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PEPTIDESUNCENSORED

GHK-Cu

/G · H · K copper/aka Copper peptide, Copper tripeptide-1, Glycyl-L-histidyl-L-lysine copper

A three-amino-acid peptide that carries copper and, in lab studies, pushes skin cells toward collagen production and tissue remodeling.

TopicalSubcutaneousDaily
Open in cycle visualizer

GHK-Cu: educational research discussion. Not medical advice. Not a protocol for you.Details

Reported range
1–2 mg (injectable)
Frequency
Daily in most discussions
Cycle length
Short blocks; topical studies ran 8–12 weeks
Half-life
Unknown in humans
Route
Topical or SC

Reported figures describe what is published or discussed. None of them is a dose for you.

Mechanism

What it is proposed to do

GHK (glycyl-L-histidyl-L-lysine) binds copper(II) tightly and was first isolated from human plasma by Loren Pickart in 1973. Reported plasma levels fall from about 200 ng/mL at age 20 to about 80 ng/mL at age 60. In cell and wound models, GHK-Cu increases collagen, decorin and glycosaminoglycan production, shifts the activity of matrix-remodeling enzymes, and changes the expression of many genes. Whether injected GHK-Cu does any of this in people is untested.

  1. 01

    GHK-Cu

    Tripeptide carrying one copper ion; occurs naturally in plasma

    established
  2. 02

    Copper delivery to cells

    Shown in lab studies

    proposed
  3. 03

    Collagen · matrix remodeling

    Fibroblast collagen, decorin and GAG synthesis in cell and wound models

    proposed
  4. 04

    Skin appearance changes

    Small topical studies; objective results mixed

    proposed
EstablishedProposed from animal or cell data

Half-life. Poorly characterized. No published human pharmacokinetic study of injected GHK-Cu.

Dosing & cycles

What is reported, and where it comes from

Numbers below are labeled FDA label, clinical trial range or commonly reported range. They describe the published and discussed landscape. They are not instructions and not a protocol for you.

Dosing studio

Every figure is labeled by where it comes from.

This is not your dose

Scale view: Commonly reported injectable range

0
0.5
1
1.5
2
2.5
3

Probe at 1.5 mg: inside the reported band (1–2 mg). Drag it to read the scale. It does not pick a number for you.

Typical cycle, as a calendar

Community injectable block

A few weeks on, then a break

Daily injections for a short block, then time off. Block and break lengths are convention, not GHK-Cu data.

OffLow / startMid / loadingHigh / maintenance

Cycle patterns

Community injectable block

A few weeks on, then a break

Daily injections for a short block, then time off. Block and break lengths are convention, not GHK-Cu data.

On · daily
Break
Week 1Week 8

Topical study pattern

8–12 weeks, continuous

Cosmetic studies applied GHK-Cu products continuously and measured skin changes at 8 to 12 weeks.

Topical · continuous
Week 1Week 12

Stacks

What it gets combined with

Why people pair things, and what nobody has tested.

Pre-mixed repair blends

3 compounds
GHK-CuBPC-157TB-500
Why people combine these
Research-market blends put GHK-Cu in one vial with BPC-157 and TB-500, pitched at skin and soft-tissue repair.
Caution
Fixed ratios nobody tested, three unverified ingredients, and no way to tell which one caused a reaction.
What is unknown
No published human data on this combination: dosing, interactions and long-term effects are all unstudied.

Also sold in pre-mixed blends

What a blend changes

In a blend, GHK-Cu cannot be adjusted on its own, and the mixture has no human data of its own. Typical vial formats shown; labels vary.

Evidence

How much of this is known

Evidence grade

C

Thin human data

Human data thin (pilots, uncontrolled, or none completed). Strong animal data and a lot of anecdote.

How we grade

One grade, two very different evidence bases. Topical cosmetic data are small and often industry-linked. Injectable human data are essentially absent, which on its own would rate a D.

