GHK-Cu Injection Dosage Chart, Side Effects & FDA Status
GHK-Cu is a copper-binding tripeptide first isolated from human plasma in the 1970s and studied since for its role in tissue repair and skin remodeling. Most of what's actually been tested in humans is topical: one small randomized trial and one ongoing Phase 2 wound-healing study, both using creams or gels. The injectable use that drives most of today's search volume has no completed human trial behind it at all, and it's the exact route the FDA flagged as having "limited data in humans" when reviewing it for compounding.
Reviewed by the PepGuard team · Last reviewed Jul 28, 2026
Naturally occurring copper-binding tripeptide (Glycyl-L-Histidyl-L-Lysine, complexed with Cu²⁺) · also sold as Copper Tripeptide-1, Copper Peptide GHK-Cu, GHK-Copper
Photo: Mathilde Langevin / UnsplashWhat's actually cited, by route.
The topical rows below come from a real trial and an active FDA-registered study. The injectable rows are vendor-reported only.
| What's cited | Range |
|---|---|
| Topical, wrinkle-reduction RCT (nano-carrier serum) | twice daily for 8 weeks, n=40 women aged 40-65 |
| Topical, active Phase 2 wound-healing trial | 0.1% w/w gel, once daily for 14 days (ClinicalTrials.gov NCT07437586, recruiting) |
| Commonly cited injectable range (vendor-reported, no human trial exists) | 1-2 mg/day, subcutaneous |
| Commonly cited injectable upper range (vendor-reported, no human trial exists) | 2-4 mg/day |
| Commonly cited injectable cycle length (vendor-reported) | 4-12 weeks |
Two very different bodies of evidence get conflated under "GHK-Cu dosage," and keeping them separate matters. The topical concentrations below come from an actual randomized trial and an active FDA-registered Phase 2 study, not community estimates. The injectable figures are what's most frequently cited in vendor and community protocols; no completed human trial has tested injectable GHK-Cu at any dose, which is consistent with the FDA's own "limited data in humans" language for that route.
What you're searching for isn't what got studied.
Most GHK-Cu search volume is about injection dosage. Most GHK-Cu clinical evidence is topical. A small randomized trial (n=40 women, 8 weeks) tested a twice-daily nano-carrier serum against a vehicle control and a commercial Matrixyl® 3000 product, and an FDA-registered Phase 2 trial is currently recruiting to test a 0.1% w/w gel for wound healing. Neither of those is an injection.
No completed human trial, of any size, has tested injectable GHK-Cu. That's not an incidental gap: it's the FDA's own stated reason for treating the injectable route differently from the topical one when it reviewed GHK-Cu for compounding (see the regulatory section below). If a page tells you an exact injectable dose worked in a study, ask which study, because we couldn't find one.
Including the one contraindication that matters.
Copper is essential in small amounts, but exogenous copper exposure is medically contraindicated in Wilson’s disease.
| Signal | Frequency | Context |
|---|---|---|
| Skin irritation or redness at the topical application site | occasionally reported | General to active topical cosmetic ingredients; the published wrinkle-reduction trial did not report a detailed adverse-event breakdown in its available abstract. |
| Injection site reaction (for injectable/vendor use) | occasionally reported | Anecdotal only. General to subcutaneous injection, not specific to GHK-Cu, since no completed human trial has tested the injectable route at all. |
| Immunogenicity from aggregation or peptide-related impurities (injectable route) | unknown / not studied | This is the FDA's own stated reason for withdrawing injectable GHK-Cu's Category 2 nomination: "there are limited data in humans to inform safety-related considerations." |
| Systemic copper accumulation from injectable or high-dose use | unknown / not studied | No independently verifiable human pharmacokinetic study on injectable GHK-Cu and serum copper levels was found. Exogenous copper is medically contraindicated in Wilson's disease (an inherited copper-metabolism disorder) regardless of route. |
| Long-term or cumulative effects beyond the study window | unknown / not studied | No published trial has followed subjects for longer than the 8-14 day/week windows described in the dosage section above. |
Not FDA-approved as a drug. Split regulatory path by route of administration.
GHK-Cu has never been approved by the FDA for any use. Its compounding status is unusual among research peptides because it's split by route of administration rather than treated as one substance. Non-injectable (topical/cosmetic) GHK-Cu sits on the FDA's 503A "Category 1" bulk drug substance list (substances under evaluation for compounding). It was briefly removed from Category 1 on April 22, 2026 after its nominators withdrew their nomination, but on May 5, 2026 one nominator clarified it only meant to withdraw the injectable-route nomination and wanted to keep the non-injectable one, so non-injectable GHK-Cu was added back to Category 1. The FDA has said it intends to consult the Pharmacy Compounding Advisory Committee (PCAC) before the end of February 2027 on whether to add GHK-Cu to the permanent 503A bulks list. Injectable GHK-Cu took a different, more restrictive path: it was nominated for "Category 2" (substances posing potential significant safety risks) and is now listed among bulk substances nominated but withdrawn, with the FDA's own stated reason being that "compounded injectable drugs containing GHK-Cu may pose risk for immunogenicity due to the potential for aggregation and peptide-related impurities" and that "there are limited data in humans to inform safety-related considerations." In plain terms: the route almost everyone is searching dosage for is the one route the FDA says it doesn't have enough human data on.
Every claim above, traced back.
Primary studies, an active trial registry entry, FDA compounding records, and one medical reference. Click through and check them yourself.
GHK-Cu questions, answered.
There is real human evidence, but it's narrower than most product pages imply. A small randomized trial (n=40 women) found a topical GHK-Cu serum reduced wrinkle volume compared to both a vehicle control and a commercial Matrixyl® 3000 product, and an FDA-registered Phase 2 trial is currently recruiting to test a 0.1% topical gel for wound healing. What doesn't exist is any completed human trial of injectable GHK-Cu, which is the form and route most people searching "GHK-Cu dosage" are actually asking about.
It depends entirely on the route, and the two shouldn't be conflated. The topical concentrations that have actual trial data behind them are a twice-daily nano-carrier serum (8-week RCT) and a once-daily 0.1% w/w gel (ongoing Phase 2 trial). The 1-4 mg/day injectable figures that circulate in vendor and community protocols have no clinical trial behind them at all.
No. It has never been approved by the FDA as a drug. Its compounding status is unusually split: non-injectable GHK-Cu sits on the FDA's 503A Category 1 list (under evaluation, with a Pharmacy Compounding Advisory Committee review expected before the end of February 2027), while injectable GHK-Cu was nominated for the more restrictive Category 2 and is now listed as withdrawn, with the FDA citing "limited data in humans" for that route specifically.
We could not find an independently verifiable human study measuring serum copper or ceruloplasmin levels after GHK-Cu use, despite that specific claim circulating widely on vendor sites, so we're not repeating it as fact here. What is medically established is that exogenous copper exposure is contraindicated in people with Wilson's disease, an inherited disorder of copper metabolism, regardless of the source or route.
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