Side Effects
Common Side Effects:
- Nausea (most frequent, especially with initial doses)
- Facial flushing and warmth
- Fatigue or drowsiness
- Appetite suppression
- Spontaneous or prolonged erections in men
Less Common Side Effects:
- Darkening of existing moles and freckles
- Development of new nevi (moles)
- Injection site reactions (redness, pain, swelling)
- Headache
- Dizziness
Concerns Requiring Attention:
Mole darkening raises melanoma concerns due to MT-II's direct stimulation of melanocytes. Multiple published case reports in peer-reviewed journals, including the British Journal of Dermatology, have documented melanomas arising during MT-II use. Both the UK's MHRA and Australia's TGA have issued formal safety warnings specifically citing melanoma risk. While definitive population-level causality has not been established through large-scale epidemiological studies, the evidence goes well beyond theoretical concern. Those with numerous atypical moles, a personal or family history of melanoma, or very fair skin (Fitzpatrick type I) are at particular risk. Regular dermatological monitoring is advisable for anyone using MT-II.
The Wessells 1998 study showed dose-dependent erections lasting 1–5 hours in subjects receiving MT-II, and priapism (erection lasting more than 4 hours) is a recognized risk. Priapism constitutes a urological emergency requiring immediate attention, as delayed treatment can result in permanent erectile dysfunction.
Products sourced from unregulated channels may vary significantly in purity, potency, and sterility, introducing additional safety risks independent of the compound itself.