Bremelanotide side effects and risks

Reported side effects

• Nausea: 40.0% vs 1.3% placebo; 8% stopped because of nausea., moderate (source)
• Flushing: 20.3% vs 0.3% placebo., mild (source)
• Injection-site reactions: 13.2% vs 8.4% placebo., mild (source)
• Headache: 11.3% vs 1.9% placebo., moderate (source)
• Vomiting: 4.8% vs 0.2% placebo., moderate (source)
• Fatigue: 3.2% vs 0.5% placebo., moderate (source)
• Dizziness: 2.2% vs 0.5% placebo., moderate (source)
• Temporary blood pressure rise: Maximum mean rises 6/3 mmHg; heart rate fell up to 5 beats/min. Usually resolves within 12 hours., serious (source)
• Persistent dark patches: About 1% vs 0% placebo with up to 8 monthly doses. Daily dosing caused much higher rates., moderate (source)
• Acute liver inflammation: One extension case after 10 doses in a year; causality uncertain., serious (source)

Stop and get help if

• Chest pain, fainting, severe headache or new weakness.: Stop dosing and seek emergency care.
• Severe or persistent vomiting, or inability to keep fluids down.: Stop dosing and get prompt medical assessment.
• Yellow eyes, dark urine or severe upper abdominal pain.: Seek urgent assessment for liver injury.
• A new or changing mole, uneven color, bleeding or a fast-growing spot.: Pause use and arrange prompt skin assessment.
• An erection lasting 3–4 hours after off-label use in a man.: Seek emergency care; do not repeat the dose.

Who should avoid it

• uncontrolledBloodPressure: Formal Vyleesi contraindication; each dose can raise blood pressure.
• heartCondition: Known cardiovascular disease is a formal contraindication.
• pregnant: Animal studies found fetal harm. Stop if pregnancy is suspected.
• tryingToConceive: Use effective contraception; pregnancy exposure is insufficiently studied.
• breastfeeding: Infant safety is unknown. A completed milk-PK registration has no posted results.
• under18: Pediatric safety and effectiveness have not been established.
• melanomaOrAtypicalMoles: Precaution for melanocortins. This is not a formal Vyleesi label contraindication.
• kidneyDisease: Severe impairment increases exposure and may worsen nausea or vomiting.
• liverDisease: Severe impairment was not studied; moderate impairment increases exposure.
• other: Higher cardiovascular risk needs review even without diagnosed cardiovascular disease.

Interactions

• Oral naltrexone: Can greatly reduce naltrexone exposure. Avoid with oral products used for alcohol or opioid addiction.
• Oral drugs needing reliable absorption: Slower stomach emptying can reduce or delay drug uptake. The label advises avoiding use with threshold-dependent oral drugs.
• Other melanocortin agonists: Duplicate receptor activity may add pigment or systemic effects. This combination has no established dosing safety.
• Sildenafil or tadalafil: A small nasal sildenafil study exists. It does not establish safety of injected PT-141 with tadalafil.
• Ondansetron pretreatment: 8 mg orally 30 minutes before Vyleesi did not prevent nausea and is not recommended for that purpose.
• Alcohol: A small nasal study found no major interaction at 0.6 g/kg. This does not cover heavy drinking or all health conditions.

Product quality risks

• Forensic LC-HRMS identified bremelanotide in seized black-market samples; this did not establish safe strength, sterility or stability.
• Compounded medicines are not FDA-approved. Contamination and incorrect strength can cause serious harm.