Melanotan II
Aliases: MT-2 · MT-II · MT-2 Acetate · Melanotan 2
Last verified: 2026-09-23
The short version
Melanotan-2 is a 'tanning peptide' with a complicated profile: gray use for skin darkening is global, and the official regulatory picture is negative — regulators have warned about its sale multiple times. Side effects are well documented in case reports: nausea, flushing, increased pigmentation (including unwanted), and the melanocortin pathway has theoretical links to melanoma. No controlled data on benefit exist.
Identity & type
- Molecular type
- analog
- Sequence / structure
- Ciklični heptapeptid (Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-NH2)
- Molecular weight
- ~1024 Da
- Origin
- Synthetic analog of alpha-MSH that stimulates melanocortin receptors.
Mechanism of action
Melanocortin receptor agonist: MC1R (pigmentation), MC3R/MC4R (appetite, sexual function, energy balance).
not confirmed in humans
Dosing & routes
Official / clinical context
Development was abandoned; no active regulatory document exists. There are no official indications.
Regulator-approved labeling and published study designs — never a recommendation.
Community-reported practice
Gray market: 250–500 mcg SC daily until desired tone, then 1–2× weekly maintenance. The community reports fast tanning, strong libido/erection increase, reduced appetite — but also nausea, flushing and darkened moles. The most popular "cosmetic" peptide.
Unverified self-reports. Not medical advice. Not endorsement.
Expected effects (community)
The community reports fast tanning, strong libido/erection increase, reduced appetite — but also nausea, flushing and darkened moles. The most popular "cosmetic" peptide.
Protocol — official vs community
Official / label
No approved product anywhere. FDA warning letters target injectable tanning products containing MT-II.
Duration: —
The regulatory record is a list of enforcement actions, not a dosing literature.
Community (anecdotal)
0.5–1 mg SC 2–3× weekly until desired pigmentation, then 0.5–1 mg weekly maintenance. Often micro-dosed (250–500 mcg) for 'glow' without nausea.
- Cycle:
- 2–4 weeks loading, indefinite maintenance.
- Break:
- None — which is precisely the problem: chronic non-selective melanocortin agonism with no safety data.
Documented: nevus darkening, nausea, flushing, BP effects. Unresolved: long-term melanoma signal. Chronic use is an unmonitored experiment.
Human evidence
No controlled trials for tanning; only case reports of adverse effects and gray-market analyses.
Preclinical evidence
Phase I/II in early 2000s (University of Arizona); halted over side effects, focus moved to Bremelanotide (PT-141).
Known risks
- Nausea, flushing, somnolence (very common on first use)characterized
- Uneven/unexpected pigmentation (melanosis, darkening of eyes)characterized
- Theoretical melanocortin-pathway link to melanomatheoretical
- Regulatory warnings (FDA, TGA et al.) on sale and usecharacterized
Teal: characterized in clinical/labeling contexts. Amber: theoretical or reported outside controlled settings.
Unknowns & evidence gaps
- Cancer risk of chronic melanogenesis stimulation
- Pharmacokinetics and purity of gray products
Frequently asked questions
References
- Regulatory warnings on melanotan products (FDA safety communication)
- Case reports on melanotan-2 adverse effects