GHK-Cu
Also called GHK, copper peptide
GHK-Cu is a copper-carrying peptide your body makes naturally, and it's one of the darlings of skin science.
The published research here is animal and laboratory work. The ranges below come from community-reported dosing and results — what people have settled on in practice, and what they report happening.
12,755 posts20 communities
of community reporting analysed for this compound. That is the part you cannot find anywhere else — the trial data below it, you could look up yourself.
- Longevity & anti-aging
- Recovery & injury
- Skin & hair
The quick answer
GHK-Cu is a copper-carrying peptide your body makes naturally, and it's one of the darlings of skin science. It does two things at once: it delivers copper your skin needs, and it signals your cells to rebuild collagen and elastin - essentially telling older skin to act younger.
This is a slow, cumulative one - think in four-to-eight-week cycles and track it with photos, not feelings. People use it for firmer, smoother skin, faster healing of wounds and scars, and better hair quality. Injection reactions are usually mild, sometimes with a harmless faint blue tint from the copper. Worth knowing: the strongest evidence is for topical use, and anyone with a copper sensitivity should skip it.
Why people use it
✨ Firmer, smoother, younger skin; 🧬 Boosts collagen and elastin; 🩹 Speeds wound and scar healing; 💇 Supports thicker hair; 🛡️ Calms and protects skin
What people report using
These are ranges other people have reported running. They are here so you can see what has actually been done — they are not medical advice and not a recommendation for you.
Longevity & anti-aging
- How often
- Every day, rotate sites
- Route
- subcutaneous
- Where this comes from
- Animal and lab research
Firmer skin, fewer fine lines, better hair and nails, scars softening.
Recovery & injury
- How often
- Every day, rotate sites
- Route
- subcutaneous
- Where this comes from
- Animal and lab research
Firmer skin, fewer fine lines, better hair and nails, scars softening.
Skin & hair
- How often
- Every day, rotate sites
- Route
- subcutaneous
- Where this comes from
- Animal and lab research
Firmer skin, fewer fine lines, better hair and nails, scars softening.
100mg vial + 3ml BAC water = 33.33mg/ml. 1-2mg = 3-6u. Daily or three times a week; rotate sites.
Work out your own units on the reconstitution calculator — the most common serious mistake in this area is arithmetic, not chemistry.
What to expect, and when
- First thing people notice
- Days 1–7 (site reaction)
- When it gets real
- Weeks 2–3 (skin texture)
- Where it peaks
- Weeks 4–8 (collagen, elasticity)
- Patience needed
- Medium - 4–6 weeks
- Days 1–7Barrier feel; possible mild site reaction
Early on, users commonly report improved hydration, softness, and reduced tightness as the skin barrier responds. Some notice transient redness, tingling, or mild irritation at the application site, which typically settles. No structural collagen change is expected this early - this phase is mostly surface feel.
- Weeks 2–3Skin texture & smoothness
Research suggests GHK-Cu upregulates dermal fibroblast activity and signals synthesis of collagen, elastin, and glycosaminoglycans. Around this window users commonly report smoother texture and a more even, refreshed appearance. Visible improvement is gradual rather than dramatic at this stage.
- Weeks 4–8Firmness, elasticity & collagen remodeling
Controlled cosmetic studies over roughly 8–12 weeks reported improved firmness, elasticity, density, and reduced fine lines with twice-daily GHK-Cu formulations. Preliminary comparative work found copper-peptide procollagen responses comparable to or exceeding some reference actives. This is where meaningful, measurable skin changes tend to accumulate.
- Weeks 10–12Peak collagen density on imaging
In a small ultrasound-imaging study, roughly three months of daily GHK-Cu use was associated with an average increase in collagen density, a structural change visible on imaging. Effects depend heavily on formulation, concentration, and consistency of use. Continued application is generally needed to maintain gains.
Most human data come from small cosmetic studies with varied formulations; results depend on product quality, concentration, and consistent use, and individual response varies widely.
Side effects, and what people do about them
Very well tolerated. Injected, you may get some stinging or redness at the site - that is the copper, not a reaction, and it fades once the shot is in. Injecting slowly and rotating sites handles almost all of it. Topically it is gentle, with the odd bit of mild irritation. Because it carries copper, it is used in sensible cycles rather than continuously - an easy thing to plan around.
Go deeper
Open these only if you want them.
How it actually works
A copper-binding tripeptide - glycyl-histidyl-lysine - complexed with a copper ion, and the copper is not incidental. GHK acts as a carrier that delivers copper where it is needed, and the complex modulates gene expression unusually broadly: studies in fibroblasts show hundreds of genes shifted up or down, with net effects on collagen, elastin and glycosaminoglycan synthesis.
For stacking, the thing to know is chemical rather than receptor-based. Applied topically alongside strong acids, high-dose vitamin C or retinoids, the complex can be destabilised - this is the common reason people report it doing nothing. Injected, there is no receptor being competed for.
What people report, in full
Here the community has a clear verdict: topical GHK-Cu is the star, and the injectable version is the underdog. For topical skincare, roughly eight in ten report real wrinkle and skin-quality improvements over two to four weeks - one of the better-validated peptides for skin. The subcutaneous route gets much more mixed reviews, and many people abandon injections for topical serums, questioning why you'd inject something that works so well on the skin. People also flag copper build-up as a reason to be cautious with high-dose injecting.
Worth knowing
This is the normal state of this category and it is not a black mark. It usually means nobody could patent the molecule tightly enough to fund a trial. It is not the same as having been tested and failed.
Sources and review
Most of what is useful about these compounds comes from people who have used them, not from trials. These are published analyses of what communities reported. We did not read the posts ourselves and we do not claim to.
12,755 posts20 communities
Reports from 2023-01-01 to 2024-05-18
Rosenberg AE, et al. Injuries, Injections, and Internet Forums: A Qualitative Study of Reddit User Perspectives on Peptide Therapy After Orthopaedic Surgery. Sports Health 2026;18(4):901-910.
Qualitative coding. No dose distributions reported.
Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. Int J Mol Sci 2018;19(7):1987.Review of gene-expression and regenerative data.
These references were located by literature search and recorded as the primary sources behind this record. The publishers block automated retrieval, so they are pointers to the right papers rather than quotations we have checked line by line. They are replaced as we read them properly.
Last reviewed 2026-09-06.
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