Human trial status

Topical: cosmetic studies summarized by Pickart and colleagues report better skin density, fine lines and firmness over 8–12 weeks, including a 71-woman facial cream study and a 41-woman eye cream study. Many were industry-linked. An independent randomized trial after CO2 laser resurfacing (13 patients) found no objective improvement, only higher patient satisfaction. A 1994 topical trial in diabetic ulcers reported enhanced healing. Injectable: no published human trials.

Limitations

  • Topical and injected GHK-Cu are different exposures. Skin studies say nothing about injection.
  • Much of the review literature comes from one research group.
  • Cosmetic studies are small, short, and rarely independently replicated.
  • The age-related fall in plasma GHK is a correlation. It does not show that replacing it does anything.

Sources to read

Links open PubMed, DailyMed, FDA or trial-registry searches. We do not cite what we have not described accurately.

Safety

Side effects, cautions, status

Commonly reported effects

  • Injectable: stinging or irritation at the injection site is a common anecdotal complaint.
  • Topical: occasional irritation or redness, as with many cosmetic actives.
  • Each dose carries copper. Repeated injection has not been studied for its effect on copper balance.
  • Product quality is the main practical risk for injectables: purity, copper ratio, sterility and endotoxin vary.
Injection-site reactionsUnknown long-term profile

Who should be extra cautious

  • Wilson disease or other copper disorders. Any added copper is a concern when copper clearance is impaired. No data on GHK-Cu in these conditions.
  • Pregnancy or breastfeeding. No data for injectable use. Topical studies did not cover pregnancy.
  • Active or past cancer. Tissue-remodeling and growth signaling are theoretical concerns. No human data either way.
  • Gray-market injectable product. Cosmetic-grade GHK-Cu is not made to injectable standards. Purity, sterility and endotoxin are unverified.
  • Tested athletes. Not named by WADA, but the status of injectable research-market product is unsettled. Confirm with your federation.

Legal & regulatory status

Legal as a cosmetic ingredient in topical skin products. Not an approved drug in the US. In April 2026 FDA removed injectable GHK-Cu from its Category 2 compounding-risk list, which did not authorize compounding. It faces a separate FDA advisory committee review expected before February 2027.

2026 compounding context. Injectable GHK-Cu was among the 12 peptides FDA removed from Category 2 on April 15, 2026. It was not on the July 2026 advisory committee agenda. A separate review is expected before February 2027, and any addition to the 503A bulks list would still need FDA rulemaking.

WADA. Not named on the list. USADA's 2026 cosmetics guidance lists GHK (tripeptide-1) among peptide ingredients that are not prohibited, and says route of use does not change a substance's status. Some anti-doping commentators still flag research-market injectable GHK-Cu as a possible S0 (non-approved substance) issue. Check Global DRO and confirm with your federation.

Storage & handling, high level

Topical products follow their cosmetic packaging. Research-market injectable GHK-Cu is sold as a blue powder, the color coming from copper. Reconstituted peptides are generally kept refrigerated, away from light, and degrade over weeks.

Reconstitution and injection technique are clinical skills. The reconstitution calculator does arithmetic only.

FAQ

Questions people ask about GHK-Cu

Is topical GHK-Cu the same as injectable?
No. Topical GHK-Cu is a cosmetic ingredient with small skin studies behind it. Injectable GHK-Cu is a research-market product with no human trials. Same molecule, different route, different evidence.
Does GHK really decline with age?
Reported plasma levels fall from about 200 ng/mL at age 20 to about 80 ng/mL at 60. That is a correlation. Nobody has shown that raising levels by injection changes how skin or tissue ages.
Is injectable GHK-Cu legal to compound now?
Not as of our last review. FDA removed injectable GHK-Cu from Category 2 in April 2026, which did not authorize compounding. It faces a separate advisory committee review expected before February 2027, and then rulemaking.
Is the copper a problem?
Topical studies have not reported copper-related problems, but they were small. Repeated injection is a different exposure that has not been studied. People with copper-handling disorders such as Wilson disease have the most reason for concern.
Why is it blue?
Copper(II) complexes are blue. The color says copper is present. It says nothing about purity or dose.

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