PT-141, known scientifically as bremelanotide, is the peptide behind a libido treatment that works on the brain rather than on blood flow. It is used by both men and women for low desire and arousal difficulties. This guide explains what PT-141 is, how it works, how it differs from Viagra-type tablets, what the evidence shows, how it is dosed for men and women, the safety points, and how to start on a doctor-led programme in South Africa.
Everything here was reviewed by Dr Chris van Zyl (registered as M.C. van Zyl, HPCSA MP0287067), who is licensed to both prescribe and dispense medicines under a Section 22C dispensing licence. PT-141 is dispensed on a valid script after a medical questionnaire, with a consultation arranged when your screening calls for one.
What is PT-141 (bremelanotide)?
PT-141 is a small peptide of 7 amino acids that activates melanocortin receptors, mainly the MC3 and MC4 receptors in the brain. These receptors sit in the hypothalamus, the area that regulates sexual desire and arousal. Bremelanotide is the active ingredient of Vyleesi, a prescription medicine in the USA.
How does PT-141 work?
Instead of acting on the blood vessels, PT-141 works on the brain’s own desire pathways. By activating melanocortin receptors it influences the signals that create interest in sex and arousal. That is why it can help when the problem is low desire rather than only the physical response.
How is PT-141 different from Viagra or Cialis?
Viagra and Cialis are PDE-5 inhibitors: they increase blood flow to the penis and only work once a man is already aroused. They do nothing for low desire, and they are not used by women. PT-141 works centrally on desire itself and is used by both men and women. Some men use it when tablets alone have not been enough, under a doctor’s guidance.
What does the evidence show?
The US FDA approved bremelanotide in 2019 as Vyleesi for acquired, generalised low sexual desire in premenopausal women, based on two 24-week trials in more than 1,200 women. The benefit was real but modest: more women on bremelanotide had a meaningful increase in desire than on placebo. Earlier studies also looked at men with erectile dysfunction. It is honest to say it helps some people clearly and others less.
Does PT-141 work for men and women?
Yes. Its approved use is in women, and it is also used by men for low libido and erectile difficulties. The dose differs: on the mobivIVe pen it is usually 15 clicks (1mg) for men and 30 clicks (2mg) for women.
How do I use PT-141?
It is used as needed, injected under the skin of the lower abdomen or thigh about 45 minutes before intimacy. The time to effect varies between people, often a few hours, but stays fairly consistent for the same person, so most people learn their own timing. Never use more than one dose in 24 hours, or more than eight doses a month.
Are there side effects?
The most common is nausea, especially with the first doses, and it usually eases with later doses. Facial flushing or warmth and headache are also common. PT-141 can cause a small, short rise in blood pressure for a few hours after a dose, which settles by itself in healthy people.
Who should avoid PT-141?
PT-141 is not suitable if your blood pressure is not under control or you have heart disease, and women who are pregnant or breastfeeding should not use it. It also reduces the effect of naltrexone, so tell our doctor if you take it. This is why PT-141 is dispensed on a script after a questionnaire and doctor review.
How many doses are in one pen?
One 20mg pen holds 20 doses at the men’s dose (1mg) or 10 doses at the women’s dose (2mg). Because it is used only as needed, one pen usually lasts weeks to months.
How do I get PT-141 in South Africa?
PT-141 is a prescription item, so it starts with a short medical questionnaire that our registered doctor reviews, with a consultation arranged when your screening calls for one. Once a script is issued, your prefilled pen is couriered discreetly anywhere in South Africa with clear dosing instructions. Pricing and the full breakdown are on our PT-141 page.
How to start, in 3 simple steps
- Message us on WhatsApp. Tell our doctor-led team your goal.
- Medical questionnaire. Complete a short questionnaire, reviewed by our registered doctor. A consultation is arranged when your screening calls for one. If it is safe and suitable, a script is issued.
- Delivered to your door. Your prefilled pen is couriered anywhere in South Africa, with clear dosing instructions.
Medically reviewed by Dr Chris van Zyl This guide was written and reviewed by mobivIVe’s medical team, led by Dr Chris van Zyl, an HPCSA-registered medical doctor (registered as M.C. van Zyl, HPCSA reg. no. MP0287067) who is licensed to both prescribe and dispense medicines under a Section 22C dispensing licence. Last reviewed October 2026. Not intended to diagnose, treat, cure or prevent any disease; individual results vary. Consult your healthcare provider.