PT-141 Side Effects: Label Data on Nausea, BP and Skin

The most common PT-141 side effects in clinical trials were nausea, flushing, injection site reactions, headache and vomiting. Nausea led the list, reported by 40% of women on bremelanotide versus about 1% on placebo (FDA label, 2019). The label also warns about brief rises in blood pressure and darkening of the skin or gums. These numbers come from premenopausal women using branded Vyleesi injection.

Key takeaways

• Nausea is the most common PT-141 side effect: 40% of women on bremelanotide in phase 3 trials versus about 1% on placebo, most often after the first dose.
• Blood pressure rises briefly after each dose, by up to 6 mmHg systolic and 3 mmHg diastolic, which is why a licensed clinician screens blood pressure and heart health before PT-141.
• Patchy darkening of the face, gums or breasts was uncommon in the main trials, far more frequent with daily dosing in another study, and fading was not confirmed in every case.
• People with uncontrolled high blood pressure or known heart disease should not use PT-141, and the label says to avoid it with oral naltrexone used for alcohol or opioid addiction.
• The data describe premenopausal women using FDA-approved Vyleesi. Compounded PT-141 is not FDA-approved, and the numbers may not transfer to men or to compounded product.

Common PT-141 side effects compared with placebo

The label's most common adverse reactions, meaning those above 4%, are nausea, flushing, injection site reactions, headache and vomiting (current FDA labeling, 2026). Each was more frequent on the drug than on placebo, an inactive injection given for comparison.

These rates come from the phase 3 trials. In those trials, 627 women received bremelanotide and 620 received placebo (FDA label, 2019).

Flushing means warmth and redness of the face or neck. The label reports no serious flushing cases. Injection site reactions were also common on placebo, which was given by injection too.

Two numbers matter more than any single side effect:

• Stopping because of side effects: 18% on bremelanotide versus 2% on placebo.
• Serious adverse reactions: 1.1% versus 0.5%.

One headache was serious enough to lead to hospitalization (FDA label, 2019).

Whose data are these, and do they apply to compounded PT-141?

Nearly every PT-141 side effect figure online traces back to the Vyleesi label. The label is built on trials in premenopausal women. Its numbers describe the branded product in that group, not men and not compounded PT-141.

The evidence base is two identical 24-week randomized, double-blind, placebo-controlled phase 3 trials, known as RECONNECT. They enrolled 1,247 premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD), which means persistently low sexual desire that causes distress. A 52-week open-label extension followed, in which 684 women received the drug. Open-label means everyone knew they were on the active drug (FDA label, 2019; Obstet Gynecol, 2019).

• Age: participants were 19 to 56, with a mean age of 39.
• Race: 86% were White and 12% Black.
• Use: most used the drug two to three times a month.
• Funding: the trials were funded by the drug's developers (Obstet Gynecol, 2019).
• Completion: the long-term report notes that about a third of randomized women did not complete the core phase. No deaths occurred across the program (Obstet Gynecol long-term report, 2019).

Vyleesi (bremelanotide) is FDA-approved only for acquired, generalized HSDD in premenopausal women. The label states it is not indicated in men or postmenopausal women, and not indicated to enhance sexual performance. Safety data in men are more limited. This article reviews the 2019 label. Current labeling still lists the same warnings (current FDA labeling, 2026).

Compounded PT-141 has the same active ingredient as Vyleesi (bremelanotide), but compounded medications are not FDA-approved. They are prepared by state-licensed 503A compounding pharmacies or FDA-registered 503B outsourcing facilities. Our compounding disclosure explains the difference between the two. The label describes the branded drug's known effects in one population. It is not safety data on any compounded product. For questions about product quality, see how to read a PT-141 certificate of analysis.

Why does PT-141 cause nausea?

The label does not name a specific cause for nausea. It describes when nausea happens and how long it lasts.

Bremelanotide is a nonselective melanocortin receptor agonist. That means it switches on several receptors in a family that responds to melanocortin hormones. Two receptors matter most. MC4R is found on nerve cells in many areas of the central nervous system. MC1R is found on pigment cells. The label states that the mechanism for HSDD is unknown (FDA label, 2019). Vendor pages that pin nausea on one brain region are going beyond the label.

