Source comparison
Quick Comparison
Generic / brand name: PT-141 is known generically as bremelanotide and sold as Vyleesi; Melanotan II (MT-II) has no approved brand name. Molecular formula: PT-141 is C50H68N14O10; Melanotan II is C50H69N15O9. Molecular weight: PT-141 is 1,025.16 g/mol; Melanot
This comparison does not assign a generated winner or score.
- Generic / brand name: PT-141 is known generically as bremelanotide and sold as Vyleesi; Melanotan II (MT-II) has no approved brand name.
- Molecular formula: PT-141 is C50H68N14O10; Melanotan II is C50H69N15O9.
- Molecular weight: PT-141 is 1,025.16 g/mol; Melanotan II is 1,024.18 g/mol.
- Structure: Both are cyclic heptapeptide analogs of alpha-MSH; PT-141 is a lactam analog.
- Key structural difference: PT-141 carries a hydroxyl group in place of an amide, which reduces MC1R activity; Melanotan II has an amide terminus and broad MC1R–MC5R activity.
- Receptor targets: PT-141 primarily targets MC3R and MC4R with reduced MC1R activity; Melanotan II targets MC1R, MC3R, MC4R, and MC5R.
- Primary effects: PT-141 enhances sexual desire and arousal; Melanotan II produces skin tanning, sexual arousal, and appetite suppression.
- FDA status: PT-141 is approved (Vyleesi, NDA 210557, 2019); Melanotan II is not approved for any indication.
- Clinical trial stage: PT-141 has completed Phase III with long-term extension data; Melanotan II has Phase I data only (Dorr 1996, Wessells 1998).
- Half-life: PT-141 approximately 2.7 hours; Melanotan II approximately 1–2 hours.
- Typical dose (sexual function): PT-141 is 1.75 mg subcutaneous; Melanotan II is 0.25–1 mg subcutaneous.
- Tanning effect: PT-141 produces minimal tanning due to reduced MC1R activity; Melanotan II produces significant tanning as its primary mechanism.
- Nausea incidence: PT-141 approximately 40% based on clinical trial data; Melanotan II produces high nausea especially during the loading phase, though no controlled data exists.
- Melanoma risk: Not documented for PT-141; Melanotan II has case reports in peer-reviewed literature and formal warnings from the MHRA and TGA.
- Priapism risk: Low for PT-141 (not prominently reported in trials); documented for Melanotan II — Wessells 1998 showed dose-dependent erections lasting 1–5 hours.
- WADA status: PT-141 is prohibited (S2; possibly captured under broad language); Melanotan II is prohibited (S2; explicitly named).
- Availability: PT-141 is available by prescription (Vyleesi), through compounding, or as a research chemical; Melanotan II is a research chemical only, not available via prescription.