Head to head
GHK-Cu vs Melanotan II
Side-by-side on skin and hair, dosing, kinetics and evidence — with an honest verdict at the end.
Verdict
No winner in this data
What you are actually choosing between
Both are classed here as cosmetic compounds, so this is a within-class choice: the mechanism is broadly shared and what separates them is kinetics, route, and how much has actually been tested.
The overlap is skin and hair. On this site's goal weighting — an editorial priority score, not a measure of effect size — GHK-Cu rates 5/5 for skin and hair and Melanotan II rates 4/5. Outside that overlap they diverge: GHK-Cu also carries weight for inflammation, injury repair, and longevity, Melanotan II for sexual function.
The evidence
Neither has an evidence edge — both sit at the same tier. GHK-Cu: some human data, but it is small, old, or uncontrolled; the human studies are topical; injectable use rests on animal data. Melanotan II: some human data, but it is small, old, or uncontrolled; it never completed phase 3; supply is grey-market and unverified. Anyone telling you one is clearly better supported than the other is going beyond what is published.
How they differ in practice
GHK-Cu is a subcutaneous injection and applied to the skin; Melanotan II is a subcutaneous injection and a nasal spray. Neither one forces you onto a needle.
No half-life is published for either compound in this dataset. That absence is itself information: it means the pharmacokinetics have not been characterized well enough to quote, so both dosing schedules — once daily for GHK-Cu, once daily for Melanotan II — are convention.
Risk and difficulty
The contraindication lists are not the same: Melanotan II flags under 18, which GHK-Cu does not. If any of those describe you they remove a compound from consideration outright, regardless of everything above.
GHK-Cu is rated intermediate here and Melanotan II advanced. That rating is about how much can go wrong in handling, dosing and monitoring, not about how well either works.
Source notes
What the evidence actually says
Verbatim, so you can check the verdict above against what it was built from.
GHK-Cu
Human evidence is mostly small cosmetic studies of topical formulations at roughly 0.05-2% concentration for skin appearance and hair. Systemic injectable use is supported by animal wound-healing data only, and the 1-2 mg daily figures come from community protocols rather than controlled trials. Cycle it rather than running it continuously because of copper load.
Melanotan II
Melanotan II is a non-selective melanocortin receptor agonist that drives melanogenesis. It is NOT approved as a medicine in any country. It never completed phase 3 development, the FDA has issued warning letters over its sale, and everything available is unlicensed research-chemical or grey-market product of unverified purity and dose. There is no approved label to anchor dosing to, so the numbers here describe common community practice only: roughly 250 mcg daily as a loading phase until the desired pigmentation is reached (commonly 1-4 weeks), then 500-1000 mcg once or twice weekly as maintenance. The stored daily frequency reflects that loading phase; step down once you stop the load. Reported half-life figures in the literature conflict badly (from about half an hour to several hours) and no regulatory pharmacokinetic package exists, so none is listed. THE MELANOMA CONCERN IS THE HEADLINE, NOT A FOOTNOTE. Dermatology case series and case reports describe eruptive melanocytic naevi, rapid darkening and dermoscopic change in existing moles, atypical/dysplastic naevi, and melanoma including melanoma in situ associated with Melanotan use. A personal or family history of melanoma, dysplastic or atypical naevi, or many moles is a conventional reason not to use it at all - that is what the active-malignancy flag on this entry is standing in for, since the dataset has no melanoma-specific flag. Anyone using it should have a full skin check by a dermatologist before starting and be monitored during and after. It does not remove the need for sun protection, and it is frequently combined with sunbeds, which compounds the risk.
Side by side
The numbers
| Attribute | GHK-Cu | Melanotan II |
|---|---|---|
| Class | Cosmetic | Cosmetic |
| Routes | Subcutaneous, Topical | Subcutaneous, Intranasal |
| Dose range | 1 mg–2 mg (typical 1.5 mg) | 250 mcg–1 mg (typical 250 mcg) |
| Frequency | Once daily | Once daily |
| Half-life | Not characterized | Not characterized |
| Cycle length | 4 weeks | 4 weeks |
| Experience | Intermediate | Advanced |
| Evidence | Limited human data | Limited human data |
| Contraindications |
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| Side effects |
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Turn a typical dose into a mark on the syringe: GHK-CuMelanotan II
Goals
Where they overlap, and where they do not
| Goal | GHK-Cu | Melanotan II |
|---|---|---|
| skin and hair | GHK-Cu: 5/5 | Melanotan II: 4/5 |
| inflammationone only | GHK-Cu: 3/5 | Melanotan II: — |
| injury repairone only | GHK-Cu: 3/5 | Melanotan II: — |
| longevityone only | GHK-Cu: 3/5 | Melanotan II: — |
| sexual functionone only | GHK-Cu: — | Melanotan II: 3/5 |
| joint and tendon healthone only | GHK-Cu: 2/5 | Melanotan II: — |
They overlap on 1 goal and diverge on 5. Weights are this site’s editorial priority score out of 5 — how central a goal is to why people use a compound. They are not effect sizes and two 5s do not mean two equal results.
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Educational information only, not medical advice. Talk to a licensed clinician before starting, changing, or stopping anything.