Melanotan II: Side Effects & Safety

Melanotan II is not approved for medical use in any country. Health authorities in the US (FDA), EU (EMA), UK (MHRA), and Australia (TGA) have issued warnings about its use. The safety profile carries significant concerns beyond typical peptide side effects.

• Nausea (very common): The most frequently reported side effect, especially during loading. Severity ranges from mild to severe and is dose-dependent
• Facial flushing: Warmth and redness shortly after injection, typically lasting 15–60 minutes
• Fatigue/lethargy: Drowsiness commonly reported, particularly with evening dosing
• Appetite suppression: Variable — some experience significant decrease in appetite
• Spontaneous erections: In males, MC4R activation can produce erections without sexual stimulation
• Injection site reactions: Standard subcutaneous injection effects

• Mole changes: Melanotan II can darken existing moles and nevi. Health authorities warn this can potentially mask malignant changes in moles, making early melanoma detection more difficult. Any new or changing moles should be evaluated by a dermatologist
• Blood pressure effects: Both increases and decreases in blood pressure have been reported
• Renal effects: Cases of rhabdomyolysis have been associated with melanotan II use (rare)
• Unregulated products: As a non-approved compound, quality control varies significantly between suppliers. Contamination and inaccurate dosing are real risks
• Melanoma risk: While the original research aimed at photoprotection, the concern exists that stimulating melanocyte activity could theoretically promote melanoma in susceptible individuals. This risk is debated in the literature

• History of melanoma or atypical mole syndrome
• Cardiovascular disease or uncontrolled blood pressure
• Pregnancy and breastfeeding
• Liver or kidney disease

Return to the melanotan II overview for general information.