PT-141, known by its generic name bremelanotide, is one of the few peptides that went from a research compound to an FDA-approved drug. It’s also unusual because it works on desire in the brain, not blood flow. Here’s the full story, the FDA-labeled dosing, and the side effects to know about.
Key takeaways
- Bremelanotide came out of research on melanotan II, a peptide originally studied for tanning.
- It activates melanocortin receptors in the brain, mainly MC4R.
- The FDA approved it in 2019 as Vyleesi for premenopausal women with HSDD.
- Nausea is the most common side effect. It can also temporarily raise blood pressure.
From tanning research to a sexual health drug
In the 1980s, researchers at the University of Arizona developed melanotan peptides to stimulate skin tanning as a possible way to reduce skin cancer risk. During testing of melanotan II, volunteers reported an unexpected effect: increased sexual arousal.
That led to the development of bremelanotide, a related peptide designed to focus on the sexual response. Early versions were studied as a nasal spray, but development moved to an under-the-skin injection, partly because of blood pressure effects seen with the nasal form.
How PT-141 works
Drugs like sildenafil (Viagra) work by increasing blood flow. Bremelanotide works differently. It activates melanocortin receptors, especially MC4R, in areas of the brain involved in sexual desire and arousal. That’s why it was developed for low desire rather than erectile function.
FDA approval: Vyleesi
In 2019 the FDA approved bremelanotide as Vyleesi for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD). That means low sexual desire that causes distress and isn’t caused by another medical or psychiatric condition, a medication, or problems in the relationship.
In the phase 3 RECONNECT trials, women using bremelanotide reported modest but statistically significant improvements in desire and reductions in distress compared with placebo.
FDA-labeled dosing (Vyleesi)
| Dose | 1.75 mg by subcutaneous injection (prefilled autoinjector) |
|---|---|
| Where | Abdomen or thigh |
| When | At least 45 minutes before anticipated sexual activity |
| Limit | No more than 1 dose in 24 hours |
| Monthly limit | No more than 8 doses per month |
| Reassess | Stop if there’s no improvement after 8 weeks |
Follow the current prescribing information and your prescriber’s guidance.
Side effects
- Nausea: the most common side effect, most often with the first dose, and it tends to lessen with later doses
- Flushing
- Headache
- Injection-site reactions
- Temporary blood pressure increase and lower heart rate after each dose, which usually return to normal within about 12 hours
- Skin darkening (hyperpigmentation) on the face, gums or breasts in a small percentage of users, more likely with frequent use; it may not fully go away
Who should not use it
The label says not to use it with uncontrolled high blood pressure or known cardiovascular disease. It can also lower levels of oral naltrexone, which matters for people taking naltrexone for alcohol or opioid use disorder.
What about PT-141 for men?
Bremelanotide has been studied in men, including men with erectile dysfunction who didn’t respond to sildenafil. It is not FDA-approved for men. Products marketed as “PT-141” online for men are either off-label prescriptions or research-use-only products.
PT-141 vs melanotan II
| PT-141 (bremelanotide) | Melanotan II | |
|---|---|---|
| FDA status | Approved as Vyleesi (women, HSDD) | Not approved |
| Main target | MC4R (desire) | Several melanocortin receptors (tanning, appetite, arousal) |
| Tanning effect | Minimal, but hyperpigmentation possible | Strong |
Related: What are peptides? · Compound Library
Frequently asked questions
What is PT-141 used for?
Bremelanotide (PT-141) is FDA-approved as Vyleesi for premenopausal women with hypoactive sexual desire disorder (low sexual desire that causes distress).
How long before PT-141 works?
The Vyleesi label says to inject at least 45 minutes before anticipated sexual activity.
Is PT-141 approved for men?
No. It has been studied in men but is only FDA-approved for premenopausal women with HSDD.
What are the side effects of PT-141?
The most common is nausea. Others include flushing, headache, injection-site reactions, a temporary rise in blood pressure, and skin darkening in some users.
Medical disclaimer: Pep Guide is for educational purposes only. It is not medical advice, diagnosis or treatment. Research changes over time. Talk to a licensed healthcare provider before starting, stopping or changing any medication or compound.