PT-141 vs Melanotan I
It is sold online as a sex-drive booster, mostly to men. The approved form, bremelanotide, was tested in 1,267 women with small gains; for men there are only two small studies from 2004. Sold as a safe way to tan without sun. It darkened skin in a 65-person trial. The approved version is a different product for a rare sun-pain disease.
Both sit at grade B: some human evidence. Neither is FDA approved.
Evidence
BSome human evidence
BSome human evidence
Human studies cited
Animal or cell studies cited
Why the grade
For the approved use there are two randomized, placebo-controlled phase 3 trials (RECONNECT, 1,267 women combined), which is A-level evidence, though a re-analysis argues the effect on desire is small. For the use PT-141 is actually sold for online, libido and erections in men, the evidence is two small 2004 studies, one of a nasal spray that was later abandoned and one of an injection, so the compound as marketed sits at B.
For the tanning use it is sold for, the evidence is one placebo-controlled trial in 65 fair-skinned volunteers that measured melanin density and UV damage markers, a surrogate for sunburn protection. The approved use in erythropoietic protoporphyria rests on two randomized placebo-controlled trials totaling 168 patients. The tanning use has one trial with surrogate endpoints, which is B; no trial has tested cosmetic tanning in the general population or compared it with sunscreen.
FDA
Not approved
PT-141 is the development code for bremelanotide, which the FDA approved in June 2019 as Vyleesi for premenopausal women with acquired, generalized hypoactive sexual desire disorder. Products sold online as PT-141 are not Vyleesi, are not approved by the FDA for any use, and are sold as research chemicals, most often to men, a population the drug was never approved for.
Not approved
Melanotan I is the same molecule as afamelanotide, which the FDA approved in 2019 as the Scenesse implant for adults with erythropoietic protoporphyria. Injectable 'Melanotan I' sold online for tanning is not approved by the FDA for any use and is sold as a research chemical.
Sold for
PT-141 is sold on the gray market as a libido and erection booster for men and women that works through the brain instead of blood flow.
Melanotan I is sold as the 'safer' tanning peptide, the one that became a real drug, promising a tan without sun and protection against burning.
Studies say
Two phase 3 trials support a modest effect on sexual desire in premenopausal women with HSDD, which is what the FDA approved; the evidence in men is two small 2004 studies, one nasal and one injected, from a program that was abandoned, and nausea affects about 40 percent of users.
A 65-person placebo-controlled trial showed more melanin and less UV damage in fair skin, and two trials in 168 porphyria patients led to approval of the implant, so the evidence is grade B for tanning and the approved product is a different formulation for a rare disease.
Class
MC4R agonist
MC1R agonist
Route
Injection
Injection