PT-141: Side Effects & Safety
Part of the PT-141 Complete Guide
Research Peptides
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Overall Safety Profile
PT-141 has been evaluated in Phase 3 clinical trials with over 1,200 participants. Nausea is the most significant tolerability issue, affecting 40% of users and leading some to discontinue treatment. The FDA limited dosing frequency to no more than 8 times per month to manage cumulative hyperpigmentation risk.
Reported Side Effects
- Nausea (40%): The most common and dose-limiting side effect — significantly limits tolerability
- Flushing (20%): Facial and body flushing related to melanocortin activation
- Injection site reactions (13%)
- Headache (11%)
- Hyperpigmentation: Skin darkening with repeated use, particularly in darker-skinned individuals and pigmentation-prone areas
- Blood pressure increase: Transient BP elevations (mean 2–3 mmHg systolic)
Important Safety Considerations
The 40% nausea rate is substantially higher than most peptides. Blood pressure effects contraindicate use in uncontrolled hypertension and cardiovascular disease. Hyperpigmentation risk limits long-term frequent use. The FDA-approved dosing limit (8×/month) reflects these cumulative concerns.
Contraindications
- Uncontrolled hypertension or cardiovascular disease
- Known hypersensitivity to bremelanotide
- Concurrent use of naltrexone (pharmacological interaction)
- Pregnancy and breastfeeding
See the PT-141 overview for complete information.