PT-141
Also known as: Bremelanotide, PT141, Vyleesi
PT-141 (Bremelanotide) is a synthetic melanocortin peptide that acts on the central nervous system to influence sexual arousal. It is the only FDA-approved peptide for hypoactive sexual desire disorder (HSDD) in premenopausal women, marketed as Vyleesi.
PT-141 is a 1,025.18 Da research peptide. PT-141 (Bremelanotide) is a synthetic melanocortin peptide that acts on the central nervous system to influence sexual arousal. It is the only FDA-approved peptide for hypoactive sexual desire disorder (HSDD) in premenopausal women, marketed as Vyleesi.
Also called: Bremelanotide, PT141, Vyleesi
1,025.18
Molecular Weight
Daltons
2
Strong Evidence
benefits
5
Studies Cited
peer-reviewed
1750-1750
Typical Dose
mcg
Overview
PT-141, also known as Bremelanotide, is a cyclic heptapeptide melanocortin receptor agonist originally derived from the tanning peptide Melanotan II. Unlike PDE5 inhibitors (such as sildenafil) which work on the vascular system, PT-141 acts directly on melanocortin receptors (primarily MC3R and MC4R) in the central nervous system to modulate sexual arousal and desire. It was developed by Palatin Technologies and received FDA approval in 2019 under the brand name Vyleesi for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women. PT-141 represents a novel mechanism of action for sexual dysfunction; working through the brain's desire pathways rather than peripheral blood flow. Clinical trials demonstrated statistically significant improvements in sexual desire and reductions in distress related to low sexual desire compared to placebo.
Key Takeaways: PT-141
- Strongest evidence supports PT-141 for female sexual desire (hsdd) and central arousal mechanism
- Research doses typically range from 1750 to 1750 mcg via subcutaneous injection (abdomen or thigh)
- 2 benefits with strong evidence, 2 moderate, 0 preliminary
- Half-life: Approximately 2.7 hours
- 5 cited research studies in this guide
Mechanism of Action
PT-141 functions as a nonselective agonist at melanocortin receptors, with primary activity at MC3R and MC4R subtypes located in the hypothalamus and limbic system. These receptors contributes to regulating sexual behavior, energy homeostasis, and autonomic functions. When PT-141 binds to MC4R in the medial preoptic area and paraventricular nucleus of the hypothalamus, it initiates a signaling cascade that modulates dopaminergic and oxytocinergic pathways involved in sexual arousal and desire. This central mechanism distinguishes PT-141 from vasodilator-based treatments, it influences the motivational and desire components of sexual response rather than the mechanical erectile response. PT-141 also retains some activity at MC1R (involved in melanogenesis) and MC5R, which may contribute to minor side effects like skin flushing and temporary pigmentation changes. The peptide's cyclic structure provides improved metabolic stability compared to its linear predecessor, alpha-MSH.
Research Benefits
PT-141 at a Glance
PT-141 functions as a nonselective agonist at melanocortin receptors, with primary activity at MC3R and MC4R subtypes located in the hypothalamus and limbic system.
Female Sexual Desire (HSDD)
Strong EvidenceFDA-approved for hypoactive sexual desire disorder in premenopausal women. Phase III clinical trials (RECONNECT) demonstrated significant improvement in desire scores and reduction in distress compared to placebo.
Central Arousal Mechanism
Strong EvidenceUnique mechanism acting on brain melanocortin receptors rather than peripheral vasculature. May benefit individuals whose sexual dysfunction has a central/motivational rather than vascular origin.
Male Erectile Function
Moderate EvidencePhase II clinical trials showed PT-141 induced erections in men with erectile dysfunction, including some who did not respond to PDE5 inhibitors. Works through a different mechanism than sildenafil.
Rapid Onset
Moderate EvidenceClinical data shows onset of effect within approximately 45 minutes of subcutaneous injection, with effects lasting up to 24 hours in some studies.
Research Dosing Protocols
Research Purposes Only: All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
| Research Protocol | Dose Range | Route |
|---|---|---|
| FDA-approved dose (Vyleesi, female HSDD) | 1750–1750 mcg | Subcutaneous injection (abdomen or thigh) |
| Male ED research protocols | 1000–2000 mcg | Subcutaneous injection |
| Lower dose research protocols | 500–1000 mcg | Subcutaneous injection |
Frequency
As needed, no more than once per 24 hours
Timing
Approximately 45 minutes before anticipated activity
Cycle Length
As-needed basis; not intended for daily use
Research Notes
- 1The FDA-approved dose for Vyleesi is 1.75 mg (1,750 mcg) subcutaneous, as needed.
- 2Maximum of 1 dose per 24 hours and no more than 8 doses per month (per FDA labeling).
- 3Onset of action is approximately 45 minutes post-injection.
- 4Nausea is the most commonly reported side effect and may be dose-dependent.
- 5PT-141 is not recommended for use in patients with uncontrolled hypertension or cardiovascular disease.
Reconstitution Guide
Standard Reconstitution
Vial Size
10 mg
Bacteriostatic Water
2 mL
Concentration
50 mcg
per 0.1 mL (10 units)
Step-by-Step Guide
Gather Materials
PT-141 vial, bacteriostatic water, alcohol swabs, insulin syringes.
Equilibrate Temperature
Remove the vial from storage and allow it to reach room temperature (5-10 minutes).
