Molecular data
| Molecular formula | C50H68N14O10 |
|---|---|
| Molecular weight | 1025.18 Da |
| Sequence | Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH |
| Sequence length | 7 residues |
| CAS / identifier | Bremelanotide |
| Physical form | Lyophilized powder |
| Available sizes | 10mg |
How it works
Melanocortin-4 Receptor Activation
PT-141 (bremelanotide) acts as a non-selective melanocortin receptor agonist with high affinity for MC3R and MC4R. Activation of MC4R in the central nervous system is associated with the compound's observed effects on arousal pathways in preclinical and clinical research.
- High-affinity binding at MC3R and MC4R
- Central nervous system activity via hypothalamic pathways
- Distinct mechanism from PDE5 inhibitors (no vascular action)
Hypothalamic Signaling Modulation
Research demonstrates PT-141 acts centrally through hypothalamic and limbic system circuits, influencing dopaminergic and serotonergic pathways. This central mechanism of action distinguishes it from peripherally-acting compounds and is the basis for its FDA-approved clinical indication.
- Modulates dopaminergic neurotransmission
- Acts on hypothalamic arousal circuits
- Distinct from peripheral vascular mechanisms
Cyclic MSH Derivative
PT-141 is a synthetic cyclic analog of alpha-melanocyte stimulating hormone (α-MSH). Its cyclic structure confers metabolic stability and improved receptor selectivity compared to its linear precursor. The compound is derived from Melanotan II via hydrolysis of the cyclic lactam ring.
- Cyclic structure enhances metabolic stability
- Derived from Melanotan II via chemical modification
- Improved selectivity profile vs. linear α-MSH
What the research shows
HSDD Research
Clinical trials demonstrated significant improvement in satisfying sexual events and desire scores in women with hypoactive sexual desire disorder. Basis for FDA approval as Vyleesi in 2019.
Simon et al. 2019
Melanocortin System
Research into MC3R and MC4R signaling cascades, including downstream cAMP production and modulation of hypothalamic neuropeptide systems involved in energy homeostasis and arousal.
Giuliano et al. 2003
Male Sexual Function
Early clinical research explored PT-141's potential in male subjects, with Phase II trials showing dose-dependent erectile responses mediated through central MC4R pathways independent of the NO/cGMP cascade.
Diamond et al. 2004
CNS Mechanism Studies
Investigation of central nervous system melanocortin receptor distribution, downstream signaling via Gs-coupled cAMP pathways, and interaction with dopaminergic reward circuitry in preclinical models.
Hadley & Dorr 2006
Specification
| Chemical Name | Bremelanotide |
|---|---|
| Sequence | Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH |
| Molecular Weight | 1025.18 Da |
| Molecular Formula | C₅₀H₆₈N₁₄O₁₀ |
| Form | Lyophilized powder |
| Purity | ≥99% (HPLC verified) |
| Testing | Third-party HPLC, Mass Spec, Endotoxin |
| Storage (lyophilized) | -20°C for long-term stability |
| Storage (reconstituted) | 2–8°C, use within 30 days |
| Solubility | Water or bacteriostatic water |
| COA | Included with every order |
Frequently asked questions
What is PT-141 (Bremelanotide)?
PT-141, also known as bremelanotide, is a synthetic cyclic heptapeptide and analog of alpha-melanocyte stimulating hormone (α-MSH). It acts as an agonist at melanocortin receptors, particularly MC3R and MC4R. The compound was developed from Melanotan II and later approved by the FDA as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women.
How does PT-141 differ from PDE5 inhibitors like sildenafil?
PT-141 has a fundamentally different mechanism than PDE5 inhibitors (like Viagra/Cialis). PDE5 inhibitors work peripherally by increasing blood flow via the nitric oxide/cGMP pathway. PT-141 acts centrally through melanocortin receptors in the brain's hypothalamic and limbic circuits, modulating dopaminergic neurotransmission associated with arousal and desire — not vascular engorgement.
Is PT-141 FDA approved?
Bremelanotide (the pharmaceutical formulation, Vyleesi) is FDA-approved as of June 2019 for treating HSDD in premenopausal women. Research-grade PT-141 sold here is not the approved pharmaceutical formulation and is intended solely for in vitro research purposes. It should not be used therapeutically.
What receptors does PT-141 bind to?
PT-141 binds to multiple melanocortin receptor subtypes. It has highest affinity for MC4R and MC3R, with lower affinity for MC1R, MC2R, and MC5R. MC4R activation in the hypothalamus is believed to be the primary driver of its effects on arousal-related circuits based on receptor knockout studies and pharmacological profiling research.
What were the Phase III clinical trial findings for bremelanotide?
Phase III trials (RECONNECT studies) enrolled premenopausal women with HSDD. Treatment showed a statistically significant increase in satisfying sexual events per month and significant improvement in distress scores (FSDS-DAO) compared to placebo. The most common adverse events were nausea (40%), flushing (20%), and headache (11%).
How should research-grade PT-141 be stored?
Lyophilized PT-141 should be stored at -20°C for long-term stability and protected from light. Once reconstituted in bacteriostatic water or sterile water, store at 2–8°C and use within 30 days. Avoid repeated freeze-thaw cycles, which can degrade peptide integrity.
Literature
- PubMed Bremelanotide for Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials
- PubMed Melanocortin Receptors and Erection in Men and Animals: Pharmacological Properties and Clinical Applications
- PubMed PT-141: A Melanocortin Agonist for the Treatment of Sexual Dysfunction
- PubMed Melanocortin Peptide Therapeutics: Historical Milestones, Clinical Studies and Commercialization
For laboratory research use only. Not a drug, supplement, or medical product; not for human or animal use. All findings referenced are from published preclinical/laboratory research.