Bremelanotide
Bremelanotide is a peptide medicine that acts on melanocortin receptors in the brain. In the US it is approved for premenopausal women with acquired, generalised hypoactive sexual desire disorder (HSDD).
Reference information, not medical advice. Enhanced Training Studio doesn't sell, supply or recommend any substance. Doses are left out on purpose: only a prescriber can set one. How this library is written.
What it is
Bremelanotide is a synthetic peptide sold in the US as Vyleesi. It is given as an injection under the skin. The US Food and Drug Administration (FDA) approved it on 21 June 2019 [3]. It is not a hormone and does not act on the growth hormone system; it is listed in this section of the library alongside other injectable peptides.
Products sold online as "PT-141" are not the licensed medicine. They are not made or checked to medicine standards, so their content, purity and sterility are unknown.
How it works
Bremelanotide activates melanocortin receptors, particularly the melanocortin 4 (MC4) receptor in the central nervous system. Exactly how this improves sexual desire is not known [1, 2]. After injection, levels peak in about 1 hour and the half-life is about 2.7 hours [2].
Approved medical uses
In the US, bremelanotide is approved for premenopausal women with acquired, generalised hypoactive sexual desire disorder (HSDD): low sexual desire that causes marked distress or relationship difficulty and is not due to another medical or psychiatric condition, relationship problems or medicines [1, 3]. It is not approved for postmenopausal women or for men, and it is not intended to enhance sexual performance [2]. It should only be used under medical supervision.
What the research shows
- Main trials: approval was based on two 24-week randomised, placebo-controlled trials in 1,247 premenopausal women with HSDD [2].
- Desire and distress: in both trials, women taking bremelanotide had a small improvement in a sexual desire score and a small reduction in distress about low desire, compared with little or no change on placebo [1].
- Sexual events: there was no significant difference from placebo in the number of satisfying sexual events, a secondary outcome [1].
- Tolerability: 18% of women taking bremelanotide stopped treatment because of side effects, compared with 2% on placebo. Nausea was the most common reason (8%) [1].
- Long-term safety: after approval, the FDA required a pregnancy registry and other studies of pregnancy and breastfeeding outcomes [3].
Known risks and side effects
- Nausea in about 40% of women in the main trials, with 13% needing anti-sickness medicine [1]. Vomiting in about 5% [2].
- Flushing (about 20%), injection-site reactions (about 13%) and headache (about 11%) [2].
- A short-lived rise in blood pressure and fall in heart rate after each dose. In studies, systolic blood pressure rose by up to 6 mmHg and diastolic by up to 3 mmHg, peaking 2 to 4 hours after the dose and returning to normal within 12 hours [1, 2].
- It must not be used by people with uncontrolled high blood pressure or known cardiovascular disease [2].
- Focal hyperpigmentation (darkening of patches of skin) in about 1% of trial participants, more often in people with darker skin. It did not clear in all cases [2].
- It markedly lowers blood levels of oral naltrexone, so it should be avoided with naltrexone products used to treat alcohol or opioid dependence [2].
- The label advises women who could become pregnant to use effective contraception and to stop treatment if pregnancy is suspected [1].
Blood tests commonly monitored
The US label does not list routine blood tests for bremelanotide. The checks it focuses on are:
- Blood pressure, because it is contraindicated in uncontrolled hypertension and causes a temporary rise after each dose [1, 2].
- Skin changes (hyperpigmentation) [2].
- Pregnancy status in women who could become pregnant [1].
If you and your doctor are monitoring treatment, Enhanced Training Studio keeps a private log on your phone: what you take and when, your blood test results over time, and how you feel. How tracking works.
Sources
- US Food and Drug Administration. Vyleesi (bremelanotide injection): prescribing information. Revised January 2025. FDA Label
- US Food and Drug Administration. Vyleesi (bremelanotide injection): prescribing information. 2020. FDA label (PDF)
- US Food and Drug Administration. NDA 210557 approval letter for Vyleesi. 21 June 2019. FDA (PDF)
Related
Last reviewed 7 October 2026. General information, not medical advice. Found a mistake? Email [email protected].