GHK-Cu
Copper peptideCopper tripeptide-1Gly-His-Lys copperEvidence
Preclinical
Half-life
1 h
Typical vial
50 mg
Route
2 routes
What it is
A naturally occurring copper-binding tripeptide with a long history in topical skincare research. Injected use is not what the research studied.
GHK is a three-amino-acid sequence, glycine-histidine-lysine, that occurs naturally in human plasma and binds copper with high affinity. The copper complex, GHK-Cu, has been studied since the 1970s, which makes it unusual in this category: there is a real, decades-long literature behind it.
The important qualifier is route. Most of that literature concerns topical application to skin, or laboratory work on cultured cells. It is used as a cosmetic ingredient in products sold legally worldwide. The injected use discussed in peptide communities is a different proposition, and the topical and cell-culture research does not transfer to it automatically.
It is also the component that gives GLOW and KLOW blends their characteristic blue colour, and typically the largest component by mass in those vials. Anyone dosing a blend by its BPC-157 content is taking considerably more GHK-Cu than they may realise.
How it works
GHK binds copper and appears to act as a carrier that delivers it to tissue. Copper is a required cofactor for lysyl oxidase, the enzyme that cross-links collagen and elastin, which is the most direct link between this peptide and the skin-remodelling effects reported for it.
Gene expression work in cultured cells has reported that GHK influences a large number of genes involved in tissue remodelling and inflammation. Those studies are in vitro; what a given dose does in a living person, by any route, is a separate question that the cell work does not answer.
What it is studied for
Each entry states the evidence behind it. We do not rank indications by effectiveness — for most compounds here, that would be a claim nobody can support.
Skin remodelling and appearance
Published reviewThe best-supported use, and the one the research base actually covers.
EvidenceHuman topical studies and cosmetic use. Applied to skin, not injected.
Wound healing
Published reviewStudied for effects on dermal repair.
EvidenceAnimal and in vitro models, largely topical application.
Hair growth
Published reviewUsed in topical hair products.
EvidenceLimited human topical data.
Regulatory status
Last reviewed 12 Aug 2026. Positions in this category change frequently, so we date the line.
Permitted as a topical cosmetic ingredient in the United States and widely sold as such. Not approved as an injectable medicine, and injectable material is a research chemical with no manufacturing standard behind it.
Identity and clearance
What the molecule is, and how long a dose stays measurable.
Molecule
- Class
- Tripeptide-copper complex
- Molecular weight
- 340.4 Da
- Length
- 3 amino acids
Sequence
Gly-His-Lys (copper complex)
The copper ion is part of the active molecule, not an additive. This is also why solutions are blue.
Pharmacokinetics
Published reviewPlasma GHK declines markedly with age. No pharmacokinetic study of injected GHK-Cu at community doses has been published.
Dose protocols reported in sources
Displayed for reference only. Every row says where it came from, and a trial protocol and a community convention are not the same kind of information. None of this is fed into the calculator, and none of it is a recommendation.
A week-by-week progression is also reported for GHK-Cu. See it against a 50 mg vial, where the syringe units can be worked out.
| Goal | Dose | Frequency | Route | Units, 50 mg vial | Source | Start this protocol |
|---|---|---|---|---|---|---|
| Commonly described injected dose | 1 mg – 2 mg | Once daily | Subcutaneous | 10–20 u | Community practice | Start this |
| As delivered within a GLOW or KLOW blend | 1.25 mg – 2 mg | Once daily | SubcutaneousIn a blend this is not chosen independently. It follows from the ratio in the vial and the dose you pick for whichever component you are dosing by. | 12.5–20 u | Community practice | Start this |
The doses above in syringe units, for the vial you have:
Start this copies a row into a protocol of your own, which you can then edit. Where a source gave a dose range or an ambiguous frequency, those fields arrive empty — we will not pick a number on your behalf.
