Human studiesCopper peptide

GHK-Cu

Copper tripeptide-1

Common dose: 1–2 mg daily
Cycle: 6 weeks on, 3 off
Vial sizes: 50, 100 mg
Typical draw: 5 units50 mg with 2.5 mL, 1 mg

A naturally occurring copper-binding tripeptide found in human plasma. It is widely used in skin care as copper tripeptide-1.

Evidence. Small human studies exist for topical use (skin aging, wound gels). Injection rests on animal data and anecdote.

Status

Approval: Not approved as a drug in the US or EU; sold as a cosmetic ingredient (INCI name copper tripeptide-1).
US compounding: The nomination for injectable GHK-Cu was withdrawn, so it is no longer in FDA Category 2 (April 2026). Non-injectable GHK-Cu is under evaluation (Category 1), and FDA plans to consult its advisory committee by the end of February 2027.
Sport (WADA 2026): Likely banned in sportTopical cosmetic use isn’t banned. Injected, it falls under WADA’s S0 rule for drugs with no current human approval anywhere.

Category 2 is FDA’s list of bulk substances that may present significant safety risks in compounding. The 503A bulks list adds substances that pharmacies may compound with. Advisory committee votes are advice; FDA makes the final decision. Sport status follows the WADA Prohibited List in force since January 1, 2026; athletes should confirm with their anti-doping organization. Checked October 5, 2026.

Protocol

Community

Injection: 1–2 mg once daily, or 5 days on and 2 off.

Community

Topical: serums and creams typically run 0.2–2%, applied 1–2× daily.

Frequency: Once daily
Route: Subcutaneous injection (community); topical
Cycle: Injection: about 4–8 weeks on, then 2–4 weeks off; some guides take equal time off to limit copper build-up. Topical: continuous.
6 weeks on, 3 off, shown over 26 weeks

Common protocols

The ways GHK-Cu is most often run, each tagged with where it comes from.

Injection, daily

Community

Dose: 1–2 mg
How often: Once daily (some use 5 days on, 2 off)
How long: About 30 days, then 30 days off

Most cited injected range. One clinic guide starts at 1 mg for 15 days, then 2 mg.

Draw 5–10 units50 mg + 2.5 mL

Topical (studied)

Trial

Dose: Cosmetic cream or serum
How often: Once or twice daily
How long: 8–12 weeks

The form tested in small human skin studies, mostly women with sun-damaged skin. Strength varies by product.

In blends

Community

Dose: 1–2 mg GHK-Cu share
How often: Once daily
How long: 4–8 weeks

How it’s taken in GLOW and KLOW. See those entries.

Taking it

Where it goes

Injection: under the skin of the lower belly, outer thigh or back of the upper arm, spots at least an inch apart. Topical: on clean skin of the face, neck or other treated areas.

If you miss a dose

No published guidance, and the guides checked don’t address it. Skip it and resume the next day; don’t double up. Topical: just apply at the next usual time.

What to expect

12 weeks (topical)
In 71 women, a GHK-Cu face cream increased skin density and thickness and reduced fine lines and wrinkle depth.
Trial
12 weeks (topical)
On thigh skin, collagen improved in 70% of women using GHK-Cu cream vs 50% with vitamin C and 40% with retinoic acid.
Trial
Weeks 3–8 (injected)
Guides for injected GHK-Cu blends describe first skin changes in this window. No human study has tested injection.
Community

Side effects and what to do

Injection-site sting, redness, swelling or bruising (community)

Common. Inject slowly, let the vial reach room temperature, rotate sites. Usually clears in 1–3 days.

Flushing, warmth or metallic taste after injecting (community)

Starts within minutes and fades in 1–2 hours. Some halve the dose if it’s bothersome.

Mild tiredness or headache (community)

Occasional. Stop if it persists.

Topical: mild stinging or redness

Reported with skin products. Apply less often or stop if it lasts.

Copper build-up with long injected use (theoretical)

The main long-term concern in clinic guides. Cycle off, and avoid with Wilson’s disease.

Stop and get medical help

Hives, face or throat swelling or trouble breathing; vomiting, belly pain or yellow skin or eyes (possible copper excess); or spreading redness, heat or pus at a site.

Tracking and pairing

Worth tracking

Injection-site reactions
Copper and zinc levels with long or high-dose injection use (one clinic guide’s advice; no set standard)

Often paired with

BPC-157 + TB-500
Premixed as the GLOW blend for skin plus tissue repair.
KPV
Added to GLOW to make KLOW, for inflammation as well.

Human studies

5 key published human studies, with how many people took part. Animal studies aren’t listed here.

1994

Median closure of plantar ulcers was 98.5% with the gel vs 60.8% with vehicle; ulcer infections were 7% vs 34%.

Design
Multicenter randomized evaluator-blinded vehicle-controlled trial, diabetic foot ulcers
Dose
GHK-Cu gel (Iamin), metered dose applied daily

Mulder et al., Wound Repair Regen 1994, PMID 17147644
200271 people

Reported gains in skin density and thickness and fewer fine lines and wrinkles in women with photoaging.

