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Longevity & Skin
A powerful but unapproved tanning peptide — with real safety warnings from regulators.
Sexual Health
Works through the brain, not blood flow — and it's FDA-approved for women.
Melanotan II is not FDA-approved and rated 3/5 for evidence; PT-141 is approved in another form or use and rated 4/5. PT-141 has more human evidence behind it. Melanotan II is banned in sport by WADA; PT-141 is not. Melanotan II is listed under Longevity & Skin; PT-141 under Sexual Health.
| Compare | Melanotan II A powerful but unapproved tanning peptide — with real safety warnings from regulators. | PT-141 Works through the brain, not blood flow — and it's FDA-approved for women. |
|---|---|---|
| Category | Longevity & Skin | Sexual Health |
| Evidence | 3/5Small, older human pilot studies (tanning; erectile function) plus a long list of case reports of harms. No modern trials and no approval. | 4/5Phase 3 RCTs in women (RECONNECT) led to FDA approval; men's data is smaller. |
| FDA status | Not FDA-approved; FDA has acted against sellers | Approved (narrow indication): Vyleesi (2019), HSDD in premenopausal women only |
| WADA (sport) | Banned | Not on the Prohibited List |
| Also known as | MT-II, MT2, 'Barbie drug' | Bremelanotide, Vyleesi |
| How it works | A non-selective melanocortin receptor agonist. MC1R activation drives tanning; MC3R/MC4R activation in the brain affects appetite and sexual function. That lack of selectivity is why side effects are common. | Melanocortin-4 receptor agonist in the hypothalamus; acts on desire pathways rather than vascular function. |
| Half-life | Roughly 1 hour or less (short); tan builds over repeated doses | About 2–3 hours |
| Commonly reported doses |
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| Route | Subcutaneous | Subcutaneous (abdomen/thigh) |
| Good once mixed | ~28 days in the fridge | ~28 days in the fridge |
| Top side effects |
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| Lowest research-listing price per mg | $1.80 (10 mg vial, 40% off) | $1.80 (10 mg vial, 40% off) |
| Latest lab purity | 99.83% (lot MII0002) | 99.91% (lot PT0002) |
Want a third? Add another peptide. Doses are commonly reported ranges, not recommendations.
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Melanotan II is not FDA-approved and rated 3/5 for evidence; PT-141 is approved in another form or use and rated 4/5. PT-141 has more human evidence behind it. Melanotan II is banned in sport by WADA; PT-141 is not. Melanotan II is listed under Longevity & Skin; PT-141 under Sexual Health.
Melanotan II: Not FDA-approved; FDA has acted against sellers. PT-141: Approved (narrow indication): Vyleesi (2019), HSDD in premenopausal women only. Regulations change, so confirm with the FDA.
Melanotan II is rated 3 out of 5: Small, older human pilot studies (tanning; erectile function) plus a long list of case reports of harms. No modern trials and no approval. PT-141 is rated 4 out of 5: Phase 3 RCTs in women (RECONNECT) led to FDA approval; men's data is smaller. The scale is explained on our methodology page.
Melanotan II is banned by WADA, by name or as part of a named class. PT-141 is not named on the WADA list, though the general rule on non-approved substances (S0) can still apply.