COMMON INITIAL DOSING REGIMENS

• A common starting dose is 250–500 mcg subcutaneously once daily or every other day, titrated based on response and side effects. Initial loading periods typically last 1–2 weeks, followed by lower maintenance doses administered once or twice weekly.

MECHANISM OF ACTION

• Melanotan II is a synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH), which binds to melanocortin receptors, particularly MC-1R and MC-4R. Activation of MC-1R in the skin stimulates melanin production in melanocytes, leading to increased pigmentation (tanning), even with minimal sun exposure.

• MC-4R stimulation in the hypothalamus also enhances libido and erectile function via central nervous system pathways. The drug may also influence appetite and energy homeostasis, although this is not its primary therapeutic goal.

COMMON SIDE EFFECTS

• General: Nausea, facial flushing, and appetite suppression, particularly during early dosing.

• Dermatologic: Increased skin pigmentation, freckles, and new or darkened moles.

• Sexual: Spontaneous or prolonged erections (priapism), increased libido.

• Injection Site: Redness, bruising, or irritation.

• Rare: Headache, fatigue, or anxiety. In very rare cases, pigment changes in preexisting nevi may raise concern for atypical mole development.

CONTRAINDICATIONS

• Absolute: Known hypersensitivity to Melanotan II or any of its excipients. History of melanoma or atypical mole syndrome.

• Relative: Use with caution in individuals with a strong family history of skin cancer, significant sun exposure, or those with numerous pigmented lesions. Caution in patients with cardiovascular disease due to transient blood pressure and heart rate effects.

COMPARISON WITH OTHER AGENTS

• Tadalafil/Sildenafil: These PDE5 inhibitors act directly on vascular smooth muscle to induce erections, while Melanotan II works centrally and may be more effective in individuals with psychogenic or neurogenic erectile dysfunction.

• Sun exposure or tanning beds: Melanotan II can increase pigmentation without requiring harmful UV exposure, although sun exposure is still often used to “activate” the tanning effect.

• Bremelanotide (PT-141): A closely related melanocortin receptor agonist FDA-approved for hypoactive sexual desire disorder in women. Melanotan II has a broader range of effects and is typically used off-label.

EXPERIMENTAL TREATMENT DISCLAIMER:

• Melanotan II is not approved by the FDA for any medical or cosmetic use. Its use is considered experimental. While it has demonstrated efficacy for tanning and sexual arousal in early studies, it has not undergone comprehensive safety evaluations. Potential long-term risks, particularly regarding pigmentation changes and skin cancer risk, remain unknown. The patient acknowledges the investigational nature of this therapy and agrees to proceed at their own risk.

MORE INFORMATION

• FDA Safety Data Sheet not available (experimental peptide).