• Peptide Class: Synthetic analog of α-MSH

• Molecular Formula: C₅₀H₆₉N₁₅O₉

• Molecular Weight: ~1024.18 g/mol

• Structure: Cyclic heptapeptide designed for melanocortin receptor agonism

• Name: Melanotan II (MT-2)

• Type: Synthetic melanocortin receptor agonist

• Function: Stimulates melanin production, enhances skin pigmentation, and promotes sexual arousal

• Use: Commonly used for sunless tanning, UV protection, and libido support

• MC1R → Stimulates melanocytes to produce eumelanin (dark pigment) for skin tanning

• MC4R / MC3R → Increases libido and sexual arousal via the central nervous system

• Photoprotective Action → Increases melanin, which absorbs UV radiation and reduces photodamage

• Promotes natural tan without extensive sunbathing

• Increases UV resistance and reduces risk of sunburn

• May offer long-term photoprotective benefits for fair-skinned individuals

• Enhances libido, sexual pleasure, and arousal

• Improves erectile firmness and reduces performance anxiety

• Effects may be more pronounced than traditional ED medications in some users

• Offers a cosmetic tan without UV damage

• Can complement bodybuilding aesthetics or enhance appearance before events

• Used by actors, models, and athletes for on-demand pigmentation

• Injectable (Subcutaneous) – most common and effective

• Nasal Spray – available in some research forms, with reduced bioavailability

• Oral – not recommended due to degradation in the digestive tract

• Tanning Effects: Demonstrated significant melanin increase and UV protection in clinical studies

• Sexual Arousal: Led to the development of PT-141 (Bremelanotide) after showing unexpected arousal effects in trials

• Photoprotection Studies: Reduced incidence of sunburn and UV-induced skin damage in fair-skinned individuals

• Vitiligo: Early-stage studies suggest potential use in re-pigmentation therapy

Despite promising data, Melanotan II is not FDA-approved due to limited long-term safety studies.

• Facial flushing and warmth

• Nausea, especially during early dosing

• Increased freckles or mole darkening

• Spontaneous erections (in men)

• Headache or fatigue

• Hyperpigmentation in specific areas (e.g., gums, nipples)

• Appetite suppression

• Anxiety or lightheadedness in sensitive users

• Not recommended for those with melanoma risk or pigmentation disorders

• Avoid overuse to prevent excessive tanning or uneven pigmentation

• FDA Status: Not approved; considered an unlicensed research chemical

• Legal Use: Legal for research purposes in many regions; not approved for cosmetic or therapeutic sale

• WADA Status: Banned in competitive sports due to performance-enhancing libido effects