CalcMyPeptide
Sexual HealthAlso known as: Bremelanotide, Vyleesi

PT-141

MC4R agonist FDA-approved (Vyleesi) for hypoactive sexual desire disorder in premenopausal women.

Half-Life
~2.7 hours
Dose Range
500-2000 mcg
Frequency
As needed (max 1×/24h, max 8×/month)
Vial Sizes
10 mg

🔬 Mechanism of Action

PT-141 (Bremelanotide) is a synthetic melanocortin receptor agonist that acts on MC4R (melanocortin-4 receptors) in the central nervous system to modulate sexual arousal. Unlike PDE5 inhibitors (Viagra, Cialis) that work peripherally on blood flow, PT-141 works centrally in the brain to enhance desire and arousal.

FDA-approved as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women, PT-141 is also used off-label for male sexual dysfunction. It was originally derived from Melanotan II but engineered to remove the tanning effects while preserving the sexual function pathway.

Source: FDA Label (Vyleesi)

📜Background & History

PT-141 (Bremelanotide) is a cyclic heptapeptide derived from alpha-MSH (alpha-melanocyte-stimulating hormone) developed by Palatin Technologies. Unlike sildenafil and other PDE5 inhibitors that act peripherally, PT-141 acts centrally in the hypothalamus via MC4R (melanocortin-4 receptor) to initiate sexual arousal — making it effective for both men and women. FDA approved in 2019 as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women — the first centrally acting sexual dysfunction treatment approved for women.

🎯 Research Use Cases

  • Female hypoactive sexual desire disorder (HSDD) — FDA approved (Vyleesi)
  • Male erectile dysfunction unresponsive to PDE5 inhibitors
  • Situational or psychogenic sexual dysfunction
  • Research: central arousal pathway modulation

💉 Dosing Protocol

Typical Dose500-2000 mcg
FrequencyAs needed (max 1×/24h, max 8×/month)
Half-Life~2.7 hours
Common Vial Sizes10 mg

🧪 Reconstitution Example

Vial
10 mg
Water
2 mL
Concentration
5 mg/mL
Per Unit (100u syringe)
50 mcg
Dose of 500 mcg = 10 units on a 100-unit insulin syringe

⚠️Safety & Considerations

FDA-approved as Vyleesi. May cause nausea (most common side effect), flushing, and headache. Use maximum 1 dose per 24 hours, maximum 8 doses per month. May cause transient blood pressure elevation. Not recommended for uncontrolled hypertension.

Interactions & Contraindications

Common side effect: transient nausea and flushing (MC1R-mediated). Causes transient blood pressure increase — contraindicated with cardiovascular disease, high blood pressure, or concurrent use of antihypertensives. Do not combine with PDE5 inhibitors (sildenafil, tadalafil) without medical clearance — additive blood pressure reduction risk. Maximum dosing frequency: once per 24 hours.

🔗Synergies & Common Stacks

+ Kisspeptin

Kisspeptin modulates GnRH/LH/FSH upstream of testosterone; PT-141 acts on downstream arousal circuitry. Together they address both hormonal and neurological dimensions of sexual function.

+ Oxytocin

Oxytocin enhances emotional bonding and arousal via different receptors; PT-141 initiates desire centrally. May synergize for comprehensive sexual wellness protocols.

PT-141 dosing guide infographic showing dose range 500-2000 mcg, half-life ~2.7 hours, and reconstitution example
PT-141 dosing quick reference — 500-2000 mcg, As needed (max 1×/24h, max 8×/month)

Frequently Asked Questions

How quickly does PT-141 work?
PT-141 typically takes 45-60 minutes to take effect when injected subcutaneously. Effects last 6-12 hours. Inject approximately 1 hour before anticipated need.
What is the PT-141 dose?
FDA-approved dose (Vyleesi): 1.75 mg subcutaneously. Research protocols range from 500 mcg to 2,000 mcg. Start with a lower dose to assess tolerance, particularly for nausea.
Can men use PT-141?
Yes — while Vyleesi is specifically FDA-approved for women with HSDD, PT-141 is used off-label by men for erectile dysfunction. It works through a different mechanism than Viagra/Cialis (central vs peripheral) and may benefit men who don't respond to PDE5 inhibitors.

📖 References

  1. Kingsberg SA, et al. Bremelanotide for treatment of hypoactive sexual desire disorder (RECONNECT).” Obstet Gynecol (2019). PMID: 31135742
  2. Rosen RC, et al. Melanocortin receptor agonists for the treatment of sexual dysfunction.” J Sex Med (2004). PMID: 15497047

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