The pattern in the label:

• Nausea typically started within an hour of a dose and lasted about two hours (median values).
• 21% reported it after the first dose, falling to about 3% after later doses.
• 13% received an anti-nausea medicine, and 8% left the trials because of nausea.

PT-141 works on the nervous system rather than blood flow. It is not a PDE5 inhibitor, the class that includes tadalafil, which must never be combined with nitrate medications. The PT-141 vs tadalafil comparison covers that difference. The PT-141 mechanism guide covers how the drug works.

This article gives no pre-dose tricks. Nausea that is severe or doesn't go away is something to raise with your clinician. Whether anti-nausea treatment makes sense, or whether to stop, is a clinical decision.

Does PT-141 raise blood pressure or affect the heart?

Yes, briefly. After each dose, blood pressure rose and heart rate fell slightly, and both usually returned to baseline within 12 hours.

Blood pressure is measured in mmHg (millimeters of mercury). Systolic is the top number and diastolic the bottom. The label reports the following (FDA label, 2019):

• Maximum rise: up to 6 mmHg systolic and 3 mmHg diastolic, peaking 2 to 4 hours after a dose.
• Heart rate: down by up to 5 beats per minute.
• Recovery: both usually back to baseline within 12 hours.

Some pages quote larger or longer-lasting figures. Check any such figure against the label itself.

An open-label study used ambulatory monitoring, meaning a wearable cuff that records blood pressure through the day. It followed 127 women dosed daily (FDA label, 2019). After 8 days, mean daytime systolic pressure was up 1.9 mmHg and diastolic up 1.7 mmHg. Daily dosing was part of that study's design.

The label lists two contraindications: uncontrolled hypertension and known cardiovascular disease. It does not recommend the drug for people at high cardiovascular risk. It asks prescribers to consider cardiovascular risk before starting and periodically afterward, and to make sure blood pressure is well controlled. This is why a licensed clinician screens blood pressure and heart health before PT-141.

Because each dose raises blood pressure for a period of time, how often PT-141 is used matters. Frequency is set by your clinician's guidance and pharmacy instructions, not by a vendor chart.

Can PT-141 darken your skin or gums?

Yes. Bremelanotide can cause focal hyperpigmentation, meaning patches of darker skin. It was reported on the face, gums (gingiva) and breasts.

• Phase 3 trials: it occurred in 1% of patients on the drug and in no placebo patients.
• Daily dosing study: in a separate clinical study, 38% developed it after 8 consecutive daily doses, and an additional 14% after 8 more days.
• Who is more affected: it was more likely in people with darker skin.
• Reversibility: resolution was not confirmed in every patient (FDA label, 2019).

The cause is better understood than nausea. Bremelanotide activates MC1R on melanocytes, the cells that make pigment, and the label links this to pigmentation. Tell your clinician about any new skin or gum changes. Whether to continue is a clinical decision.

Who should not use PT-141: contraindications and interactions

People with uncontrolled high blood pressure or known heart disease should not use PT-141. Several medication and health situations also need a clinician's judgment (FDA label, 2019).

• Contraindicated: uncontrolled hypertension or known cardiovascular disease.
• Not recommended: high cardiovascular risk.
• Oral naltrexone: the label says to avoid it alongside oral naltrexone used for alcohol or opioid addiction.
• Time-sensitive oral medicines: bremelanotide may slow gastric emptying, the speed at which the stomach passes contents into the intestine. This can reduce how much of an oral drug is absorbed and how fast. The label advises avoiding it with oral drugs that must reach a threshold level to work, such as antibiotics. It also notes that indomethacin, a pain reliever, may take effect more slowly.
• Pregnancy: the label advises effective contraception and stopping if pregnancy is suspected. If you are breastfeeding, raise it with a clinician.
• Severe kidney or liver impairment: use with caution and clinician judgment.
• Liver: one case of acute hepatitis (liver inflammation) occurred in the open-label extension. Bremelanotide's role could not be excluded.

New Blue serves adults 21 and older only. Not everyone qualifies. Eligibility depends on your intake and clinical review, and that's how it should work.

When to call a clinician, and when to get emergency care

Contact your clinician for symptoms that are persistent, new or tied to a medication change. Call 911 for anything that affects breathing, consciousness or the chest.

