Compound monograph
Melanotan II
Also known as: MT-II, MT-2
§1 Definition
Melanotan II is a synthetic cyclic peptide analog of α-melanocyte-stimulating hormone, developed at the University of Arizona in the late 1980s as a candidate skin-cancer chemopreventive agent. It is not FDA-approved for any use. Small early-phase human trials in the 1990s tested it for tanning and erectile dysfunction; that erectile-dysfunction research later led to the separately-developed, FDA-approved drug bremelanotide (Vyleesi) — a different, related molecule, not Melanotan II itself.
Educational purposes only, not medical advice. Dosing figures below are documented ranges from cited literature, not a recommendation for any individual. Consult a qualified provider before administering anything.
§2 Evidence tier and regulatory status
Evidence tier
3 — Early-phase or limited human data
Early-phase trials, small human studies, or case reports only — not yet late-phase trials.
Not FDA-approved for any use. On August 30, 2007, FDA issued a warning letter to Melanocorp, Inc. (Hendersonville, TN) for marketing Melanotan II as an injectable tanning product with unauthorized disease-prevention claims (skin cancer, rosacea), stating it is an unapproved new drug. This research pass could not locate a live copy of the original warning letter on fda.gov itself (FDA's warning-letter archive did not return it at the URLs tried); the citation below is trade-press reporting of the action rather than the primary FDA document.
§3 Documented dosing
| Context | Range | Frequency | Source |
|---|---|---|---|
| Phase 1 dose-escalation, tanning response (investigational, not a recommended dose) | 0.01–0.03 mg/kg | subcutaneous, weekdays for 2 weeks | [3] |
| Double-blind crossover, erectile dysfunction (investigational, not a recommended dose) | 0.025–0.025 mg/kg | single subcutaneous dose | [4] |
Both ranges above are investigational trial doses from small 1990s Phase 1 studies, not an approved or recommended human dose — Melanotan II has never been reviewed or approved by FDA for any use.
§4 Reconstitution math
No FDA-approved product exists, so no FDA-labeled reconstitution protocol exists either. General lyophilized-peptide reconstitution practice is commonly applied by research/self-administering users, but this is not backed by a compound-specific clinical or regulatory source.
| Vial | Water | Concentration | Draw volume | Units (U-100) |
|---|---|---|---|---|
| 10 mg | 2.0 mL | 5000 mcg/mL | 0 mL | 0.0 |
- Concentration
- 5000 mcg/mL
- Draw volume
- 0 mL
- Syringe units
- 0.0
- Doses per vial
- 1000000
- Draws below 2 units have low measurement precision on a standard syringe. Consider adjusting the water volume via the reverse solver.
Suggested adjustment: 20000 mL of water would bring this dose to a 2-unit draw.
§5 What the research shows
| Trial | Phase | n | Duration | Endpoint | Result | Source |
|---|---|---|---|---|---|---|
| Phase 1 pilot dose-escalation study | Phase 1 | 3 | 2 weeks (escalating subcutaneous doses, weekdays) | Tanning response and dose-limiting toxicity in healthy male volunteers | Dose-dependent tanning was confirmed in all 3 subjects. Dose-limiting adverse effects included nausea, flushing, and spontaneous penile erections. | [3] |
| Double-blind, placebo-controlled crossover study | Phase 1/2, human | 10 | Single-dose crossover | Erectile response in men with psychogenic erectile dysfunction | Clinically apparent erections occurred in 8 of 10 subjects on active drug. Mean tip-rigidity duration exceeded 80% for 38.0 minutes, versus 3.0 minutes on placebo. | [4] |
§6 Safety and reported adverse effects
| Effect | Incidence | Source |
|---|---|---|
| Nausea | — | [3] |
| Flushing | — | [3] |
| Spontaneous penile erections | — | [3] |
| New or changing moles / melanoma (case report) | — | [5] |
The melanoma association is case-report-level evidence, not established causation: one published case report describes melanoma diagnosed in a 20-year-old woman after a 3-4 week course of self-injected Melanotan II, but multiple sources note that conclusive causal evidence linking Melanotan II to melanoma is lacking. This is included because it is a real, published safety signal that a reader should know about — not because a causal relationship has been proven. No systematic incidence data exists for any of the effects listed above; they are individual reported findings, not population-level rates.
Contraindications
- No published data located from a controlled trial — FDA's warning letter states there is no evidence of safety or efficacy for its marketed (tanning) use.
Known interactions
- No published data located.
§7 Storage and handling
- Lyophilized
- No published data located.
- Reconstituted
- No published data located.
§8 Sourcing considerations
- Melanotan II is not FDA-approved and is the subject of an explicit FDA warning letter regarding unauthorized marketing claims — verify independent third-party testing (COA) for any product sold as Melanotan II.
- Be aware of documented case reports of new or changing moles associated with unregulated injectable tanning products; a dermatologic exam before and after any use is a reasonable precaution.
- Confirm the product is not being confused with or substituted for bremelanotide (Vyleesi), a different, FDA-approved molecule with a different indication.
§9 FAQ
What is Melanotan II?
A synthetic peptide analog of alpha-melanocyte-stimulating hormone, originally researched as a tanning agent and skin-cancer chemopreventive. It is not FDA-approved for any use.
Is Melanotan II FDA approved?
No. FDA issued a warning letter in 2007 to a company marketing it as an injectable tanning product, stating it is an unapproved new drug with unauthorized disease-prevention claims.
Is Melanotan II the same as PT-141 / bremelanotide?
No, though they're related. Bremelanotide (Vyleesi) was developed from the same line of research and is FDA-approved for a specific indication in women, but it is a different, separately-approved molecule from Melanotan II.
Does Melanotan II cause melanoma?
This is not established. A single published case report describes melanoma in a young woman following self-injection, but this is case-report-level evidence, not proof of causation.
Has Melanotan II been tested in humans?
Yes — small Phase 1 human trials in the 1990s (3 subjects for tanning response, 10 subjects for erectile dysfunction) found dose-dependent effects, but no large-scale or FDA-reviewed trials have been conducted.
What are Melanotan II's side effects?
Reported effects from small trials include nausea, flushing, and spontaneous erections. See the safety section above for the important caveat about the melanoma case report.
§10 Sources
- [1] FDA Issues Warning Letter for Injectable Tan Product (Melanocorp, Inc.). Cosmetics & Toiletries (reporting FDA action), 2007. Other. https://www.cosmeticsandtoiletries.com/regulations/regional/news/21845546/fda-issues-warning-letter-for-injectable-tan-product
- [2] melanotan-II, CID 92432. PubChem, National Library of Medicine (NIH), 2026. Other. https://pubchem.ncbi.nlm.nih.gov/compound/melanotan-II
- [3] Evaluation of Melanotan-II, a Superpotent Cyclic Melanotropic Peptide in a Pilot Phase-I Clinical Study. Life Sciences, 1996. Peer-reviewed. https://pubmed.ncbi.nlm.nih.gov/8637402/
- [4] Synthetic Melanotropic Peptide Initiates Erections in Men with Psychogenic Erectile Dysfunction: Double-Blind, Placebo Controlled Crossover Study. Journal of Urology, 1998. Peer-reviewed. https://www.auajournals.org/doi/abs/10.1016/S0022-5347%2801%2962903-3
- [5] Melanoma Associated with the Use of Melanotan-II. Dermatology (Karger), 2014. Peer-reviewed. https://karger.com/drm/article/228/1/34/114247/Melanoma-Associated-with-the-Use-of-Melanotan-II