What Is PT-141 (Bremelanotide)?
PT-141, generically known as Bremelanotide, is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (α-MSH) that acts as a non-selective melanocortin receptor agonist. It is FDA-approved since 2019 under the brand name Vyleesi for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women — making it one of a small number of research peptides with full regulatory approval and a rigorously characterized clinical profile.
PT-141’s mechanism is fundamentally different from other compounds studied in sexual function research. Rather than acting on the vascular system like PDE5 inhibitors (sildenafil, tadalafil), PT-141 acts centrally through the melanocortin system in the brain, activating MC4R receptors in the hypothalamus and limbic areas to modulate sexual desire and arousal at the neurological level.
PT-141 Mechanism of Action
- MC4R agonism (primary): Activation of melanocortin-4 receptors in the hypothalamus, paraventricular nucleus, and limbic system modulates the neural circuits governing sexual motivation and arousal — the CNS mechanism responsible for its approved indication
- MC1R agonism: Activates melanocyte-stimulating activity, producing transient skin darkening (the same mechanism as Melanotan 2, from which PT-141 was derived)
- MC3R activity: Involved in energy homeostasis and feeding behavior regulation, relevant to metabolic research applications of melanocortin receptor biology
- Central vs. peripheral action: Unlike vascular erectile function compounds, PT-141’s action is primarily CNS-mediated, crossing the blood-brain barrier and activating hypothalamic circuits — a mechanistically distinct research target
PT-141 Research and Clinical Data
- FDA approval trials (HSDD in women): Phase 3 trials (RECONNECT studies) demonstrated statistically significant improvements in satisfying sexual events (SSEs) per month, sexual desire scores, and distress scores on validated instruments compared to placebo in premenopausal women with HSDD
- Male sexual dysfunction research: Phase 2 studies in men with erectile dysfunction demonstrated PT-141 produced erectile responses in a dose-dependent manner, including in men who did not respond to sildenafil — supporting the distinct CNS mechanism hypothesis
- Melanocortin receptor biology: PT-141’s well-characterized receptor binding profile (MC1R, MC3R, MC4R, MC5R) makes it a useful pharmacological tool for studying individual melanocortin receptor contributions in research models
PT-141 Dosage Reference
| Research Context | Dose (Published) | Route |
|---|---|---|
| FDA-approved HSDD dose (clinical) | 1.75mg per use | Subcutaneous auto-injector |
| Phase 2 male ED studies | 4–20mg (intranasal, earlier formulation) | Intranasal |
| Melanocortin receptor research (in vitro) | Nanomolar range | Cell culture |
Published clinical trial data provided for research reference only. Not dosing guidance for human use.
Side Effects from Trial Data
- Nausea — most common adverse event in FDA approval trials (~40% of subjects, mostly mild/moderate)
- Flushing and hot flashes (melanocortin-mediated)
- Transient blood pressure increase (usually resolves within 12 hours)
- Hyperpigmentation with repeated use (MC1R-mediated)
- Headache in some subjects
PT-141 vs. Melanotan 2 — Research Comparison
| Parameter | PT-141 (Bremelanotide) | Melanotan 2 |
|---|---|---|
| Regulatory status | FDA-approved (Vyleesi) | Research only |
| Receptor profile | MC1R, MC3R, MC4R, MC5R | MC1R, MC3R, MC4R, MC5R (similar) |
| Structure | Cyclic heptapeptide | Cyclic heptapeptide (parent compound) |
| Tanning effect | Less prominent | Prominent (higher MC1R activity) |
| Clinical data depth | Phase 3 + post-marketing | Limited formal trials |
Where to Buy PT-141 for Research
Key supplier criteria for PT-141 research material:
- HPLC purity ≥99% with batch certificate
- MS/MS verification of cyclic peptide structure
- Independent third-party COA
- Lyophilized format for stability
Core Power Peptides supplies PT-141 (Bremelanotide) 10mg at ≥99% purity, HPLC and MS/MS verified per batch, with third-party COA available on request.
Research Disclaimer: All information on this page is for educational and scientific reference purposes only. PT-141/Bremelanotide is FDA-approved only for HSDD in premenopausal women (Vyleesi). All other research applications described are investigational. This product is sold for in vitro research and laboratory use only. Not for human consumption. Not medical advice.