CheckRows marked community practice describe what people commonly do, drawn from public discussion. They are not derived from any trial and are not evidence that a dose is safe or effective.
Cycling
Community practice4 to 6 weeks on, 2 to 4 weeks off.
A community convention. Copper accumulation is the usual stated reason for taking breaks, though no study establishes a threshold at these doses.
Work out what to draw
Pre-filled with a 50 mg vial as a worked example. These are not recommended values — change them to match the vial in front of you.
Draw to 12.5 units on a 1 mL U-100 syringe. That is 0.125 mL, containing 1.25 mg of GHK-Cu.
Check12.5 units falls between the printed lines on a 1 mL U-100 syringe. Mixing with 4.8 mL of water instead would put this dose at 12 units.
BioAlmanac performs arithmetic on values you enter. It does not recommend doses, schedules or compounds, and nothing here is medical advice. Confirm every calculation against your vial and syringe before drawing, and speak with a licensed healthcare provider.
Open this calculation in the full calculator
Units, concentration, bacteriostatic water — the glossary defines the vocabulary, and a unit is not a fixed volume.
Safety
Reported effects, the situations that need care, and the ones that mean stop.
Reported effects
- Injection site stinging, redness or irritationCommunity practice
Commonly reported
Reported more often than with most peptides in this category.
- Temporary blue discolouration at the injection siteCommunity practice
Occasionally reported
The compound is blue; this is cosmetic, not a sign of harm.
- Nausea or headacheCommunity practice
Occasionally reported
- Effects of sustained copper loadingCommunity practice
Unknown
Injecting a copper complex daily delivers copper. Whether that matters at these doses has not been studied.
When to stop
- Signs of infection at an injection site: spreading redness, warmth, swelling, pus, or fever.
- Any allergic response: rash, hives, facial swelling, or difficulty breathing. Seek urgent care.
- Persistent nausea, abdominal pain or fatigue, which are among the features of copper excess.
- Injection site reactions that intensify with each dose.
Interactions and situations that need care
- Wilson's disease or any copper metabolism disorderAvoid
Wilson's disease is a genetic inability to clear copper properly. Deliberately injecting a copper-carrying compound is directly contrary to its management.
- Copper supplementationUse caution
GHK-Cu delivers copper. Taking it alongside a copper supplement stacks the same input from two directions without either source accounting for the other.
- Pregnancy and breastfeedingAvoid
No reproductive or developmental safety data for injected use.
- Active or previous cancerUse caution
Copper is involved in angiogenesis, and copper-lowering has itself been investigated as an anti-cancer strategy. No study has examined injected GHK-Cu in people with cancer.
What to expect
What the sources describe over time, and how confident anyone can be about it.
HonestlyThere is no human efficacy data for this compound, so there is no evidence-based timeline to give. Any site publishing a week-by-week schedule of expected effects has invented it.
- Human evidence for GHK-Cu is topical. If you are injecting it, the studies most often cited in support are not studies of what you are doing.
- Skin changes reported in topical studies developed over weeks to months of consistent application.
- The blue colour of the solution and any temporary tint at the injection site are expected properties of a copper complex, not signs of anything going wrong.
Storage and combinations
How to keep it, and what it does and does not go with.
Storage and handling
- Freeze-dried powder
- Refrigerated at 2–8 °C, protected from light.
- After mixing
- Refrigerated at 2–8 °C. The solution is characteristically blue; that colour is expected and is not a fault.
- Long-term, frozen
- Unopened powder is stable at −20 °C or colder.
With other peptides
- AHK-Cucaution
Both deliver copper into tissue, and using them together means doing that by two routes at once. This is the copper peptide with the actual dermatological research behind it.
Stacks with GHK-Cu in them
Documented combinations and plans people have published, with full schedules.
Documented combinations, with full schedules.
Published by people running it. Their plans, not ours — one person doing something is not evidence that it works.
