- What it is: A synthetic cyclic peptide that acts at the MC3 and MC4 melanocortin receptors.
- Research areas: sexual desire and arousal (the main human trial literature) and melanocortin-pathway biology.
- Evidence level: Real human evidence, but for one narrow use only. Two large phase 3 trials in premenopausal women, plus an FDA approval of a finished prescription drug for that single diagnosis. Outside that, the record is thin.
- The short version: In two large trials researchers watched it raise measured sexual-desire scores and lower related distress in premenopausal women, and regulators later approved a finished drug version for that one use. This page reports what researchers studied. It is not a recommendation to use the compound, and this material is supplied for research only.
What it is
PT-141 is the development code for bremelanotide, which is the generic name. It is a synthetic peptide of seven amino acids, six of them closed into a ring. It is an analog of alpha-MSH (alpha-melanocyte-stimulating hormone), a hormone the body makes.
Specs at a glance. Reference values for the compound named on the label, from PubChem or KEGG. They describe the compound, not a measurement of the vial you receive. Molecular weight is the free base (the peptide alone, without a salt). Synthetic peptides are usually supplied as a salt such as acetate or TFA, and the salt in this vial has not been confirmed.
| Compound | PT-141 (bremelanotide) |
|---|---|
| Sequence | Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH (7 aa, lactam Asp-Lys) |
| Molecular formula | C50H68N14O10 |
| Molecular weight | 1025.18 g/mol (average, free base) |
| CAS number | 189691-06-3 |
| Reference record | PubChem CID 9941379 |
| Form | Lyophilized (freeze-dried) powder in one sealed vial |
| Vial size | 10 mg per vial |
| Storage (dry powder) | -20°C or colder, long term. Keep the vial sealed and away from light. |
| Lab report | Janoshik Analytical, August 2026. Ordered by the supplier, not by Etched Research. The report carries no lot number, so it is not matched to the vial you receive. Results on this page ↓ · All lab reports → |
What the evidence is
PT-141 has human trial data, including two phase 3 trials with 1,267 participants. The large trials all ran in premenopausal women diagnosed with hypoactive sexual desire disorder (HSDD) or a related sexual dysfunction diagnosis. Earlier, smaller studies gave it as a nasal spray.
| Study | Type | Who | What was given | What it measured | What it found |
|---|---|---|---|---|---|
| Kingsberg et al., Obstetrics and Gynecology, 2019 | Human, two identical phase 3 trials, randomized, double-blind, placebo-controlled | 1,267 premenopausal women with HSDD | 1.75 mg as needed, 24 weeks | A desire score and a score for distress about low desire | Across both trials the desire score rose 0.35 points more than placebo and the distress score fell 0.33 points more. Nausea, flushing and headache were each reported in 10% or more |
| Simon et al., Obstetrics and Gynecology, 2019 | Human, open-label extension, no placebo | 684 women from the phase 3 trials (272 finished) | Open-label, as needed, 52 weeks | The same two scores, plus side effects | Score changes were sustained over the extension. Drug-related nausea 40.4%, flushing 20.6%, headache 12.0%. No new safety signals reported. Fewer than half of those who enrolled finished |
| Clayton et al., Women’s Health, 2016 | Human, phase 2b, randomized, placebo-controlled, dose-finding | Premenopausal women with female sexual dysfunction (327 in the efficacy analysis) | 0.75, 1.25 or 1.75 mg as desired, 12 weeks | Satisfying sexual events per month, plus function and distress scores | At the two higher doses combined, events rose 0.7 a month against 0.2 on placebo, and both scores improved more than placebo. Side effects were nausea, flushing and headache |
| White et al., Journal of Hypertension, 2017 | Human, randomized, double-blind, placebo-controlled | 397 premenopausal women with female sexual dysfunction and normal or controlled blood pressure | 0.75, 1.25 or 1.75 mg | 24-hour blood pressure and heart rate | Systolic blood pressure rose 2.4 to 3.2 mmHg more than placebo in the 4 hours after dosing at the two higher doses, with peaks usually under 15 minutes. Heart rate fell 4.6 to 4.7 beats a minute at 1.75 mg |
| Diamond et al., Journal of Sexual Medicine, 2006 | Human, randomized, double-blind, placebo-controlled crossover | 18 premenopausal women with sexual arousal disorder | One 20 mg dose, and placebo at a separate session | A genital blood-flow measure in the clinic, and self-reported response over 24 hours | More women reported moderate or high desire after bremelanotide than after placebo. The blood-flow measure did not change significantly |
| Spielmans, Journal of Sex Research, 2021 | Independent re-analysis of the two phase 3 trials, from FDA application data | The same phase 3 population | Not applicable (re-analysis) | Efficacy, dropout for side effects, and who went on to the extension | Found efficacy results similar to the original report. Dropout for side effects was much higher on bremelanotide, and fewer bremelanotide participants both finished the trial and chose to enter the open-label extension |
Last reviewed 2026-09-24. Staff of Palatin Technologies, the company that developed bremelanotide, are authors on every study above except the 2021 re-analysis. How it works, and what none of this establishes, is on the full research summary →
Lab reference
Janoshik Analytical tested PT-141 10mg from supplier stock on 18 August 2026. One vial measured 99.847% purity and 10.68 mg of PT-141 against the 10 mg label. See it on the lab reference page →
What that report does not cover: it is a reference test of the compound from supplier stock, not a test of the vial in your order. It names no batch, so it cannot be matched to a lot. It did not test for endotoxin, sterility or heavy metals.
Storage and shipping
Ships as lyophilized powder in a sealed vial. Store the powder frozen at -20°C. US addresses only. Shipping costs and cutoff times →
Questions about PT-141
Is PT-141 the same thing as bremelanotide?
Yes. PT-141 is the development code and bremelanotide is the generic drug name (INN and USAN) for the same molecule. Papers also write it as PT 141 or PT141.
Is there human data?
Yes. The two phase 3 trials enrolled 1,267 premenopausal women with HSDD, and every trial listed above ran in women with a sexual dysfunction diagnosis. Those trials also recorded nausea, flushing, headache and small, short rises in blood pressure. None of this is a safety conclusion.
Does Etched Research sell Vyleesi?
No. Vyleesi is a prescription drug whose active ingredient is bremelanotide, as an acetate salt. The FDA first approved it in 2019. Etched Research sells PT-141 (bremelanotide) as a research compound for laboratory use only. It is not for human use.
Is there a lab report for PT-141?
Yes. Janoshik Analytical tested PT-141 10mg from supplier stock on 18 August 2026: 10.68 mg of PT-141 against the 10 mg label, and 99.847% purity. The Lab reference section above says what that report does and does not cover.
Shipping, eligibility and what comes in the box: store FAQ →
For research use only. Not for human consumption.
