Synthetic alpha-MSH analog researched for skin pigmentation (tanning), photoprotection, and sexual function enhancement.
Last Updated: May 2026
Melanotan II (MT-2) is a synthetic cyclic α-MSH analog with broader melanocortin receptor binding than Melanotan I, producing skin pigmentation, sexual function effects, and appetite suppression through engagement of multiple melanocortin receptors. It is the parent compound from which PT-141 (bremelanotide) was derived as the FDA-approved selective MC4R agonist for sexual desire disorder. Important regulatory update: Melanotan II was removed from the FDA's Category 2 bulk substances list on April 22, 2026 and is scheduled for PCAC review in early 2027.
Melanotan II is a synthetic cyclic 7-amino-acid α-MSH analog (cyclic via lactam bridge) that binds multiple melanocortin receptors: MC1R (melanocyte pigmentation), MC3R (energy homeostasis), MC4R (sexual function, appetite), and MC5R (exocrine function). The broad receptor engagement produces multiple effects including skin pigmentation, sexual arousal, appetite suppression, and occasional nausea/flushing. The cyclic structure differentiates MT-2 from the linear Melanotan I. Evidence level: Preclinical extensive; community/cosmetic use extensive; PT-141 (MT-2-derived) FDA-approved.
Preclinical studies have demonstrated the broad melanocortin receptor effects across pigmentation, sexual function, and appetite. Phase 2 human trials by Palatin Technologies explored MT-2 derivatives — leading to the development and FDA approval of PT-141 (Bremelanotide, Vyleesi) as a selective MC4R agonist for hypoactive sexual desire disorder. Melanotan II itself has not advanced to formal regulatory approval; it remains widely used in community and cosmetic contexts. Evidence level: Preclinical extensive; community/cosmetic use; MT-2-derived PT-141 FDA-approved.
Melanotan II is the broad-receptor cyclic analog from which the selective MC4R agonist PT-141 was derived; it differs from Melanotan I by cyclic structure and broader receptor binding.
| Compound | Structure | Receptor binding | FDA/regulatory status |
|---|---|---|---|
| Melanotan I | 13-AA linear | MC1R selective | EMA-approved (EPP) |
| Melanotan II (MT-2) | 7-AA cyclic | MC1R + MC3R + MC4R + MC5R | Not approved |
| PT-141 | MT-2 metabolite | MC4R primary | FDA-approved (Vyleesi, HSDD) |
Common side effects in community use include nausea, flushing, mild hypertension, and occasional spontaneous penile erection (a melanocortin pathway effect). The broad receptor binding produces a more variable side effect profile than the selective MC4R agonist PT-141. Melanoma risk is a theoretical concern given melanocyte stimulation, with case reports of new or changing nevi documented in community use. Long-term safety at sustained dosing is not characterized at Western RCT standards. Evidence level: Community use safety reports; case reports of melanocyte concerns; long-term unestablished.
Melanotan II is not approved for any medical or cosmetic indication anywhere in the world as of May 2026. On April 22, 2026, Melanotan II was removed from the FDA's Category 2 bulk substances list and is scheduled for Pharmacy Compounding Advisory Committee (PCAC) review in early 2027. Removal from Category 2 does not authorize compounding pharmacy production. Current status in FDA peptide regulation 2025–2026 timeline.
Melanotan II is widely sold in research-grade markets but with substantial quality variance and occasional mislabeling — including substitution with the related but distinct PT-141. Mass spectrometry identity confirmation distinguishes the two. Independent HPLC purity testing is the standard quality signal. Guidance in how-to-test-peptides hub.
Peptigrity purchases Melanotan II vials anonymously at standard customer pricing, sends them to ISO-accredited third-party labs for HPLC and mass spectrometry analysis, and publishes the unedited certificate of analysis. Methodology in how we calculate trust scores.
Melanotan II binds multiple melanocortin receptors producing skin pigmentation, sexual function effects (including spontaneous erection in some users), and appetite suppression. The broad receptor engagement produces a complex effect profile.
Melanotan II is legal to purchase as a research chemical for laboratory use in most jurisdictions, but it is not approved for human consumption. The April 22, 2026 Category 2 removal opens a potential future compounding pathway pending PCAC review in early 2027. Country breakdown in peptide legal status guide.
Melanotan II is scheduled for Pharmacy Compounding Advisory Committee (PCAC) review in early 2027. Track developments in FDA peptide regulation 2025–2026 timeline.
The melanocortin pathway is theoretically implicated in melanoma development, and case reports of new or changing nevi have been documented in community Melanotan II use. Long-term formal safety studies are absent. Anyone considering Melanotan II use should consult a licensed physician about the underlying melanocortin biology and have any new or changing skin lesions evaluated.
Melanotan II binds multiple melanocortin receptors broadly; PT-141 (Bremelanotide, Vyleesi) was derived from MT-2 as a selective MC4R agonist with FDA approval for hypoactive sexual desire disorder. PT-141 has the focused mechanism and regulatory approval; MT-2 has broader effects without approval.
Independent third-party HPLC certificate of analysis from a lab the vendor does not own or pay, with mass spectrometry identity confirmation. Mass spec distinguishes MT-2 from related compounds including PT-141. COA interpretation in red flags in peptide certificates of analysis.
No. Melanotan II is not approved for human consumption and Peptigrity is an independent review platform, not a medical authority. Community-use dosing varies widely. Anyone considering use should consult a licensed physician.
This section is for educational and informational purposes only and does not constitute medical advice. Melanotan II is not approved by the FDA or any major Western regulator for human use, though it was removed from Category 2 of the FDA 503A bulk substances list in April 2026 and is scheduled for PCAC review in early 2027. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.
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