PT-141
FDA-approved melanocortin agonist for hypoactive sexual desire disorder — acts centrally on the brain, not the vascular system.
Research facts
| Half-life | ~2.7h |
|---|---|
| Route | SubQ / Nasal |
| Typical dose | 1.75 mg SubQ (FDA) / 0.75–2 mg experimental |
| Frequency | 45–60 minutes before activity (not more than once every 24h) |
| Solvent | Bacteriostatic water |
| pH | 5.0–7.0 |
| Stability | 30 days at +4°C |
Mechanism of action
PT-141 (bremelanotide) is a cyclic heptapeptide analogue of alpha-MSH, developed from the tanning peptide Melanotan II. It selectively activates melanocortin receptors 3 and 4 (MC3R, MC4R) in the CNS, particularly the medial preoptic area and hypothalamus. This central mechanism drives sexual arousal in both men and women by modulating dopaminergic pathways — distinct from PDE5 inhibitors (Viagra/Cialis) which work peripherally via vascular smooth muscle. FDA-approved as Vyleesi (intranasal 1.75mg) for pre-menopausal women with hypoactive sexual desire disorder (HSDD). Subcutaneous administration produces faster onset and potentially stronger effect but is off-label.
Documented effects (research-model)
- FDA-approved treatment for HSDD in pre-menopausal women
- Central (brain) mechanism — works on desire, not just blood flow
- Effective in men for ED and libido (off-label, Phase II data)
- Works independently of oestrogen levels (post-menopause research)
- No cardiovascular mechanism — distinct from PDE5 inhibitors
- On-demand dosing (no daily pill required)
Research protocols
| Protocol | Dose | Frequency | Cycle | Vial |
|---|---|---|---|---|
| Standard (FDA-approved) | 1.75 mg nasal spray | 45 minutes before activity, max once daily | As needed (not daily use) | Pre-filled nasal spray device (Vyleesi) |
| SubQ Research | 0.75–1.5 mg SubQ | 45–60 minutes before activity | As needed | 10mg / 10mL BAC water |
Research context only. Not medical advice. Consult a qualified healthcare professional before any protocol decision.
Synergies
- Kisspeptin-10 MODERATE
Kisspeptin drives LH/FSH-mediated testosterone (hormonal desire); PT-141 drives central dopaminergic arousal. Hormonal + neurological sexual health stack.
Myths & misconceptions
Evidence gaps
- Long-term safety with repeated use beyond 52 weeks not established.
- Nausea is the most common side effect (20–40% of users) — mechanism not fully understood.
- Post-menopausal efficacy data is limited in large RCTs.
Safety notes
FDA-approved drug with well-established safety profile. Common: nausea, flushing, headache. Transient BP increase (avoid in cardiovascular disease, uncontrolled hypertension). Causes transient hyperpigmentation with repeated use. Do not use daily — maximum once per 24h, and limit frequency.
Biomarkers to monitor
Primary-source citations
- PMID 19675482 — Bremelanotide (PT-141) for premenopausal women with female sexual dysfunction (J Sex Med. 2009)
- PMID 30884233 — Bremelanotide for hypoactive sexual desire disorder (N Engl J Med. 2019)
Frequently asked
What is PT-141?
PT-141 (Bremelanotide — Melanocortin Receptor Agonist) is a research compound classified in our library as Tier A — Reproducible human RCT data.. FDA-approved melanocortin agonist for hypoactive sexual desire disorder — acts centrally on the brain, not the vascular system.
What is the evidence tier for PT-141?
We classify PT-141 as Tier A: Reproducible human RCT data. See our full peptide evidence tiers explainer for how we assign S/A/B/C/D.
What is the research dose of PT-141?
For PT-141, typical research dose is 1.75 mg SubQ (FDA) / 0.75–2 mg experimental, route is SubQ / Nasal, half-life is ~2.7h. Protocols vary by research goal — see the protocols section on this page for standard and advanced dosing schedules. Research use only, not medical advice.
Is PT-141 safe?
FDA-approved drug with well-established safety profile. Common: nausea, flushing, headache. Research context only — no compound on this site is approved for human therapeutic use unless explicitly noted.