Last updated: March 2026
Bremelanotide • Melanocortin Receptor Agonist for Sexual Health
PT-141 (Bremelanotide) is a synthetic peptide hormone originally developed from Melanotan II. Unlike its predecessor, PT-141 was specifically designed to target sexual dysfunction without the unwanted tanning effects. The peptide works as a melanocortin receptor agonist, specifically targeting the MC3R and MC4R receptors in the brain.
PT-141 represents a breakthrough in sexual health treatment because it acts centrally through the nervous system rather than affecting blood flow like traditional treatments. This makes it effective for both physiological and psychological aspects of sexual dysfunction.
In June 2019, the FDA approved Vyleesi (bremelanotide injection) for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women. This marked a significant milestone as only the second FDA-approved treatment for female sexual dysfunction.
The approval was based on two large Phase 3 trials (RECONNECT studies) involving over 1,200 women with HSDD. Participants showed statistically significant improvements in sexual desire and reduction in distress related to low sexual desire.
PT-141 activates melanocortin receptors (primarily MC3R and MC4R) in the hypothalamic areas of the brain associated with sexual arousal. This central nervous system approach differs significantly from PDE5 inhibitors like Viagra, which work peripherally on blood vessels.
The melanocortin system regulates various physiological functions including appetite, inflammation, and sexual behavior. PT-141's selectivity for certain melanocortin receptors allows it to enhance sexual function while minimizing effects on pigmentation and appetite that were problematic with earlier compounds.
PT-141 dosing varies significantly between FDA-approved pharmaceutical use and research applications. The timing and frequency are critical factors for optimal results.
| Protocol | Dose | Timing | Frequency | Maximum |
|---|---|---|---|---|
| FDA (Vyleesi) | 1.75mg | 45 min before | As needed | Once per 24h, 8x/month |
| Research (Low) | 0.5-1.0mg | 45-60 min before | As needed | 2-3x per week max |
| Research (Standard) | 1.0-1.5mg | 45-60 min before | As needed | 2-3x per week max |
| Research (High) | 1.5-2.0mg | 45-60 min before | As needed | 2x per week max |
PT-141 typically comes as lyophilized powder in 10mg vials. Proper reconstitution is essential for maintaining peptide stability and achieving accurate dosing.
PT-141 is designed for subcutaneous injection, typically in the abdomen or thigh. Proper injection technique ensures optimal absorption and minimizes side effects.
PT-141's side effect profile is well-documented from clinical trials. Nausea is the most common side effect, occurring in approximately 40% of users at therapeutic doses.
| Side Effect | Frequency | Severity | Duration |
|---|---|---|---|
| Nausea | ~40% | Mild to Moderate | 2-8 hours |
| Flushing | ~20% | Mild | 1-4 hours |
| Headache | ~15% | Mild | 2-6 hours |
| Injection site reaction | ~10% | Mild | 24-48 hours |
PT-141 has been extensively studied in clinical trials, primarily focusing on female sexual dysfunction, though research in males has also shown promise.
While not FDA-approved for male use, several studies have investigated PT-141's effects in men with erectile dysfunction, showing promising results particularly in men with psychogenic ED.
Understanding how PT-141 compares to other sexual health treatments helps inform treatment decisions.
| Treatment | Mechanism | Onset | For Women | For Men |
|---|---|---|---|---|
| PT-141 | CNS (brain) | 45-120 min | FDA approved | Off-label |
| Viagra/Cialis | Vascular (blood flow) | 30-60 min | Limited efficacy | FDA approved |
| Flibanserin | Neurotransmitter | Daily dosing | FDA approved | Not indicated |
| Testosterone | Hormonal | Days to weeks | Off-label | FDA approved |
Proper storage is crucial for maintaining PT-141's potency and safety throughout its shelf life.
| Form | Temperature | Duration | Notes |
|---|---|---|---|
| Lyophilized powder | 2-8°C (refrigerated) | 2+ years | Keep in original packaging |
| Lyophilized powder | Room temperature | 6+ months | Keep dry and dark |
| Reconstituted | 2-8°C (refrigerated) | 4-6 weeks | Use bacteriostatic water |
| Reconstituted | Frozen (-20°C) | 6+ months | Single-use aliquots recommended |
PT-141 typically begins working 45 minutes to 2 hours after injection, with peak effects occurring 2-6 hours post-administration. The duration is highly variable, ranging from 6-72 hours depending on the individual.
No, PT-141 should not be used daily. The FDA recommends maximum once per 24 hours and no more than 8 doses per month for Vyleesi. Research protocols typically suggest 2-3 times per week maximum to avoid tolerance and minimize side effects.
Yes, clinical studies show PT-141 is effective for men, particularly those with psychogenic erectile dysfunction or those who don't respond well to PDE5 inhibitors. However, it's not FDA-approved for male use.
PT-141 was developed from Melanotan II but with modifications to reduce tanning effects and focus on sexual function. PT-141 has much less effect on pigmentation while maintaining sexual enhancement properties.
Yes, nausea can often be managed by starting with lower doses, taking anti-nausea medication beforehand, avoiding empty stomach injection, and staying well-hydrated. Some users find taking it at bedtime helps sleep through the nausea period.
PT-141 as a research peptide exists in a legal grey area - available for research purposes but not approved for human consumption. Vyleesi (pharmaceutical PT-141) is FDA-approved and available by prescription for women with HSDD.
Research PT-141 typically costs $50-150 per 10mg vial depending on source and quality. Vyleesi (prescription) costs approximately $400+ per month without insurance coverage.
Use our calculator above to determine exact injection volumes for your protocol.
Back to Calculator ↑Bacteriostatic water, insulin syringes, and alcohol swabs for your research.
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