Compound Profile
PT-141: The Melanocortin Agonist That Became Vyleesi
Published: August 24, 2026
TL;DR
PT-141 and bremelanotide are names for the same compound. Vyleesi is the specific drug product FDA approved on June 21, 2019 for premenopausal women with acquired, generalised hypoactive sexual desire disorder. Its label is narrow: it excludes postmenopausal women, men, and enhancement of sexual performance. The compound is also closely related to Melanotan II, but it is not another name for Melanotan II. Peer-reviewed literature describes PT-141 as the carboxylate derivative of that earlier molecule.
PT-141 does not have a Curo product page. Curo's general research catalogue, lot-specific COA lookup, and Research Use Only policy are the general reference points for compounds Curo does list. This article is a neutral compound profile built around substance identity, the FDA record, and the research status current to August 24, 2026.
A melanocortin receptor agonist
PT-141, bremelanotide, and Vyleesi are often used in the same conversation, but the names are not interchangeable at every level. PT-141 and bremelanotide identify the compound. Vyleesi names an FDA-approved product containing bremelanotide.
The substance record makes the identity unusually clear. FDA's substance registry lists bremelanotide free base under UNII 6Y24O4F92S, gives CAS number 189691-06-3, and includes "PT-141 FREE BASE" as a synonym. This supports a direct identity relationship between PT-141 free base and bremelanotide free base, rather than an analogy based on similar compounds.
Bremelanotide belongs to the melanocortin signalling system. The NCBI clinical review describes it as a melanocortin receptor agonist acting at MC1R and MC4R, with MC4R understood to mediate the effects relevant to the approved sexual-desire indication. Receptor agonism is the central pharmacological classification. It also helps explain why comparisons with compounds outside the melanocortin family can obscure more than they clarify.
The Melanotan II connection
The relationship with Melanotan II is chemical, historical, and easy to compress into the wrong conclusion. Peer-reviewed literature describes PT-141 as the carboxylate derivative of MT-II, or Melanotan II. In practical naming terms, PT-141 descends from Melanotan II but is a distinct molecule.
That distinction resolves two common search questions at once. PT-141 is bremelanotide. PT-141 is not Melanotan II. Calling one a derivative of the other identifies parentage without making the names synonymous. It also keeps the evidence attached to each molecule separate, which matters when reading receptor studies, trial registries, and regulatory documents.
Chemical identity is only one documentation layer. For compounds that appear in Curo's catalogue, the guide to matching a certificate of analysis to its physical lot explains how identity and batch records connect. A shared family history or research nickname cannot replace a lot-specific analytical record.
From development programme to approved product
The pivotal programme consisted of two Phase 3 RECONNECT studies. NCT02333071, sponsored by Palatin Technologies, enrolled 723 participants and ran from December 2014 to June 30, 2017. NCT02338960, also sponsored by Palatin Technologies, enrolled 714 participants and ran from January 2015 to June 29, 2017. Both studies concerned acquired, generalised hypoactive sexual desire disorder in premenopausal women.
The trials were reported together by Kingsberg and colleagues in "Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials," published in Obstetrics and Gynecology in 2019, volume 134, issue 5, pages 899 to 908. Their publication established a peer-reviewed account of the pivotal programme without changing the scope later set by the approved label.
FDA approved Vyleesi on June 21, 2019 under NDA 210557. The approval letter is addressed to AMAG Pharmaceuticals, Inc., and identifies the indication as acquired, generalised hypoactive sexual desire disorder in premenopausal women. The general product-specific nature of drug approvals is covered in more depth in Curo's profile of tesamorelin and its approved product.
What the label actually covers
The most informative part of the Vyleesi label is its boundary language. The label says Vyleesi is not indicated for hypoactive sexual desire disorder in postmenopausal women or in men, and is not indicated to enhance sexual performance. It also lists uncontrolled hypertension and known cardiovascular disease as contraindications.
Those limitations are unusually explicit. The indication names a defined population and condition, while the exclusions close off three broader readings that the compound's general visibility might otherwise invite. The approved record does not turn PT-141 into a category-wide term for every melanocortin compound or every research setting.
Regulatory scope and analytical documentation remain distinct parts of a research record. For compounds Curo lists, its quality and testing standard consists of exactly three methods: HPLC, LC-MS, and endotoxin testing. Those methods document characteristics of a specific lot. They do not reproduce the manufacturing, review, or application file of Vyleesi.
Where PT-141 research goes next
Bremelanotide remains in clinical development outside the approved indication. NCT06565611 is a Phase 2 study of bremelanotide combined with tirzepatide in obesity, sponsored by Palatin Technologies. It started on August 5, 2024 and is listed as active and not recruiting. The registry can be followed for later changes in study status, posted results, and publication references.
Compounding policy followed a different 2026 track. PT-141 was not among the substances reviewed at the July 23 and 24, 2026 Pharmacy Compounding Advisory Committee meeting. The meeting notice covered BPC-157, KPV, TB-500, MOTS-c, emideltide, semax, and epitalon.
For PT-141, the next useful evidence will come from clearly identified studies and updated primary records. Substance synonyms, parentage, an approved label, and an active Phase 2 programme already form a substantial record. Keeping those elements separate preserves the specificity that makes the compound notable.
Common questions
Are PT-141 and bremelanotide the same compound?
Yes. FDA's substance registry places "PT-141 FREE BASE" in the synonym list for bremelanotide free base under UNII 6Y24O4F92S.
Is PT-141 the same as Melanotan II?
No. The literature describes PT-141 as the carboxylate derivative of Melanotan II. They are chemically related but distinct molecules.
What did FDA approve?
FDA approved Vyleesi under NDA 210557 on June 21, 2019 for premenopausal women with acquired, generalised hypoactive sexual desire disorder.
What does the Vyleesi label exclude?
The label excludes hypoactive sexual desire disorder in postmenopausal women and men, and it excludes enhancement of sexual performance. It also lists contraindications in uncontrolled hypertension and known cardiovascular disease.
Does Curo have a PT-141 product page?
No. This compound profile is a research reference, not a Curo product listing.