Melanotan II

Potent α-MSH analog - deep tanning with less UV, and a strong centrally-mediated libido effect.

Human trialsResearch chemicalInjectableMelanocortin

Key facts

Common routesSubcutaneous (standard), intranasal

Half-life~1 hour

Typical range100-1000 mcg/dose

Résumé

Melanotan II is a synthetic analog of α-melanocyte-stimulating hormone (α-MSH). It activates MC1R on skin melanocytes (tanning) and MC3R/MC4R in the CNS (libido and appetite suppression). In practice: a deeper tan with substantially less UV exposure, plus a reliable centrally-driven libido effect.

Important: Melanotan II is not the same as Melanotan I (afamelanotide / Scenesse) - that one is FDA-approved for EPP, MT-II is not. Side-effect profile is “dirty” (nausea, flush, mole darkening, priapism risk), but most users get it to a manageable level with a ramp-up protocol.

Notes sur le mécanisme

MC1R agonism (melanogenesis)

Binds melanocortin-1 receptors on skin melanocytes and drives tyrosinase activity and eumelanin synthesis. Result: deeper pigmentation for a much smaller UV dose - but UV is still required to “develop“ the pigment and make the tan look natural.

MC3R/MC4R agonism (CNS)

Activates hypothalamic melanocortin receptors involved in sexual arousal and energy homeostasis. Explains both the libido effect (Wessells 2000 showed >80% response in psychogenic ED) and the appetite suppression.

Schémas de dosage

Loading + maintenance (tanning)

Day 1-3: 100 mcg. Day 4-6: 250 mcg. Day 7+: 500 mcg daily until desired shade. UV 20-30 min, 2-3× per week is required, otherwise no color develops. Maintenance: 500 mcg - 1 mg once per week. Pigmentation lasts several months.

On-demand protocol (libido / ED)

250-500 mcg subcutaneous, 4-6 hours before activity. Onset is 2-4 hours and effect lasts 12-24 hours. Start at 50-100 mcg to gauge sensitivity - don't combine a full dose with PDE5 inhibitors or you're courting priapism.

Aperçu des données

Evidence is surprisingly solid for a research chemical: Wessells et al. (1998, 2000) ran small RCTs with robust effect in psychogenic ED; Dorr et al. (1996) demonstrated the tanning signal in a pilot. On top of that, 15+ years of broad community experience with a visually measurable endpoint (skin color). The gap: no long-term safety data on chronic melanocyte stimulation.

ED trials (Wessells 1998/2000)

Small RCTs with clear efficacy in psychogenic ED - but with high nausea rates at the doses used at the time.

Tanning evidence

Dorr 1996 + decades of global community use. For Fitzpatrick skin types I-IV the response is close to 100%.

Considérations de sécurité

Nausea and flush are nearly guaranteed on the first doses but drop off sharply with a ramp-up schedule and evening dosing before sleep. An antihistamine (e.g. cetirizine) 1 hour before the shot helps. The dermatological effects (darker moles, possible new nevi, lip/gum hyperpigmentation) are permanent - mole mapping before starting is the controllable variable.

Key cautions

Les grains de beauté et taches de rousseur existants vont foncer - cartographiez vos grains de beauté avant de commencer et arrêtez en cas de changement de forme ou de texture
Le priapisme (érection >4 heures) est une urgence médicale ; commencez à 50-100 mcg pour évaluer la réponse et évitez la combinaison avec des inhibiteurs de PDE5 à pleine dose
L'exposition aux UV reste nécessaire pour oxyder le pigment - sans UV, le bronzage peut paraître gris plutôt que brun