Design
Conference poster on facial photoaging; design details not published
Dose
GHK-Cu facial cream (strength not reported)
Length
12 weeks

Leyden et al., AAD annual meeting poster 2002, p. 68; cited in Pickart & Margolina, Int J Mol Sci 2018, doi:10.3390/ijms19071987
2016

Wrinkle volume fell 55.8% vs carrier serum and 31.6% vs Matrixyl 3000.

Design
Randomized double-blind trial in women, vs carrier serum and Matrixyl 3000
Dose
GHK-Cu in a nano-lipid carrier serum, twice daily
Length
8 weeks

Badenhorst et al., J Aging Sci 2016, doi:10.4172/2329-8847.1000166
200613 people

No objective difference in redness or wrinkles; patient-rated skin quality was better with GHK-Cu (P = .04).

Design
Randomized trial after CO2 laser resurfacing
Dose
Post-laser skin care regimen with GHK-Cu vs without
Length
12 weeks

Miller et al., Arch Facial Plast Surg 2006, PMID 16847171
1998

Collagen production rose in 70% of women using GHK-Cu cream vs 50% with vitamin C and 40% with tretinoin.

Design
Pilot comparison on thigh skin, GHK-Cu cream vs vitamin C cream vs tretinoin
Dose
Topical cream
Length
12 weeks

Abdulghani et al., Dis Manag Clin Outcomes 1998, doi:10.1016/S1088-3371(98)00011-4

Mixing your vial

Vial	Water	Common dose	Draw	Strength	Action
50 mg	2.5 mL	1 mg	5 units (0.05 mL)	20 mg/mL
100 mg	5 mL	1 mg	5 units (0.05 mL)	20 mg/mL

A faint blue tint is normal; cloudiness isn’t. Add the water slowly down the wall to limit foaming. Stronger solutions sting more.

Dose chart

Syringe units for common doses at different water volumes. Select a cell to open it in the calculator.

Dose	Water added
Dose	1 mL	2 mL	2.5 mL	3 mL
1 mg
1.5 mg
2 mg

U-100 insulin syringe: 100 units is 1 mL. Draws over 100 units show in mL. Faded values are under 2 units, which is hard to measure. Check that your vial holds the larger volumes.

Datasheet

Half-life: No reliable value has been published.
Type: Peptide, 3 amino acids
Molecular weight: 402.9 g/mol
Formula: C₁₄H₂₃CuN₆O₄⁺
Sequence: GHK
Storage before use: Freezer (about −20 °C) for long-term storage.
After mixing or opening: Fridge (2–8 °C); use within about 4 weeks.

Molecule: PubChem CID 71587328 (prezatide copper, copper tripeptide-1); GHK without copper is 340.4 g/mol (CID 73587)
Storage: Community Common practice for research peptides; no approved label exists.

Cautions

No human data for injection.
Avoid with Wilson’s disease or other copper-metabolism disorders.
Injection-site redness and stinging are common; rotate sites.

Questions

What is GHK-Cu?

A naturally occurring copper-binding tripeptide found in human plasma. It is widely used in skin care as copper tripeptide-1.

Is GHK-Cu FDA-approved?

Not approved as a drug in the US or EU; sold as a cosmetic ingredient (INCI name copper tripeptide-1). The nomination for injectable GHK-Cu was withdrawn, so it is no longer in FDA Category 2 (April 2026). Non-injectable GHK-Cu is under evaluation (Category 1), and FDA plans to consult its advisory committee by the end of February 2027.

What is the usual GHK-Cu dose?

From community reports, not established: Injection: 1–2 mg once daily, or 5 days on and 2 off. Topical: serums and creams typically run 0.2–2%, applied 1–2× daily. These are the amounts sources reference, not recommendations.

How much water do I mix GHK-Cu with?

There’s no single right amount, because the water only sets the strength. With 2.5 mL of bacteriostatic water in a 50 mg vial, the strength is 20 mg/mL, so 1 mg is 5 units on a U-100 insulin syringe. More water makes small doses easier to measure. The dose chart above shows other volumes.

How should GHK-Cu be stored?

Before mixing: Freezer (about −20 °C) for long-term storage. After mixing: Fridge (2–8 °C); use within about 4 weeks. This is common practice; no product label covers it.

Is GHK-Cu banned in sport?

Probably. Topical cosmetic use isn’t banned. Injected, it falls under WADA’s S0 rule for drugs with no current human approval anywhere.

Has GHK-Cu been studied in people?

Yes. The human studies section lists 5 published studies. Among them, from 1994: Median closure of plantar ulcers was 98.5% with the gel vs 60.8% with vehicle; ulcer infections were 7% vs 34%.

Sources

Pickart & Margolina, GHK-Cu review (Int J Mol Sci 2018) PMCID PMC6073405

For the protocol details

Pickart & Margolina 2018, GHK-Cu review (Int J Mol Sci)

Doses tagged Community come from public dosing guides and user reports, checked against at least two of them. Those sites aren’t named here because many of them sell peptides or earn commissions on them.

By Vial Guide editorsLast reviewed October 5, 2026

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