Overview

GHK-Cu is a tiny three-amino-acid peptide (GHK) bound to copper. It occurs naturally in human blood, and levels fall with age. It is mainly used in skin-care and hair products, where small studies suggest it may improve skin firmness and wrinkles; injectable use is popular online but has almost no human research.

How it works

Proposed, partly supported by lab data. GHK carries copper into cells; copper is needed by enzymes such as lysyl oxidase that build collagen and elastin ¹². Cell and animal studies report increased collagen and glycosaminoglycan production, effects on wound remodeling enzymes (MMPs and their inhibitors), antioxidant and anti-inflammatory activity, and gene-expression changes in thousands of genes in database analyses ¹². Effects in human skin are modest and mainly come from small cosmetic studies.

What research shows

Several small cosmetic studies in women (typically 12 weeks, facial or eye creams; e.g. n=71 and n=41) reported improved skin density, firmness and fine lines vs placebo or baseline; many were industry-linked and published only as conference abstracts ¹².
Randomized double-blind study (40 women, 8 weeks, twice-daily facial serum with GHK-Cu in a lipid nano-carrier): wrinkle volume fell more than with the plain serum or a Matrixyl 3000 product ¹¹.
Small comparison study of thigh skin reported more collagen production with a GHK-Cu cream than with vitamin C or retinoic acid creams ².
Vehicle-controlled trial of a GHK-Cu gel (Iamin) in diabetic foot ulcers reported more complete ulcer closure and fewer infections than vehicle ³.
Many cell and animal studies show wound-healing, anti-inflammatory and hair-follicle effects ¹².
No controlled human trials of injected GHK-Cu were found; FDA says human data are limited ⁵.

Doses studied in people

Published human studies are of topical creams, serums or gels; none of the sources checked here state the GHK-Cu concentration used, and there are no published human data for injected GHK-Cu.

Read this first: these are the amounts given to participants in published studies or written on official prescribing labels, reported for reference. They are not recommendations. Trial doses were chosen for specific patients under medical supervision, and a dose that is safe in one person can be harmful in another.

Weekly protocol

How the schedule looks week by week. Each chart says where it comes from: a prescribing label, a clinical trial, or a protocol commonly reported online.

Commonly reported injection protocol

Commonly reported, not studied

One week

D1D2D3D4D5D6D7

Once daily, 5 days a week · Subcutaneous injection

Syringe units (U-100)

Vial Water added

Dose by week

1.0 mgwk 1–4

1.5 mgwk 5–8

2.0 mgwk 9–12

Supplies for one course (estimate)

Counts only. This site does not sell or link to supplies.

Course: 8–16 weeks
Note: No published human data for injected GHK-Cu; human studies were topical. An alternative reported schedule is 2 mg three times a week; another guide lists 1–2 mg daily for 4–8 weeks, then 2–4 weeks off.
Source: PeptideDosages.com: GHK-Cu (50 mg vial) dosage protocol
Also: Peptide Protocol Wiki: GHK-Cu dosing protocols

Reference only, not a recommendation. Charts marked "commonly reported" describe what public sources say people use. They have not been tested in trials, and their safety and effect are unknown. Label and trial schedules were set for specific patients under medical supervision. Use the calculator only to understand the arithmetic.

Vial math

Many research vials hold 5 or 10 mg of powder. This table shows how much ends up in each mark on a U-100 insulin syringe for common amounts of added liquid. It is arithmetic only, not a dose.

Vial	Liquid added	Concentration	Per unit (0.01 mL)
5 mg	1 mL	5 mg/mL	50 mcg	Open in calculator
5 mg	2 mL	2.5 mg/mL	25 mcg	Open in calculator
5 mg	3 mL	1.67 mg/mL	16.7 mcg	Open in calculator
10 mg	1 mL	10 mg/mL	100 mcg	Open in calculator
10 mg	2 mL	5 mg/mL	50 mcg	Open in calculator
10 mg	3 mL	3.33 mg/mL	33.3 mcg	Open in calculator

More sizes: all vial sizes · How this works: Syringes and units · Reconstitution guide.

Safety

Topical cosmetic use has a long track record with few reported problems, mainly skin irritation ¹².
For injectable forms, FDA flags possible immunogenicity from aggregation and peptide impurities and says human safety data are limited ⁵.
Excess copper exposure is a theoretical concern with repeated injections; long-term safety of injection is unknown.

Report side effects of any drug or product to the FDA through MedWatch. For a possible poisoning in the US, call Poison Control at 1-800-222-1222.

Legal status

FDA: Not FDA-approved as a drug; widely sold as a cosmetic ingredient ¹.
Compounding: Injectable GHK-Cu was in 503A Category 2 until about April 22, 2026, when it was removed after the nomination was withdrawn; removal does not make it compoundable ⁶⁷. Reports conflict on the non-injectable form: FDA's list dated May 14, 2026 still shows "GHK-Cu (except for injectable routes)" in Category 1 ⁴, while law-firm summaries of the April 2026 notice say non-injectable GHK-Cu was being removed from Category 1 because that nomination was also withdrawn ⁶⁷. The PCAC is expected to review GHK-Cu before the end of February 2027 ⁸⁹.
Sports (WADA): Not specifically named on the 2026 Prohibited List ¹⁰.
Other: Legal as a cosmetic ingredient in the US and EU (INCI: copper tripeptide-1).

Rules change often. See Legal status of peptides for how these categories work.

History

Loren Pickart identified GHK in human plasma in 1973 while studying why young plasma affected liver cells differently from old plasma ¹. In the 1990s a company tested a GHK-Cu gel for diabetic foot ulcers ³. Since then it has become a common cosmetic ingredient ("copper peptides"). FDA placed injectable GHK-Cu in 503A Category 2 in 2023 and put non-injectable GHK-Cu in Category 1 (under evaluation) ⁴⁵.

Common questions

Is GHK-Cu an approved drug?

No. It is not FDA-approved as a drug, but it is widely sold as a cosmetic ingredient often called copper peptides ¹.

Does GHK-Cu work for skin?

Several small cosmetic studies in women reported better skin firmness, density and fine lines, though many were industry-linked or only conference abstracts ¹². In one 8-week randomized study of 40 women, a GHK-Cu serum reduced wrinkle volume more than comparison serums ¹¹.

Has injected GHK-Cu been studied in people?

No controlled human trials of injected GHK-Cu were found, and FDA says human data are limited ⁵. Published human studies used creams, serums or gels ¹²³.

Is GHK-Cu safe?

Topical cosmetic use has a long record with few reported problems, mostly skin irritation ¹². For injectable forms, FDA flags possible immune reactions from clumping and impurities and says human safety data are limited ⁵.

Can GHK-Cu be compounded?

Injectable GHK-Cu was removed from FDA's Category 2 list in April 2026, but that does not make it compoundable ⁶⁷. Reports conflict on the non-injectable form, and an FDA advisory committee is expected to review GHK-Cu before the end of February 2027 ⁴⁶⁷⁸⁹.

Is GHK-Cu banned in sport?

It is not specifically named on WADA's 2026 Prohibited List ¹⁰.

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