PT-141
Bremelanotide · Vyleesi
The only peptide that works on sexual desire itself — not just the plumbing, but the wanting.
What is PT-141?
PT-141 is genuinely unique in pharmacology. Every other sexual dysfunction treatment (Viagra, Cialis, etc.) works by improving blood flow — the mechanical side of arousal. PT-141 works in the brain, directly activating the neural pathways responsible for sexual desire. It does not just help you perform; it makes you actually want to.
Originally discovered as a byproduct of Melanotan II research (where users kept reporting dramatically increased libido as a side effect), PT-141 was refined and eventually FDA-approved in 2019 as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women. It is one of the very few peptides to actually make it through the FDA approval process.
The experience is different from PDE5 inhibitors. Users describe it as a slow-building warmth and desire that develops over 1-2 hours. It works in both men and women, though it is only officially approved for women.
How Does It Work?
PT-141 is a melanocortin receptor agonist, specifically targeting MC3R and MC4R receptors in the hypothalamus. These receptors sit at the intersection of the melanocortin system and sexual behaviour pathways in the brain. By activating them, PT-141 essentially turns up the volume on the neural circuits responsible for sexual arousal and desire.
This is fundamentally different from vasodilators. Viagra does not create desire — it just ensures blood flow responds to whatever desire exists. PT-141 creates the desire itself, by activating central nervous system pathways that evolved to drive reproductive behaviour.
What Does The Research Say?
Strong clinical evidence from human trials.
Multiple Phase III clinical trials led to FDA approval. The RECONNECT trials showed statistically significant improvement in sexual desire and reduction in distress related to low libido in premenopausal women. Effect size was modest but meaningful.
In men, research shows efficacy for erectile dysfunction — including in patients who do not respond to PDE5 inhibitors, which makes sense given it works through a completely different mechanism. Phase II trials in men with ED showed improvement in erectile function scores.
Reported Dosages
These are dosages reported in research literature and community reports. They are NOT medical recommendations. Always consult a healthcare professional.
FDA-approved dose (Vyleesi): 1.75mg subcutaneous injection, at least 45 minutes before anticipated sexual activity. Maximum once per 24 hours, no more than 8 doses per month.
Research/community doses: 0.5-2mg subcutaneously.
Not for daily use.
These are research dosages; the FDA-approved version requires prescription.
Side Effects & Risks
Nausea (very common — affects ~40% of users), flushing, headache, injection site reactions. Nausea is the main reason people discontinue. Can cause transient blood pressure elevation. Skin hyperpigmentation with repeated use (melanocortin activation). Not recommended for people with uncontrolled hypertension or cardiovascular disease.
Legal Status by Country
Not approved. Available as research chemical.
FDA-approved as Vyleesi (prescription only for women with HSDD). Also available as research chemical.
Not approved by EMA. Research chemical.
Not approved by TGA. Research chemical.
Important Disclaimer
This profile is for educational and research purposes only. It does not constitute medical advice. PT-141 may be regulated or illegal in your jurisdiction. Do not use any compound without consulting a qualified healthcare professional. StackPedia does not sell, supply, or promote the use of any controlled substance.