PT-141, or bremelanotide, is a peptide that increases sexual desire by acting on the brain, not on blood flow. It is approved in the United States (as Vyleesi) for premenopausal women with low sexual desire, but not in Canada.
- Works on desire and arousal; Viagra and Cialis work on blood flow.
- The approved US dose is 1.75 mg under the skin, at most once in 24 hours.
- Nausea is common, and it briefly raises blood pressure.
Most sexual health medicines for men treat the mechanics of an erection. PT-141 is different: it targets the brain circuits involved in desire. That makes it interesting for people whose problem is low interest rather than physical function, and it explains both its effects and its side effects.
Where PT-141 came from
PT-141 grew out of research on melanotan II, a tanning peptide. Volunteers in early melanotan trials reported unexpected sexual arousal and erections. Researchers then developed bremelanotide, a close relative that keeps the sexual effect with less tanning. It acts on melanocortin receptors (mainly MC4R) in the hypothalamus, an area of the brain that helps control sexual motivation.
How it differs from Viagra and Cialis
| PT-141 | Sildenafil (Viagra) / tadalafil (Cialis) | |
|---|---|---|
| Where it acts | Brain (desire and arousal) | Blood vessels in the penis |
| Needs sexual stimulation? | Increases interest itself | Yes, it only helps the erection |
| How it is taken | Injection under the skin | Tablet |
| Status in Canada | Not approved | Prescription drugs, generics available |
For men whose main problem is erections, PDE5 inhibitors such as Cialis and Viagra are well studied and widely prescribed in Canada. PT-141 has been studied in men for erectile dysfunction, but its approval is for women’s low desire.
What the research shows
Bremelanotide was approved by the US Food and Drug Administration in 2019 after two large trials (RECONNECT) in premenopausal women with hypoactive sexual desire disorder. Women using it reported modest but meaningful increases in desire and less distress about low desire than those on placebo. It did not significantly increase the number of satisfying sexual events, which shows the effect is real but not dramatic.
Side effects
- Nausea: about 40% of women in the trials, usually with the first dose, and sometimes vomiting
- Flushing of the face and chest
- Headache
- Injection-site reactions
- Darkening of the skin on the face, gums or breasts, mainly with frequent use (it is related to a tanning peptide)
- A temporary rise in blood pressure and lower heart rate for up to 12 hours after a dose
Low desire: look for the cause
Low libido is very often a symptom of something treatable. Before trying any sexual health compound, it is worth checking:
- Hormones: low testosterone, high prolactin, or estradiol out of range. Men using anabolic steroids should read our guides on estrogen management and prolactin.
- Medications: some antidepressants (SSRIs), finasteride and blood pressure drugs reduce desire.
- Thyroid problems, sleep apnea, depression and stress.
- Relationship factors, which a counsellor or sex therapist can help with. Many Canadian provinces list registered therapists through their professional colleges.
A simple blood panel through your family doctor, or privately at LifeLabs or Dynacare, rules out the common hormonal causes.
Handling a research vial
PT-141 sold for research arrives as freeze-dried powder. Like other peptides, it is mixed with bacteriostatic water, kept in the fridge at 2–8 °C after mixing, and drawn with a fresh insulin syringe each time; our reconstitution guide walks through the steps. Because nausea is the most common reason people stop, the trials found it eased with later doses, and the US label allows an anti-nausea medicine to be considered with a doctor’s advice.
Legal status in Canada
Bremelanotide is not approved by Health Canada, so Vyleesi is not sold in Canadian pharmacies. Versions sold online are research products. Sildenafil and tadalafil remain the approved first-line options for erectile dysfunction in Canada.
Frequently asked questions
Does PT-141 work for men?
It has been studied in men and can increase arousal and erections, but its approval in the US is for premenopausal women with low sexual desire.
How long does PT-141 take to work?
The US label says to inject it at least 45 minutes before sexual activity. Effects can last several hours.
Can PT-141 be taken with Cialis?
Both affect blood pressure in different ways, so combining them should only be done with medical advice.
Photo: Paul García Fotografía, StockSnap (public domain).
General information, not medical advice. Bremelanotide is not approved in Canada. Speak to a doctor about low libido or erectile problems.
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