Bremelanotide: evidence, FDA status and research

It is an injection for women who have low sexual desire. Two trials in 1,267 women found small gains on questionnaires, and about 40% of users felt sick.

Sold for

Bremelanotide is marketed as an on-demand injection for low sexual desire in women and is sold online, often as PT-141, as a libido booster for anyone.

Studies say

Two randomized trials in 1,267 women showed statistically significant but small improvements in questionnaire scores for desire and distress, no increase in satisfying sexual events, and nausea in about 40% of users (grade B).

Why grade B. Approval rests on the two RECONNECT phase 3 trials, which randomized 1,267 premenopausal women and met their co-primary endpoints on desire and distress questionnaires. The effect sizes were small, the number of satisfying sexual events did not increase, dropout for nausea was high, and an independent reanalysis questioned the validity of the outcome questionnaires. Approved on RCTs but with surrogate questionnaire endpoints and contested benefit is grade B. ⁴⁵

FDA. Bremelanotide is FDA-approved and sold as Vyleesi, a self-administered subcutaneous autoinjector, approved in June 2019 for premenopausal women with acquired, generalised hypoactive sexual desire disorder (HSDD). It is not approved for men or for postmenopausal women. ²³

Written from 5 cited sources. Fact-checked 2026-10-27: 18 claims checked, 4 corrected, 1 sources unreachable. Last refreshed 2026-10-27. Not physician reviewed.

What this means for you

What people take it for: Low sexual desire
Can a US doctor prescribe it?: Yes, FDA approved for low sexual desire in women before menopause.
Properly tested in people?: Yes, in two controlled trials of 1,267 women, though the gains were small.

Evidence checklist

Randomised controlled trial RECONNECT trials, placebo-controlledyes
Human study over 100 people RECONNECT, 1,267 premenopausal womenyes
More than one research group Both trials by same program; one reanalysisno
Clinical outcomes, not surrogate markers Questionnaire scores; satisfying events unchangedno
Human safety data beyond case reports Nausea, blood pressure data in trialsyes

Drawn from the cited studies below. A dash means the sources give no information.

What it is

Bremelanotide is also known by its development code PT-141. It is a lab-made cyclic peptide with seven amino acids. It comes from melanotan II, which is itself a lab-made version of alpha-melanocyte-stimulating hormone. Researchers found it by accident. Melanotan II was being tested as a tanning agent, and it caused unexpected erections in male volunteers. ¹

Palatin Technologies developed it. First came a nasal spray for erectile dysfunction, which was dropped after blood pressure rises. Then came an injection under the skin for women. AMAG Pharmaceuticals launched Vyleesi in 2019. The rights later went back to Palatin and then to Cosette Pharmaceuticals. Users inject it in the thigh or belly about 45 minutes before expected sex. ²³

How it works

Bremelanotide activates melanocortin receptors. Its main effect is thought to come through the melanocortin-4 receptor (MC4R) in the hypothalamus and other brain regions tied to arousal. Sildenafil-type drugs act on blood vessels. This drug acts on the brain's desire pathways, probably by changing dopamine release. It also activates MC1R on pigment cells, which is why it can darken skin. The exact brain circuits in humans are not known. ¹³

What human research shows

The RECONNECT programme ran two identical randomized, double-blind, placebo-controlled trials. Each lasted 24 weeks. Together they enrolled 1,267 premenopausal women with HSDD. They were published in Obstetrics & Gynecology in 2019. Both trials met their two main goals. On the desire domain of the Female Sexual Function Index, women on the drug scored about 0.3 to 0.4 points better than placebo, on a 1.2 to 6 scale. On the distress item of the Female Sexual Distress Scale, they scored about 0.3 points better, on a 0 to 4 scale. ⁴

A key secondary goal was the number of satisfying sexual events per month. It did not differ from placebo. Roughly 18% of women on bremelanotide dropped out because of side effects, against about 2% on placebo. In 2023, an independent reanalysis in the Journal of Sex Research looked at the data again. It found little proof that the questionnaires are valid in women with HSDD. It also found that 8 of the 11 outcomes registered on ClinicalTrials.gov had gone unpublished. Effect sizes on those outcomes ranged from nil to small. ⁴⁵

Study	Model	Finding
RECONNECT trials, Obstet Gynecol 2019	Humans, n=1,267 premenopausal women with HSDD, two randomized double-blind placebo-controlled trials, 24 weeks	Small but statistically significant improvements in desire and distress scores; no increase in satisfying sexual events; 18% discontinued for adverse events versus 2% on placebo. ⁴
Independent reanalysis, J Sex Research 2023	Reanalysis of RECONNECT trial data	The efficacy questionnaires had little validity evidence in HSDD, 8 of 11 registered outcomes were previously unpublished, and effects on them ranged from nil to small. ⁵
FDA label, Vyleesi 2019	Regulatory review of phase 3 safety	Nausea in 40%, transient blood pressure increase, focal hyperpigmentation in about 1%, and restrictions on dosing frequency. ³

Safety

About 40% of women in the trials had nausea, most often after the first injection. Of all women, 13% needed anti-nausea medication. Other common effects were flushing, injection-site reactions, headache and vomiting. ³⁴

Bremelanotide briefly raises blood pressure (around 6 mmHg systolic) and slows the heart rate. Both peak within hours of a dose. The label does not recommend it for women with uncontrolled high blood pressure or known heart disease. It limits use to one dose in 24 hours and eight per month. About 1% of users developed dark patches on the face, gums or breasts. These did not always fade after stopping. The drug also slows stomach emptying. It can reduce how well pills taken at the same time are absorbed. ³

Questions for your clinician

How large was the benefit in the trials compared with placebo, and would I notice it?
Do my blood pressure or heart history make this a poor fit?
What happens if I develop darkening of the skin or gums?

Questions people ask

Is bremelanotide FDA-approved?

Yes, as Vyleesi, since June 2019. It is for premenopausal women with acquired, generalised hypoactive sexual desire disorder. It is not approved for men or for postmenopausal women. The PT-141 sold by online vendors is an unregulated version of the same peptide. ²³

How well does it work?

Modestly. In 1,267 women, it improved desire and distress scores by a few tenths of a point more than placebo. It did not raise the number of satisfying sexual encounters. An independent reanalysis found the gains modest. It also questioned whether the questionnaires measure what they claim. ⁴⁵

Does it work for men?

Researchers tested a nasal spray in men with erectile dysfunction in the 2000s. It showed some effect. Work stopped because blood pressure rose. No form is approved for men. ¹³

Which adverse reactions are most common?

About 40% of users get nausea. Others get flushing, headache and injection-site reactions. Blood pressure rises for a few hours after each dose. About 1% of users develop dark skin patches that may not fade. ³⁴

How is bremelanotide related to melanotan II?

It is a metabolite and close lab-made cousin of melanotan II, an unapproved tanning peptide. Its sexual effect was found during melanotan II trials. Melanotan II is still illegal to sell for human use. Bremelanotide went through formal trials and won approval for one use. ¹

Citations

ScienceDirect topics: bremelanotide sciencedirect.com
Palatin Technologies 2019: FDA approves Vyleesi (bremelanotide injection) palatin.com
FDA: Vyleesi (bremelanotide) prescribing information, 2019 accessdata.fda.gov
Kingsberg 2019, Obstetrics & Gynecology: bremelanotide for HSDD, RECONNECT randomized trials doi.org
Journal of Sex Research 2023: independent reanalysis of the bremelanotide trials doi.org