Last updated 18 September 2026 · SARMs Store editorial team. Products on this site are supplied strictly for laboratory research and are not for human consumption. This guide summarises published research; it is not medical advice and contains no instructions for use. 18+ only.
PT-141 at a glance
| Class | Cyclic heptapeptide melanocortin receptor agonist, a metabolite of Melanotan II |
|---|---|
| Developed by | Palatin Technologies, 2000s to 2019 |
| Highest evidence | Two phase III trials (RECONNECT); US FDA approval 2019 as Vyleesi, an injectable, for one indication in premenopausal women |
| Studied for | Melanocortin-4 receptor signalling in the central nervous system |
| Format | Capsules (research format; oral bioavailability of the peptide is very low) |
| Storage | Cool, dry, away from light |
| UK status 2026 | Research chemical; no UK or EU licence (EU application withdrawn 2020); not named on the WADA list |
What PT-141 is
PT-141, generic name bremelanotide, is a cyclic seven-amino-acid peptide that activates melanocortin receptors, mainly the MC4 receptor in the brain. It was identified as a metabolite of Melanotan II, the tanning peptide, during studies in the 1990s, and Palatin Technologies developed it as a medicine. Unlike Melanotan II it has little effect on pigmentation because it is less active at the MC1 receptor. It is a genuinely licensed medicine in one country for one indication, which sets it apart from most research peptides.
What the research found
Licensed use. In June 2019 the US FDA approved bremelanotide as Vyleesi, a subcutaneous autoinjector, for hypoactive sexual desire disorder in premenopausal women, on the basis of two phase III trials (RECONNECT) in about 1,200 women. The effect over placebo was modest on the trial scales, and nausea was the most common side effect. Palatin submitted to the European Medicines Agency and withdrew the application in 2020, so there is no EU or UK licence.
Earlier programme. An intranasal form was studied in men and women in the 2000s and dropped because of blood pressure increases. The licensed product carries a warning on transient blood pressure rises.
Oral form. The material sold for research as capsules is a different research question. Peptides of this size are largely broken down in the gut and the published oral bioavailability of bremelanotide is very low, which is why the licensed product is injected. No study supports an oral form.
What is missing. Any UK or EU licence, any study of oral capsules, and any trial outside the licensed indication.
Stability, storage and handling
Capsules should be kept cool, dry and away from light in the sealed container. The certificate should show HPLC purity and mass spectrometry identity of the peptide and the quantity per capsule.
Legal status in the UK, 2026
Not a controlled substance under the Misuse of Drugs Act 1971. Bremelanotide has no UK marketing authorisation and the EU application was withdrawn, so in the UK it is not a licensed medicine. The MHRA has taken enforcement action against UK sellers of melanocortin peptides marketed for human use, so research-grade PT-141 cannot be sold or advertised for human use and is supplied strictly for laboratory research. Not named on the WADA Prohibited List.
What to check before buying
Quantity per capsule, HPLC purity, mass spectrometry identity, a batch number matching the certificate. Every Origin Peptides batch is independently tested and its certificate of analysis is published on the product page and the Lab Testing page.
Frequently asked questions
Is PT-141 the same as bremelanotide and Vyleesi?
Yes. PT-141 is the research code, bremelanotide the generic name, Vyleesi the US brand of the injectable.
Is PT-141 licensed in the UK?
No. The US licence is for one injectable product and one indication; the EU application was withdrawn in 2020.
Does PT-141 cause tanning?
Far less than Melanotan II, because it is weak at the MC1 receptor.
Do oral PT-141 capsules work like the injectable?
No study says so; published oral bioavailability is very low.
Is PT-141 legal in the UK?
Legal to buy and possess as a research compound; not lawful to sell or advertise for human consumption.
Key references
Kingsberg SA, Clayton AH, Portman D, et al. Bremelanotide for the treatment of hypoactive sexual desire disorder: two randomized phase 3 trials. Obstetrics and Gynecology. 2019;134(5):899-908. Molinoff PB, Shadiack AM, Earle D, Diamond LE, Quon CY. PT-141: a melanocortin agonist for the treatment of sexual dysfunction. Annals of the New York Academy of Sciences. 2003;994:96-102. European Medicines Agency. Withdrawal of the marketing authorisation application for Vyleesi (bremelanotide), 2020.
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Research products: Origin Peptides PT-141 capsules · Full Origin Peptides range · Lab Testing