Contact your clinician promptly for:

• nausea or vomiting that is severe or doesn't go away
• any new darkening of your skin or gums
• suspected pregnancy
• starting oral naltrexone, or an oral medicine that needs to work on time, such as an antibiotic
• severe headache, dizziness or blurred vision, which can be signs of high blood pressure

Call 911 for:

• swelling of the face, lips, tongue or throat
• trouble breathing or swallowing
• hives that spread quickly
• fainting
• chest pain

New Blue is not for emergencies.

How access works through New Blue

PT-141 through New Blue starts with an asynchronous intake that a licensed clinician reviews. A prescription is issued only if appropriate.

1. You complete a structured online intake covering your health history, medications, blood pressure and heart history.
2. A licensed clinician reviews it, including your blood pressure, heart health and medications such as naltrexone. Some treatments or states may require a live visit. Consultation timing varies by clinician availability.
3. If prescribed, a licensed partner pharmacy ships the medication directly to you. PT-141 through New Blue is injectable only. Use follows your clinician's guidance and pharmacy instructions.

Availability varies by state. Check state availability before starting. For current pricing, see the PT-141 treatment page. If treatment isn't appropriate, refunds follow our refund policy.

New Blue is LegitScript certified. New Blue is a technology and administrative services platform. Medical services are provided by independent licensed clinicians; medications are dispensed only if prescribed.

Frequently Asked Questions

Does PT-141 nausea go away with continued use?

In the Vyleesi trials, nausea was most common after the first dose, reported by 21% of women. It fell to about 3% after later doses. It can still occur with continued use. Persistent or severe nausea should be discussed with your clinician.

Does PT-141 make you tan?

PT-141 can cause patches of darker skin, called focal hyperpigmentation, on the face, gums or breasts. The label links this to bremelanotide activating MC1R on pigment cells. It affected 1% of women in phase 3 trials and 38% after 8 consecutive daily doses in another study. The label notes that fading was not confirmed in every patient.

Has PT-141 been studied in men?

Vyleesi is not indicated in men, and its label safety numbers come from premenopausal women aged 19 to 56. Safety data in men are more limited. Side effect rates in men may differ from those on the label.

Does PT-141 affect the heart?

PT-141 causes a short-lived rise in blood pressure, up to 6 mmHg systolic and 3 mmHg diastolic, and a heart rate drop of up to 5 beats per minute. Both usually return to baseline within 12 hours. It is contraindicated in uncontrolled hypertension and known cardiovascular disease. A licensed clinician screens blood pressure and heart health before PT-141.

What is the regulatory status of compounded PT-141?

Compounded PT-141 is not FDA-approved. It has the same active ingredient as Vyleesi (bremelanotide) and is prepared by state-licensed 503A compounding pharmacies or FDA-registered 503B outsourcing facilities. Vyleesi itself is FDA-approved only for acquired, generalized HSDD in premenopausal women.

Can you use PT-141 while taking naltrexone?

The Vyleesi label says to avoid bremelanotide with oral naltrexone products used for alcohol or opioid addiction. Tell your clinician about every medication you take during intake, including naltrexone.

Sources

1. VYLEESI (bremelanotide injection), for subcutaneous use: Full Prescribing Information. U.S. Food and Drug Administration (Drugs@FDA), NDA 210557, 2019. https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/210557s000lbl.pdf
2. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstetrics and Gynecology, 2019. https://pubmed.ncbi.nlm.nih.gov/31599840/
3. Long-Term Safety and Efficacy of Bremelanotide for Hypoactive Sexual Desire Disorder. Obstetrics and Gynecology, 2019. https://pubmed.ncbi.nlm.nih.gov/31599847/
4. VYLEESI (bremelanotide injection) current structured product labeling (Highlights). U.S. Food and Drug Administration / National Library of Medicine SPL, 2026. https://www.accessdata.fda.gov/spl/data/3dca0cf9-a278-4c25-af93-d65f1f523504/3dca0cf9-a278-4c25-af93-d65f1f523504.xml

Medical disclaimer: This article is for educational purposes only and is not medical advice. Treatment decisions are made by a licensed clinician based on your individual health history and clinical review. New Blue Health is a technology and administrative services platform, not a medical provider.