PT-141 (Bremelanotide): Melanocortin Agonist Research Guide (2026)
Last updated
Introduction (research-only scope)
PT-141, generic name bremelanotide, is a synthetic cyclic heptapeptide that acts on melanocortin receptors in the central nervous system. It is one of the few compounds in this catalog whose development reached phase 3 and regulatory approval as a pharmaceutical product. This guide covers the mechanism, the published evidence and how to verify research-grade material.
Research use only. The material described here is a laboratory reagent for in-vitro research by qualified professionals. It is not a medicine, supplement, cosmetic ingredient or veterinary product, is not for human or animal use, and nothing on this page is medical advice or a claim of effect in any person.
What is PT-141?
PT-141 (molecular mass 1025.18, CAS 189691-06-3) is a metabolite-derived analogue of melanotan II, developed after researchers observed effects distinct from pigmentation in the melanotan programme. Unlike melanotan II it is comparatively selective for MC3 and MC4 receptors over MC1. Peptra Labs supplies it as a lyophilised research reagent, 10 mg per vial.
How the reported mechanism works
Central melanocortin receptors
The reported mechanism is agonism at MC3R and MC4R in hypothalamic circuits, a pathway distinct from the vascular mechanism of PDE5 inhibitors. The 2004 PNAS study in female rats is the reference preclinical characterisation of this behavioural pharmacology.
Relationship to melanotan II
Both come from the same melanocortin programme, but their receptor selectivity differs, which is why they are studied for different questions; see Melanotan 2 for the pigmentation-focused analogue.
What the published evidence covers
Bremelanotide has an unusually complete evidence trail for this catalog: preclinical behavioural pharmacology, then two randomised phase 3 trials published in Obstetrics and Gynecology in 2019. Those trials studied a specific formulation of the pharmaceutical product in a defined patient population under medical supervision, and their results describe that product, not research-grade material. For laboratory work the value is the well-mapped receptor pharmacology.
How to verify a PT-141 research peptide is real and pure
Two tests answer two different questions: mass spectrometry confirms identity (expected molecular mass 1025.18), HPLC quantifies purity. Our specification is at least 98%. Check the batch number printed on your vial against the lab reports archive: where a batch has been tested, its report is published there and links to the testing laboratory’s own verification page. If your batch is not listed yet, ask us for its documentation before use; a “typical” certificate is not evidence for a specific vial. See how to read a certificate of analysis.
Storage and reconstitution
Store the lyophilised material sealed, dry and protected from light at 2 to 8 °C for routine laboratory use, colder for long-term archiving. After reconstitution with bacteriostatic water, keep refrigerated and use within the window your protocol defines; repeated freeze-thaw cycles degrade peptides. General handling for all our reagents is in the peptide storage protocol.
Regulatory status
Bremelanotide received United States FDA approval in 2019 for a specific indication under a brand name; that approval attaches to the pharmaceutical product, not to research-grade material, and we make no statement about its current European marketing status, which can be checked in the EMA register. The reagent supplied here carries no marketing authorisation. PT-141 is not named individually on the WADA Prohibited List, but section S0 covers substances without approval for human therapeutic use. Research-grade material supplied here is not a medicine and is for in-vitro laboratory use only. The wider framework, including anti-doping status, is described in the peptide risk profile.
Why labs choose our PT-141
Batch-numbered vials, published reports where a batch has been tested, shipping from an EU warehouse with tracking (no customs inside the EU) and prices shown with VAT included. Product page: PT-141 10 mg. Country-by-country sourcing questions are covered in the buyer guide Buy PT-141 in Europe.
References
- Kingsberg SA et al. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstet Gynecol. 2019. PubMed 31599840
- Pfaus JG et al. Selective facilitation of sexual solicitation in the female rat by a melanocortin receptor agonist. Proc Natl Acad Sci U S A. 2004. PubMed 15226502