What Is It?
A 7-amino-acid cyclic peptide, refined from Melanotan II. FDA-approved June 2019 under the brand name Vyleesi for premenopausal women with hypoactive sexual desire disorder (HSDD).
How Does It Work?
1980s. University of Arizona. Scientists are designing alpha-MSH analogs to make people tan without sunlight. One researcher accidentally doses himself with twice the amount of Melanotan II. He gets a tan. He also gets an 8-hour erection. Twenty years later, that side effect becomes Vyleesi — and an FDA approval. Works as an MC4R agonist in the hypothalamus — central desire activation via dopamine modulation. Brain-based, not vascular (fundamentally different from Viagra/Cialis).
Primary Benefits (research suggests)
- Central, brain-based desire activation (unique mechanism vs PDE5 inhibitors)
- Only FDA-approved alpha-MSH analog
- On-demand use with 45-min onset and a 4-6 hour window
Run the Numbers
Calculate your PT-141 reconstitution — BAC water volume, syringe units, and draw amounts. Free, no login required.
Open the Calculator →The Honest Part
- FDA-approved but with real cautions — cardiovascular contraindication (uncontrolled hypertension, known CV disease).
- Transient blood-pressure increase after dose.
- 40% nausea rate in Phase 3 trials.
- Hyperpigmentation with more than 8 doses/month (may not resolve).
- Off-label use in men is not FDA-approved.
- For research purposes only when discussing non-approved uses.
Research Sources
Verified vendors offering this compound for research purposes. Use code ROCN10 for discounts. We may earn commissions from these links.
Track PT-141 in the App
Peptide Manager Pro tracks 100+ compounds with an interactive knowledge graph, dosing calculator, protocol tracker, and AI research chat. Veteran-owned. $4.99/mo founding rate.
Get the App →