What it is
PT-141 is bremelanotide, a peptide that acts on the body's melanocortin receptors. It activates several receptor subtypes without selecting strongly between them; at therapeutic doses the two that matter are MC1R and MC4R.
Those two receptors explain most of what the drug does and most of what goes wrong with it. MC4R is involved in central pathways relating to sexual desire. MC1R is involved in pigmentation — which is why one of the documented effects is patches of darkened skin.
It is an approved medicine in the United States, marketed as Vyleesi since 2019, and given by subcutaneous injection with an autoinjector.
What it is approved for
The treatment of premenopausal women with acquired, generalized hypoactive sexual desire disorder.
Each word in that phrase is doing work. Acquired means the condition developed after a period of normal function. Generalized means it is not confined to particular situations or partners. Premenopausal narrows the population further. It is a specific clinical diagnosis, not a general description of low desire, and the approval is drawn to it exactly.
What the approval explicitly excludes
The label states plainly that bremelanotide is not indicated for postmenopausal women or for men, and that it is not intended to enhance sexual performance.
Both exclusions matter, because both describe how the compound is most often discussed online. Use by men sits entirely outside the approval and outside the trials that supported it. And desire and performance are different things — the label distinguishes them, and writing that treats the drug as a performance enhancer is describing a use nobody has studied under that name.
What the research shows
As with any approved drug, the picture is documented rather than inferred: trials in the stated population, a defined endpoint, and a published side-effect profile.
The warnings are specific and follow from the mechanism. Transient increases in blood pressure. Focal hyperpigmentation, noted particularly in patients with darker skin — a direct consequence of activating MC1R. And nausea in roughly 40% of treated patients, which is a high figure and is stated as such. It is contraindicated in uncontrolled hypertension and in known cardiovascular disease.
A compound that reliably raises blood pressure and changes skin pigmentation is not a mild one. Those effects are in the label because they were measured.
Where it stands
Approved as a medicine: yes, in the United States, since 2019, for the indication above.
Sold also as: a research chemical, under the name PT-141, by vendors not selling the approved product. The approved drug and a research-labelled vial of the same nominal compound are not equivalent things: one carries a label, a manufacturer, a batch record and a regulator behind it.
Last checked
2026-09-06. The prescribing information was read on that date.