Peptide Medicine
PT-141 (Bremelanotide): How It Works, Uses, and Safety
Medically reviewed by HealthRX.com Medical Team · Last reviewed
What is PT-141?
PT-141 is the peptide bremelanotide, a melanocortin receptor agonist. It is the active ingredient in Vyleesi, an FDA-approved injectable for low sexual desire in some premenopausal women. It is related to melanotan II but is used for sexual function rather than tanning.
Bremelanotide acts on the brain's melanocortin system rather than on blood vessels. That makes it different from PDE5 inhibitors such as sildenafil (Viagra) and tadalafil (Cialis), which work by improving blood flow. [1]
How does PT-141 work?
PT-141 activates melanocortin receptors, mainly MC4R, in areas of the brain involved in sexual arousal. By acting centrally on desire rather than on blood flow, it can affect people whose concern is low desire rather than the physical mechanics of an erection.
Because the mechanism is central, PT-141 is studied in situations where blood-flow drugs are not the right fit, including low desire in women and some men who do not respond to PDE5 inhibitors. [1][2]
What does the research show?
The strongest evidence is in premenopausal women with hypoactive sexual desire disorder. In the phase 3 RECONNECT trials, bremelanotide produced modest but statistically significant improvements in desire and reductions in distress, which led to FDA approval of Vyleesi in 2019. Off-label use in men is less studied.
- Women with HSDD: phase 3 RECONNECT trials showed modest, statistically significant benefits versus placebo. [1]
- Men: smaller studies have looked at libido and erectile function, but the evidence is more limited and use is off-label. [2]
- Honest framing: effect sizes are modest, and Vyleesi is not approved for postmenopausal women or to boost normal sexual function.
How is PT-141 dosed?
Vyleesi is a 1.75 mg subcutaneous injection taken about 45 minutes before anticipated activity, with no more than one dose in 24 hours and no more than eight per month. Compounded PT-141 doses vary and should be directed by a licensed provider.
| Form | Typical use | Notes |
|---|---|---|
| Vyleesi (branded) | 1.75 mg under the skin, about 45 minutes before activity | Max one dose per 24 hours, eight per month |
| Compounded PT-141 | Provider-directed | Doses vary by pharmacy; requires a prescription and oversight |
Is PT-141 safe, and what are the side effects?
The most common side effect is nausea, which affected a large share of people in trials and sometimes needed anti-nausea support. Flushing, headache and injection-site reactions are also common. PT-141 can cause a temporary rise in blood pressure, so it is avoided in uncontrolled hypertension or cardiovascular disease.
- Nausea (common, sometimes significant), flushing and headache. [1]
- Temporary increase in blood pressure with a small drop in heart rate; avoid with uncontrolled high blood pressure or heart disease. [1]
- Focal darkening of the skin (hyperpigmentation) can occur with repeated use.
- Not for use in pregnancy.
Is PT-141 legal and FDA approved?
Yes, in a specific form. Vyleesi (bremelanotide) is FDA approved for premenopausal women with acquired, generalized HSDD. Compounded PT-141 and use in men are off-label and require a prescription. As with all compounded peptides, source quality matters.
How does PT-141 compare with other peptides?
| PT-141 (bremelanotide) | Sildenafil (Viagra) | Tadalafil (Cialis) | |
|---|---|---|---|
| Target | Brain (melanocortin receptors) | Blood flow (PDE5) | Blood flow (PDE5) |
| Main effect | Sexual desire and arousal | Erection support | Erection support |
| Route | Injection | Oral | Oral |
| FDA approved | Yes, for some women (HSDD) | Yes (ED) | Yes (ED) |
Frequently asked questions
Is PT-141 FDA approved?
Bremelanotide is FDA approved as Vyleesi for premenopausal women with acquired, generalized hypoactive sexual desire disorder. Other uses, including in men, are off-label.
Does PT-141 work for men?
Smaller studies have looked at PT-141 for libido and erectile function in men, but the evidence is limited and this use is off-label.
How is PT-141 different from Viagra?
PT-141 acts on the brain to influence sexual desire, while Viagra and similar drugs work on blood flow to support an erection.
What are the main side effects of PT-141?
Nausea is the most common, along with flushing and headache. It can briefly raise blood pressure, so it is avoided in uncontrolled hypertension or heart disease.
How quickly does PT-141 work?
Vyleesi is taken about 45 minutes before anticipated sexual activity.
Citations
- Clayton AH, et al. Bremelanotide for Female Sexual Dysfunctions in Premenopausal Women (RECONNECT). Obstet Gynecol. 2019;134(5):909-917.
- Kingsberg SA, et al. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder. Obstet Gynecol. 2019;134(5):899-908.
This guide is educational and is not a substitute for individualized medical advice. PT-141 is prescription-only and requires evaluation by a licensed provider.