Vyleesi Side Effects: Nausea, Flushing, Blood Pressure and More
The short answer
Nausea is the most common Vyleesi side effect: 40% of women reported it in the phase 3 trials, compared with 1% on placebo, though it was most frequent after the first dose. Flushing (20%), injection site reactions and headache (11%) were next. Vyleesi also raises blood pressure briefly after each dose and can cause darker patches of skin, especially with frequent use.
What is Vyleesi?
Vyleesi (bremelanotide, often called PT-141) is an injection you give yourself under the skin of the belly or thigh at least 45 minutes before sex, when you want it. It acts on melanocortin receptors in the brain involved in sexual desire. According to its prescribing information, it is FDA-approved for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD), not for women after menopause or for men.
The figures below come from the label’s pooled phase 3 trials, in which 627 women used Vyleesi and 620 used placebo, up to 8 doses a month, for 24 weeks.
How common are Vyleesi side effects?
By the numbers
Most common Vyleesi side effects (Vyleesi vs placebo)
| Side effect | Vyleesi | Placebo |
|---|---|---|
| Nausea | 40.0% | 1.3% |
| Flushing | 20.3% | 0.3% |
| Injection site reactions | 13.2% | 8.4% |
| Headache | 11.3% | 1.9% |
| Vomiting | 4.8% | 0.2% |
| Cough | 3.3% | 1.3% |
| Fatigue | 3.2% | 0.5% |
| Hot flush | 2.7% | 0.2% |
| Tingling or numbness (paresthesia) | 2.6% | 0.0% |
| Dizziness | 2.2% | 0.5% |
| Nasal congestion | 2.1% | 0.5% |
The label describes most side effects as mild (31%) to moderate (40%) and short-lived. A 2022 review of the whole development program, covering about 3,500 people in 43 studies, reached the same conclusion and named nausea as the most common reason people stopped.
Nausea: the side effect most people ask about
Nausea usually started within an hour of a dose and lasted about two hours. It was most likely after the very first dose, reported by 21% of women, and dropped to about 3% after later doses. Thirteen percent of women on Vyleesi took an anti-nausea medicine, and 8% stopped the trials because of nausea. In a separate study, taking ondansetron (a common anti-nausea pill) beforehand did not reduce Vyleesi-related nausea, so talk to your prescriber rather than pre-treating on your own.
Blood pressure and heart rate
Each dose briefly raises blood pressure. The label reports peak increases of about 6 mmHg systolic and 3 mmHg diastolic, two to four hours after the injection, with heart rate falling by up to 5 beats per minute; both usually return to baseline within 12 hours. Because of this, Vyleesi is contraindicated in people with uncontrolled high blood pressure or known cardiovascular disease and is not recommended for people at high cardiovascular risk. Your prescriber should check your blood pressure before you start and from time to time while you use it.
Darker patches of skin (hyperpigmentation)
Vyleesi can cause focal hyperpigmentation, darker patches on the face, gums or breasts. In the phase 3 trials it was reported by 1% of women using up to 8 doses a month, and by none on placebo. In a study of daily dosing, 38% developed it after 8 days in a row. It was more likely in people with darker skin and did not always fade after stopping, which is one reason the label says not to use more than 8 doses a month.
Medicine interactions
Vyleesi may slow stomach emptying, which can reduce how much of some oral medicines is absorbed. The label specifically says to avoid it with naltrexone taken by mouth for alcohol or opioid dependence, and to avoid Vyleesi when taking oral medicines that must reach a certain level in the blood to work, such as antibiotics. Tell your prescriber about everything you take.
How Vyleesi compares with other options
| Option | How it’s used | Most common side effects | FDA status |
|---|---|---|---|
| Vyleesi (bremelanotide) | Injection as needed before sex | Nausea, flushing, headache | FDA-approved for HSDD in premenopausal women |
| Addyi (flibanserin) | Pill every night | Dizziness, sleepiness, nausea | FDA-approved for HSDD in women under 65 |
| Compounded PT-141 products | Nasal spray, troche or tablet, varies by pharmacy | Not studied in the trials above | Compounded, not FDA-approved |
See Addyi side effects, PT-141 vs Addyi and what Vyleesi costs.
Blys is a compounded, rapid-dissolve tablet that combines PT-141 with oxytocin and tadalafil, taken 30 to 60 minutes before intimacy. It is compounded and not FDA-approved, and its PT-141 is not the same product or dose as the Vyleesi injection studied above. Because it contains tadalafil, it must never be used with nitrate medicines. A licensed clinician reviews your health history and medicines and decides whether it is appropriate.
When to call a clinician
Common questions
Does Vyleesi nausea go away?
In the trials, nausea usually began within an hour of a dose and lasted about two hours. It was most common after the first dose (21% of women) and was reported by about 3% after later doses. About 8% of women stopped the trials because of it.
Does Vyleesi raise blood pressure?
Yes, briefly. The label reports peak rises of about 6 mmHg systolic and 3 mmHg diastolic two to four hours after a dose, with a small drop in heart rate, usually back to baseline within 12 hours. It should not be used by people with uncontrolled high blood pressure or known cardiovascular disease.
Can Vyleesi darken your skin?
It can. Focal hyperpigmentation, including on the face, gums and breasts, was reported by 1% of women using up to 8 doses a month, and was more likely with daily dosing and in people with darker skin. It did not always fade after stopping.
Can I take Vyleesi with alcohol?
The Vyleesi label does not have an alcohol restriction like Addyi's. Ask your prescriber about your own situation, including any medicines you take by mouth, because Vyleesi can slow how some oral medicines are absorbed.
Sources
Amie prescribes in all 50 states. Find low libido treatment in your state.