PT-141 (Bremelanotide)
In Study 1, the US label says the mean desire score rose by 0.5 with Vyleesi and 0.2 with placebo (NCT02333071, US label; checked: 2026-08-25). In Study 2, it rose by 0.6 with the drug and 0.2 with placebo (NCT02338960, same label; checked: 2026-08-25). The two phase 3 trials had 1,247 premenopausal women. Palatin ran and paid for RECONNECT. AMAG paid for help to write the open-label paper (PMID 31599847; checked: 2026-08-25).
What is PT-141?
PT-141 is a name for bremelanotide. The US label calls the drug a synthetic melanocortin receptor agonist (checked: 2026-08-25).
The US GSRS has two linked forms (checked: 2026-08-25). The free base is Bremelanotide, UNII 6Y24O4F92S, CAS 189691-06-3. The salt is Bremelanotide acetate, UNII PV2WI7495P, CAS 1607799-13-2. GSRS links the salt to the free base as its active part and parent. Exact searches for PT-141 and PT 141 found both forms. Vyleesi found the salt. This is a base-and-salt link, not a clash with a second drug.
What is Vyleesi approved for in the US?
The FDA file for NDA 210557 gives an approval date of 21 June 2019. It names AMAG as the firm that filed the drug. Cosette now files the US label.
The US label limits the approval to premenopausal women (checked: 2026-08-25). It covers low sexual desire that began after they once had no such issue. The low desire must occur in all types of sex, with all partners, and in all settings. It must cause marked distress or harm a relationship. It must not stem from a medical or psychiatric condition, a drug, or a problem in the relationship. The label does not cover women past menopause or men. It does not cover use to boost sexual performance.
What did the phase 3 trials find?
The two trials ran for 24 weeks. They were randomised, double-blind and placebo-controlled. The desire score runs from 1.2 to 6. A rise means more desire. The distress score runs from 0 to 4. A fall means less distress.
| Result | Study 1 drug | Study 1 placebo | p | Study 2 drug | Study 2 placebo | p |
|---|---|---|---|---|---|---|
| Mean desire score change | 0.5 (n=313) | 0.2 (n=315) | 0.0002 | 0.6 (n=282) | 0.2 (n=288) | <0.0001 |
| Mean distress score change | -0.7 (n=313) | -0.4 (n=314) | <0.0001 | -0.7 (n=282) | -0.4 (n=285) | 0.0053 |
| Mean change in satisfying sexual events | 0.0 (n=314) | -0.1 (n=316) | 0.76 | 0.0 (n=282) | 0.0 (n=290) | 0.70 |
The label says the desire and distress gaps were significant in both trials. It says the groups did not differ on satisfying sexual events. The tables give no numeric confidence bounds (US label; checked: 2026-08-25).
Palatin ran and paid for the RECONNECT trials. AMAG paid for help to write the open-label paper. Two authors worked for AMAG and owned shares. One author was a Palatin executive and shareholder. He helped design, run and assess the trials (PMID 31599847; checked: 2026-08-25).
What else did the label and trials find?
The US label set out adverse reactions for 627 people who got the drug and 620 who got placebo (checked: 2026-08-25).
| Finding | Drug | Placebo |
|---|---|---|
| Serious adverse reactions | 1.1% | 0.5% |
| Nausea | 40.0% | 1.3% |
| Flushing | 20.3% | 0.3% |
| Reactions at the use site | 13.2% | 8.4% |
| Headache | 11.3% | 1.9% |
| Vomiting | 4.8% | 0.2% |
| Stopped due to an adverse reaction | 18% | 2% |
Nausea caused 8% of the drug group to stop. No one in the placebo group stopped for that cause. The label found focal hyperpigmentation in 1% of the drug group and none on placebo. The spots did not clear in all cases. Tests found peak blood pressure rises of 6 mmHg systolic and 3 mmHg diastolic. Heart rate fell by up to 5 beats per minute. The US label lists uncontrolled high blood pressure and known cardiovascular disease as reasons the drug must not be used.
The 52-week extension had no placebo group. Only about 40% of those who joined it reached the end (PMID 31599847; checked: 2026-08-25). Adverse reactions caused 21.2% of the dropouts. The authors say early loss may skew the data toward those who did well. They say this may make the effect look too large. Palatin paid for the trials. AMAG paid for help to write the paper.
What did the published critique find?
A peer-reviewed paper checked the two RECONNECT trials again (PMID 36809187; abstract checked: 2026-08-25). Its authors found that 8 of 11 trial results named in advance had not been made public. They found effects from nil to small on those results. They called the gains modest. They also said the key scales had little proof of validity for women with HSDD. Only the abstract was open. This page makes no claim beyond that text.
How much human research is on the trial register?
Name and code searches in ClinicalTrials.gov found ten linked trials on 2026-08-25. One is phase 1: NCT03973047. Four are phase 2: NCT00425256, NCT01382719, NCT05709444 and NCT06565611. Three are phase 3: NCT02333071, NCT02338960 and NCT04943068. Two are phase 4: NCT04179734 and NCT06867835.
Four files had results: NCT01382719, NCT02333071, NCT02338960 and NCT04179734. Six had none. Palatin ran six trials. AMAG, Cosette, Kwang Dong Pharmaceutical and Imperial College Healthcare NHS Trust each ran one. No false match was kept.
Evidence tier A marks a named US approval with phase 3 data. It does not show that the drug is approved in Europe.
What is the EU status?
EU status: unclear. The name was not in the EMA central drug report, checked on 2026-08-25. That report does not cover all drug approvals by EU states. The US approval does not settle the status in any EU state.
When was PT-141 first recorded?
The register stores 2019-06. Under its set rule for an approved drug, the approval month counts as a month when the drug was in use. NDA 210557 was approved on 21 June 2019 (checked: 2026-08-25). This is a US drug approval date. It is not a claim that grey-market use began then.
What does grey-market vial research show?
A 2026 preprint looked at 6,285 analytical reports across 14 drugs (DOI 10.20944/preprints202604.1748.v1; checked: 2026-08-25). It says 29.7% of PT-141 samples met both its 95-105% amount range and 99.5% purity cut. The saved text gives no PT-141 sample count. Consumers and synthesis companies submitted samples voluntarily. The sample is not representative of the grey market. The tests did not cover sterility, solvents, particulate matter, stability or structural integrity.
A second paper used LC-HRMS on eight seized samples linked as a group to Melanotan II and the drug (PMID 33245851; checked: 2026-08-25). Its abstract gives no count for the drug alone. It gives no purity or identity-pass rate for the drug. No such rate is guessed here.
What do users report?
No full first-person thread was found in the forum set that could be read under Bremelanotide, PT-141, PT141 or Vyleesi. No quote or claim about a group is used.
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