PT-141

Definition

PT-141 is bremelanotide, a synthetic melanocortin receptor agonist and a metabolite of Melanotan II. It acts centrally rather than on vascular tissue, which distinguishes it mechanistically from the phosphodiesterase inhibitors readers usually compare it to.

It is the least understood entry in this index because its status is the opposite of what its market position suggests. It is widely sold as an unapproved research chemical, and it is an approved drug.

Evidence

The RECONNECT trials improved desire and distress scores without a significant increase in the prespecified count of satisfying sexual events. Their open-label extension retained 272 of 684 entrants through completion, so sustained outcomes among participants cannot be read as randomized long-term proof ^{[3, 13]}. The RECONNECT endpoint review separates these results and their tolerability trade-off.

The development program is the trial record. Across four name variants PubMed returns 121 indexed records, of which 91 carry the Humans subject heading, 16 the clinical-trial publication type, and 14 the randomized-controlled-trial type ^[1]. All sixteen were opened and read, and they trace one continuous program from the 2004 intranasal dose-finding work in men ^[2] through two phase 3 trials in premenopausal women that supported approval ^[3].

One record in that set is retracted, and its own title says so ^[1]. A 2008 double-blind placebo-controlled study of the compound in women with arousal disorder carries a retraction marker in PubMed. It is counted in the sixteen because the publication-type filter counts it; it should not be read as evidence, and a page that reported sixteen trials without opening them would not have known.

The registrational evidence supports the indication it was approved for and nothing wider. The approved population is premenopausal women with acquired, generalized hypoactive sexual desire disorder; the label's own limitations of use state that the product is not indicated for that disorder in postmenopausal women or in men, and is not indicated to enhance sexual performance ^[4]. Every one of those exclusions describes a use the compound is commonly sold for.

Side effects

The Vyleesi label draws its safety data from two 24-week placebo-controlled trials in 1,247 premenopausal women ^[12]. Nausea was the most common adverse reaction, in 40 percent against 1.3 percent on placebo, followed by flushing in 20 percent, injection site reactions in 13 percent and headache in 11 percent; vomiting, cough, fatigue, hot flush, tingling, dizziness and nasal congestion each occurred in 2 to 5 percent ^[12]. Adverse reactions led 18 percent of treated women to stop, against 2 percent on placebo, most often because of nausea ^[12].

Blood pressure rises briefly after each dose. In the trials systolic pressure rose by up to 6 mmHg and diastolic by up to 3 mmHg, peaking 2 to 4 hours after the injection, with a fall in heart rate of up to 5 beats per minute; both usually returned to baseline within 12 hours ^[12]. The drug is contraindicated in uncontrolled high blood pressure and known cardiovascular disease, and not recommended for anyone at high cardiovascular risk ^[12].

Focal darkening of the skin, including the face, gums and breasts, occurred in 1 percent of treated women in the phase 3 trials and in 38 percent of participants in a separate study of consecutive daily use ^[12]. Women with darker skin were more likely to develop it, and it did not resolve in every case after the drug was stopped ^[12]. Nausea needed anti-nausea treatment in 13 percent of treated women ^[12].

Vyleesi may sharply lower blood levels of oral naltrexone, and the label advises against combining it with an oral naltrexone product used for alcohol or opioid addiction ^[12]. Animal studies found fetal harm, so the label advises effective contraception during treatment and stopping the drug if pregnancy is suspected ^[12].

Educational summary of the cited sources, not medical advice; a prescriber weighs these risks against a person’s own history.

Lawful access

The lawful supply route is the approved product. FDA approved bremelanotide injection under new drug application 210557, effective June 21, 2019, as a single-use subcutaneous autoinjector ^[5]. It is dispensed on prescription and remains listed as a marketed prescription product ^[4].

Compounding it is a different question with a clear answer. Bremelanotide appears in no category of the section 503A bulks list published on May 14, 2026 and on no 503B list ^[6]. In April 2020 FDA warned a compounding pharmacy that products it compounded using bremelanotide (PT-141) and twenty-one other substances were not eligible for the exemptions in section 503A(a), because the substances were not the subject of an applicable USP or NF monograph, were not a component of an FDA-approved human drug, and did not appear on the 503A bulks list ^[7]. That letter was issued about nine months after the approval, and this index does not extend its reasoning past the date it was written; what the letter establishes is that FDA has addressed compounded PT-141 directly.

Material sold online as PT-141 for research use is not the approved product and carries none of its assurances. The approved page sets out what an approval does and does not cover.

Related molecules

PT-141 is filed with the melanocortins beside Melanotan II, from which it is derived and from which its regulatory position could hardly differ more: one completed a development program and holds a label, the other left the bulks list with its safety finding intact. The approved peptide drugs table places this product beside the rest of the approved set — including secretin, the one approved peptide here whose bulk substance was also nominated for compounding, and filed as inadequately supported — and the human trial record shows what a completed program looks like as a count.

The evidence review sets the approved indication, its trial record and its label exclusions beside the uses the compound is sold for.

Elsewhere in this index