-Cu is not confirmed. As of Oct 15, 2026. R7, R8
What's in the vial?
Cosmetic creams and injectable vials are different products. With a gray-market injectable vial (one sold outside regulated channels), the contents are the biggest unknown. It could hold the wrong compound or amount, or the wrong copper content. It could also contain impurities, bacterial toxins or heavy metals. We test retail vials blind under the Open Peptide Standard. See results at /tests/. A passing test covers one batch, tested on one date. It does not mean the compound itself is safe. R10
What do users report?
Self-report, not evidence.
Unknown TBD. We'll only list this once we can cite a public source.
Study details
R2 Human Human studies: full table
Topical: one PubMed-verified randomized study. Injected: none found (PubMed search, Oct 15, 2026). UNVERIFIED Industry-sponsored cosmetic trials (facial and eye-area creams) are often cited in reviews; not confirmed against PubMed-indexed primary reports.
| Study | People | Route | Dose used | Follow-up | Reported | Limitations | Citation |
|---|---|---|---|---|---|---|---|
| Miller 2006, after CO2 laser resurfacing | 13 completed, randomized | Topical skin products | Caution Concentration not in abstract UNVERIFIED | 12 wk | No difference in redness, wrinkles, skin quality (blinded); higher patient satisfaction (p=0.04) | Very small | PMID 16847171 |
R3 Animal Animal and lab studies: dose table
These are doses researchers used, not recommendations. Animal doses don't convert simply to people. Many widely cited reviews are written by Loren Pickart, affiliated with the company Skin Biology (e.g., PMIDs 18644225, 29986520). Caution [UNVERIFIED: that Pickart discovered GHK]
| Route | Species | Model | Doses | Duration | Outcome | Citation |
|---|---|---|---|---|---|---|
| Injected into implanted wound chamber | Rat | Wound chamber | "Various concentrations" (Caution not in abstract) | — | Concentration-dependent increase in collagen and matrix | PMID 8227353 |
| Intra-articular (into the knee) | Rat (n=72) | ACL reconstruction | 0.3 or 3 mg/mL, weekly × 4 | 6 and 12 wk | Less laxity at 6 wk; no difference at 12 wk | PMID 25731775 |
| Topical gel, twice daily | Rat (13 treated, 10 control) | Irradiated skin flaps | Caution not in abstract | 10 d | No significant difference in vessels or VEGF; dead-tissue area 5.0 vs 3.8 cm² (treated vs control, p=.011, above the study's p<.01 cutoff) | PMID 23744835 |
R4–R6 Safety evidence and theoretical concerns
- R4 Review states GHK "stimulates blood vessel and nerve outgrowth" and lists "anti-cancer activities"; first author affiliated with R&D, Skin Biology (Pickart & Margolina 2018, PMID 29986520); the paper declares no conflict of interest. Treat as non-independent. Copper load from injection: Unknown no data.
- R5 Unknown No formal toxicology of injected GHK-Cu found.
R7–R8 Regulatory status (as of Oct 15, 2026)
- R7 FDA: no approved drug label found. Compounding: "GHK-Cu (for injectable routes of administration)" is on FDA's list of substances previously in Category 2 whose nominations were withdrawn; FDA cites immunogenicity risk "due to the potential for aggregation and peptide-related impurities" and "limited data in humans" (FDA page). "GHK-Cu (except for injectable routes of administration)" is being returned to Category 1 (under evaluation), and FDA intends to consult PCAC before the end of February 2027 (FDA 503A categories list, updated May 14, 2026).
- R8 WADA: not named in the 2026 Prohibited List. S0 covers "any pharmacological substance... with no current approval by any governmental regulatory health authority for human therapeutic use." UNVERIFIED whether WADA treats GHK-Cu as falling under S0.
R1, R10 Background and product quality
- R1 GHK (glycyl-L-histidyl-L-lysine), copper complex (Maquart 1993, PMID 8227353; Pickart 2008, PMID 18644225).
- R10 Open Peptide Standard panel: identity (mass spec), purity (HPLC), content, endotoxin, heavy metals, and sterility where offered; ISO/IEC 17025 lab; blind samples; results tied to a batch, and they expire. Unknown GHK-Cu results pending the first batch.
Full reference list (all verified on PubMed, Oct 15, 2026)
- Maquart FX, et al. J Clin Invest. 1993;92(5):2368-76. doi:10.1172/JCI116842. PMID 8227353
- Miller TR, et al. Arch Facial Plast Surg. 2006;8(4):252-9. doi:10.1001/archfaci.8.4.252. PMID 16847171
- Pickart L. J Biomater Sci Polym Ed. 2008;19(8):969-88. doi:10.1163/156856208784909435. PMID 18644225
- Parker NP, et al. Otolaryngol Head Neck Surg. 2013;149(3):384-9. doi:10.1177/0194599813492644. PMID 23744835
- Fu SC, et al. J Orthop Res. 2015;33(7):1024-33. doi:10.1002/jor.22831. PMID 25731775
- Pickart L, Margolina A. Int J Mol Sci. 2018;19(7):. doi:10.3390/ijms19071987. PMID 29986520
Disclaimer
This page is for education and harm reduction. It is not medical advice and not a recommendation to use GHK-Cu. Its safety as an injection in humans is not established. Please talk to a clinician you trust, especially if you have or have had cancer, have a copper-related condition such as Wilson disease, or are pregnant or breastfeeding. Seek care right away for a serious reaction, and report it to FDA MedWatch (https://www.fda.gov/safety/medwatch).