Sanitize
Swab the rubber stopper of both the peptide vial and bacteriostatic water vial with alcohol.
Draw Water
Draw 2 mL of bacteriostatic water into a syringe.
Add Water to Vial
Insert the needle into the peptide vial and direct the water stream against the glass wall — not directly onto the powder.
Mix Gently
Swirl the vial gently until the powder is fully dissolved. Never shake. The solution should be clear and colorless.
Store Properly
Refrigerate at Refrigerated (2-8°C / 36-46°F) after reconstitution. Up to 30 days refrigerated after reconstitution.
Storage Temperature
Refrigerated (2-8°C / 36-46°F) after reconstitution
Shelf Life
Up to 30 days refrigerated after reconstitution
Important Notes
- •The FDA-approved product (Vyleesi) comes as a pre-filled single-use autoinjector — no reconstitution needed.
- •Research-grade PT-141 lyophilized powder requires reconstitution with bacteriostatic water.
- •Use standard aseptic technique for reconstitution.
- •Swirl gently to dissolve; do not shake.
- •Solution should be clear and colorless.
PT-141 Dosing Calculator
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PT-141 Reconstitution Calculator
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Safety & Side Effects
Reported Side Effects
- !Nausea (40% in clinical trials, most common side effect, usually transient)
- !Flushing/skin warmth (20%)
- !Injection site reactions (redness, bruising, itching)
- !Headache (11%)
- !Temporary darkening of skin (hyperpigmentation), particularly gums and face
- !Transient blood pressure increase (typically mild, returns to baseline)
- !Vomiting (reported in some subjects, dose-related)
- !Nasal congestion
Potential Interactions
- ⚡Not recommended with other melanocortin receptor agonists (potential additive effects).
- ⚡Caution with antihypertensive medications; PT-141 may cause transient BP elevation.
- ⚡Potential interaction with naltrexone (opioid antagonist) — both affect central pathways.
- ⚡No significant interaction with PDE5 inhibitors in clinical studies, but combination use lacks extensive safety data.
- ⚡Caution in patients taking medications that lower blood pressure due to transient hemodynamic effects.
Important: Side effects and interactions listed here are compiled from published research and community reports. This is not a complete list. No formal drug interaction studies have been conducted for most research peptides. Always consult a qualified healthcare provider.
Research Studies
The following studies are referenced in this profile. PubMed IDs are provided where available for independent verification.
Bremelanotide for Hypoactive Sexual Desire Disorder: RECONNECT Study
key Phase III trial demonstrating that bremelanotide 1.75 mg significantly improved sexual desire and reduced distress related to low desire in premenopausal women with HSDD compared to placebo over 24 weeks.
Melanocortin receptor agonists, penile erection, and sexual motivation
Early clinical study demonstrating that melanocortin agonists (PT-141 precursors) can induce erections in men through central nervous system pathways, establishing proof of concept for the melanocortin mechanism.
Bremelanotide: New Drug for Hypoactive Sexual Desire Disorder
thorough review of bremelanotide clinical development program, pharmacology, efficacy data from RECONNECT trials, and safety profile supporting FDA approval for HSDD.
A double-blind, placebo-controlled study of subcutaneous bremelanotide for male erectile dysfunction
Phase IIb trial showing bremelanotide produced clinically meaningful erectile responses in men with ED, including patients unresponsive to sildenafil, confirming the central mechanism of action.
Melanocortin-4 receptor in sexual function
Elucidated the role of MC4R in sexual function, providing the mechanistic basis for PT-141's activity. Demonstrated that MC4R activation in the hypothalamus drives pro-sexual signaling cascades.
Note: This is not an exhaustive list of all published research. Studies are selected for relevance and quality. Click PubMed IDs to verify sources independently. Inclusion does not imply endorsement of the peptide for any clinical use.
Frequently Asked Questions
PT-141 (Bremelanotide) is a melanocortin receptor agonist peptide that acts on the central nervous system to influence sexual desire and arousal. It is FDA-approved as Vyleesi for treating hypoactive sexual desire disorder (HSDD) in premenopausal women.
PT-141 works on melanocortin receptors in the brain to stimulate sexual desire, while Viagra (sildenafil) works on blood vessels to improve blood flow for erections. PT-141 targets the desire/motivation component; Viagra targets the mechanical/vascular component. They work through completely different pathways.
PT-141 typically begins working within approximately 45 minutes of subcutaneous injection, with peak effects occurring 1-2 hours post-injection. Effects may last up to 24 hours.
Yes. PT-141 (as Bremelanotide/Vyleesi) received FDA approval in June 2019 for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women. It is the first FDA-approved treatment targeting brain pathways for sexual desire.
PT-141 retains some activity at MC1R (melanocortin-1 receptor), which is involved in melanin production. Some users report temporary darkening of the skin, particularly on the face and gums. This effect is generally mild and reversible.
While the FDA approval is specifically for premenopausal women with HSDD, clinical trials in men with erectile dysfunction showed positive results. PT-141 induced erections in men, including some who did not respond to PDE5 inhibitors. However, it is not FDA-approved for male use.
Research & Educational Use Only
All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
The information presented here is compiled from published research studies and is intended for informational purposes only. Individual results may vary. Always consult with a licensed healthcare provider.