PT-141 vs Melanotan II
Written by Aaron CuhaReviewed Sep 2026
The short answer
An approved drug that works on the melanocortin switches, against an unapproved one.
- PT-141 people
- 2,355
- PT-141 nulls
- 0
- Melanotan II people
- 1,310
- Melanotan II nulls
- 0
Dose
Approved medicine. No human dose established for unlabelled uses
Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose.
FDA-approved (Vyleesi)
Dose
No human dose established
Amounts that circulate in forums and on vendor pages are not a human dose. Amounts that were given in studies sit in Human evidence on this page.
Commonly reported amounts, in mcg. Melanotan II has no approved label anywhere.
Amounts commonly reported by people buying Melanotan II, recorded for this archive's reconstitution calculator, are 100, 250 and 500 mcg. They are self-reports rather than trial doses, and this archive does not recommend any of them. No human dose has been established for Melanotan II.
| Reported amount | Where the number comes from |
|---|---|
| 100 mcg | Commonly reported, no published human dosing trial |
| 250 mcg | Commonly reported, no published human dosing trial |
| 500 mcg | Commonly reported, no published human dosing trial |
First-hand reports are counted on each profile and never added together. This page sets two published records side by side. It does not pick a winner.
Column A
PT-141Bremelanotide (melanocortin receptor agonist)
An FDA-approved shot for low sexual desire in women who have not gone through menopause.
Column B
Melanotan IIMelanotan II (melanocortin receptor agonist)
An unapproved tanning and sex drive shot. It has real safety concerns.
Side by side, on the facts we can check
| What we compare | PT-141 | Melanotan II |
|---|---|---|
| Category | Melanocortin | Melanocortin |
| FDA status | FDA-approved (Vyleesi) | Not approved; regulators have warned about it |
| Half-life | ~2.7 hours | ~1 hour |
| Molecular weight | 1,025.2 Da | 1,024.2 Da |
| How it works | It switches on melanocortin receptors in the brain, mostly one called MC4R. Those are part of the brain's desire and arousal pathways. | It switches on many melanocortin receptors at once. MC1R makes the skin darken. MC4R, in the brain, affects appetite and sex drive. |
| Studies in people | 4 | 8 |
| Evidence | Strong: 4 completed trials, 2,355 people given it | Strong: 5 completed trials, 1,310 people given it |
| Legal status, US | FDA-approved, prescription only | Not approved; research use only |
Frequently asked questions
What is the difference between PT-141 and Melanotan II?
PT-141: An FDA-approved shot for low sexual desire in women who have not gone through menopause. Melanotan II: An unapproved tanning and sex drive shot. It has real safety concerns.
Which has stronger research evidence, PT-141 or Melanotan II?
Each compound gets a band worked out from facts we counted, with the math shown. PT-141 is Strong (4 completed trials, 2,355 people given it). Melanotan II is Strong (5 completed trials, 1,310 people given it). That counts how much has been done in people. It does not rate whether either one works, and neither one is called the winner.
Are PT-141 and Melanotan II FDA-approved?
PT-141: FDA-approved (Vyleesi). Melanotan II: Not approved; regulators have warned about it.
Related posts
Blog articles that cover PT-141 or Melanotan II, newest first.
Reviewed Sep 2026. This page puts two published records side by side. It is for learning, and it is not medical advice. When this site shows a dose, it is the dose a trial or a clinic actually used, or what people say they did, with the source attached. None of it tells you what to take.