Melanotan 2
Melanotan II
Melanotan II (MT-II) is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (α-MSH) originally developed at the University of Arizona for photoprotection and tanning without UV exposure. It is primarily used for inducing skin tanning, treating erectile dysfunction, and has been investigated for its effects on libido and appetite suppression. It is not approved by the FDA or EMA for any medical use and is sold exclusively as a research chemical.
Mechanism of Action
MT-II acts as a non-selective agonist at melanocortin receptors (MC1R, MC3R, MC4R, and MC5R). Activation of MC1R on melanocytes stimulates eumelanin production, causing skin darkening, while MC4R activation in the hypothalamus mediates pro-erectile effects, libido enhancement, and appetite suppression. Unlike the endogenous α-MSH, MT-II's cyclic structure confers greater metabolic stability and potency, resulting in prolonged receptor activation.
Evidence by Health Goal(16 goals)
Dosing Protocols
Evening, approximately 1–2 hours before sleep to mitigate nausea
Cycle: Loading phase of 1–4 weeks until desired tan is achieved, then maintenance as needed
Reconstitute lyophilized powder with bacteriostatic water. Start at the lowest dose (0.1–0.25mg) to assess tolerance for nausea and flushing. Subcutaneous injection into abdominal fat is most common. UV exposure or tanning bed use enhances tanning response but is not required.
Evening, approximately 1–2 hours before sleep
Cycle: Same loading/maintenance pattern as injection; loading phase typically longer due to lower bioavailability
Nasal administration offers lower and more variable bioavailability compared to subcutaneous injection. Nasal sprays are prepared from reconstituted peptide. Onset of effects is slower and dose consistency is less reliable. Some users prefer this route to avoid injections, though efficacy is reduced.
Safety & Side Effects
MT-II has no regulatory approval and its long-term safety in humans has not been formally studied in controlled clinical trials; the most serious concern is its potential to stimulate growth or transformation of melanocytic nevi, raising unresolved questions about melanoma risk. Users should undergo regular dermatological screening, and individuals with a personal or family history of melanoma or dysplastic nevi should avoid use entirely. It is a controlled or restricted substance in several jurisdictions including the UK, Australia, and Canada.
Possible Side Effects
- !Nausea and vomiting, especially within 30–60 minutes of injection at higher doses
- !Facial flushing and sensation of warmth shortly after administration
- !Spontaneous and prolonged penile erections (priapism risk at higher doses)
- !Fatigue and yawning within 1–2 hours of dosing
- !Darkening and proliferation of existing moles and nevi (potential malignancy concern)
- !Appetite suppression and reduced food intake
- !Increased libido and unsolicited sexual arousal
- !Localized injection site reactions including redness and irritation
Interactions
- -Can cause additive hypotension when combined with PDE5 inhibitors (sildenafil, tadalafil) — combination may result in severe blood pressure drop
- -May potentiate erectile response of other pro-erectile agents, increasing priapism risk
- -Additive appetite suppression with GLP-1 receptor agonists (semaglutide, liraglutide) may exacerbate nausea and weight loss
- -Caution with antihypertensive medications — MC4R-mediated cardiovascular effects may lower blood pressure unpredictably
- -Potential interaction with immunosuppressants in patients with organ transplants due to effects on melanocyte activity and immune-modulating melanocortin pathways
Cost & Where to Buy
Research-grade lyophilized MT-II is typically sold in 10mg vials at $20–$50 per vial from peptide research vendors. Monthly cost depends heavily on dosing frequency and phase (loading vs. maintenance). Bacteriostatic water and insulin syringes add minor additional cost. Quality and purity vary significantly between vendors with no regulatory oversight.
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