Checking your vial
Research chemicals carry no manufacturing standard, so what the vial looks like is often the only quality signal available before you use it.
Blue powder, blue solution
The copper complex is blue. A GHK-Cu vial that is not blue once mixed is not GHK-Cu.
Colourless after mixing
Suggests the material is not the copper complex it was sold as.
Cloudy or particulate
Indicates degraded or contaminated material.
Vocabulary on this page
- Bioavailability
- How much of an administered dose actually reaches the bloodstream. Injection is close to complete; swallowing a peptide is usually close to nothing.
- Blend
- One vial containing several peptides at a fixed ratio, reconstituted and drawn together.
- Vial
- The small sealed glass container a peptide is sold in, holding a stated mass of freeze-dried powder under a rubber stopper.
- Stack
- Several separate compounds run at the same time, each in its own vial and on its own schedule.
- Injection site
- Where on the body an injection is given. Rotating between sites is standard practice for anything given repeatedly.
- Peptide
- A short chain of amino acids: the same building blocks as a protein, in a chain short enough to behave differently.
Questions
- Why is my GHK-Cu solution blue?
- Because it is a copper complex, and copper complexes of this kind are blue. A vial that mixes to a colourless solution is unlikely to be what it was sold as.
- Is the topical research relevant to injecting it?
- Not directly. The large majority of GHK-Cu research concerns topical application to skin or laboratory work on cultured cells. Injected use at community doses has not been studied, and it is a different exposure entirely.
- How much GHK-Cu is in a GLOW blend?
- In a typical 70 mg GLOW vial, 50 mg is GHK-Cu. Five times the amount of either other component. Someone dosing that blend by its BPC-157 content is taking five times as much GHK-Cu as BPC-157 with every draw.
References
Everything on this page that came from a source, with the source.
The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline
Brain Sciences, 2017 · Review of gene expression and preclinical work
Cultured human cells and animal models
Reviews reported effects of GHK on genes involved in tissue remodelling, inflammation and repair, and summarises the topical and in vitro literature.
10.3390/brainsci7020020
Commonly reported community protocols
BioAlmanac editorial summary of public community sources, 2026 · Not a study
Summarises the injected dose ranges most consistently described in public discussion. Carries no evidential weight about safety or effect.
Compiled community protocols
BioAlmanac editorial summary of a public protocol compilation, 2026 · Not a study
Records a week-by-week progression described on a vendor-adjacent protocol site, retrieved August 2026. Only the doses are taken from it. Its own syringe-unit conversions were checked against the vial sizes it states and several understate the volume by half, so nothing computed by that source is reproduced here — the units on this site are worked out from the vial in front of you. Carries no evidential weight about safety or effect.
Related compounds
AHK-Cu
GHK-Cu's less-studied sibling, used topically for hair. Almost all the research people cite for it is actually GHK-Cu research.
BPC-157
A synthetic 15-amino-acid peptide studied in animals for effects on tendon, ligament and gut tissue repair. No completed human trials.
TB-500
A synthetic fragment of thymosin beta-4, a naturally occurring protein involved in cell migration and tissue repair. Animal evidence only.
KPV
A three-amino-acid fragment of alpha-MSH studied for anti-inflammatory effects, largely in animal models of gut inflammation.
Next
What to do with GHK-Cu
- Keep a record of itTurn a dose and a schedule into a protocol, then log what you actually take. GHK-Cu is filled in for you.
- See what it costsPer-milligram prices read from vendor sites and confirmed by a person, so vial sizes compare.
- Check a combinationWhat our profiles record about GHK-Cu alongside each other compound — including the pairs where nothing is recorded.
Keep this page honest
If something here is wrong, out of date, or missing a source, tell us and we will fix it and say that we did.
This page is educational. It describes what published research reports, not what you should do. Peptides discussed here are largely not approved for human use, and nothing on BioAlmanac is medical advice. No clinician reviews these pages.
Page last updated 12 Aug 2026