Melanotan 2 — Research, Dosing & Price Guide

Melanotan-2 (MT-2) is a synthetic cyclic peptide analog of alpha-melanocyte-stimulating hormone (α-MSH) that produces skin tanning, enhances sexual arousal, and suppresses appetite through broad melanocortin receptor activation. It is one of the most widely used research peptides globally, known for its potent multi-receptor activity across MC1R through MC5R. Unlike Melanotan-1, its non-selective binding profile produces a diverse range of physiological effects beyond melanogenesis.

Melanotan-2 is a cyclic heptapeptide (Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-NH₂) designed with a lactam bridge between positions 4 and 10 that confers exceptional metabolic stability and receptor binding potency compared to linear α-MSH. Its mechanism is multifaceted due to non-selective activation of melanocortin receptors MC1R through MC5R, each mediating distinct physiological responses. At MC1R on melanocytes, MT-2 triggers the same cAMP/PKA/MITF cascade as Melanotan-1, driving eumelanin synthesis and producing progressive skin darkening. This occurs even without UV exposure, though concurrent moderate UV exposure significantly accelerates and deepens the tanning response by providing the oxidative stress signals that synergize with melanocortin signaling. At MC4R in the hypothalamus, MT-2 produces two clinically significant effects. First, it activates pro-opiomelanocortin (POMC) neurons in the arcuate nucleus, reducing appetite and food intake through the same anorexigenic pathway targeted by setmelanotide (an FDA-approved MC4R agonist for genetic obesity). Second, MC4R activation in the paraventricular nucleus triggers descending autonomic pathways to the sacral spinal cord, promoting penile erection in males and genital arousal in females. This erectogenic effect is centrally mediated — it originates in the brain rather than acting on peripheral vasculature like PDE5 inhibitors, making it effective even in cases of psychogenic erectile dysfunction. At MC3R, MT-2 modulates energy homeostasis and fat partitioning, contributing to favorable body composition changes observed during use. MC5R activation affects exocrine gland function, potentially altering sebum production. The peptide also demonstrates anxiolytic properties in preclinical models, likely through melanocortin modulation of limbic circuits. The cyclic structure gives MT-2 a half-life of approximately 1–2 hours after subcutaneous injection, but its biological effects (particularly melanogenesis) persist far longer due to downstream gene expression changes that continue for days after receptor activation. This pharmacokinetic-pharmacodynamic disconnect allows for infrequent dosing during maintenance phases.

• Dorr et al. (1996) in the Archives of Dermatology demonstrated that MT-2 significantly increased melanin density and tanning in fair-skinned men after subcutaneous dosing, providing the first human proof-of-concept
• A landmark study in the International Journal of Impotence Research (1998) showed that MT-2 induced erections in 8 of 10 men with erectile dysfunction, with effects occurring 1–5 hours post-injection
• Wessells et al. (2000) published in the Journal of Urology confirming centrally-mediated erectogenic effects independent of visual sexual stimulation, distinguishing MT-2 from PDE5 inhibitors
• Research published in Peptides (2005) demonstrated MT-2 increased sexual desire and genital arousal in premenopausal women with female sexual arousal disorder
• Preclinical studies show MT-2 reduces food intake by 25–40% in rodent models through MC4R-mediated anorexigenic signaling (Pharmacology, Biochemistry and Behavior, 2004)
• A 2009 study in the British Journal of Dermatology confirmed eumelanin (not pheomelanin) upregulation, indicating genuine photoprotection rather than cosmetic-only darkening
• Van der Klaauw et al. (2016) demonstrated MC4R's role in human energy homeostasis, supporting the mechanism by which MT-2 suppresses appetite
• Case series in the Journal of the European Academy of Dermatology (2013) documented consistent tanning responses across Fitzpatrick skin types I–III

• Loading phase: 0.25 mg subcutaneous injection daily for the first 2–3 days to assess tolerance, then increase to 0.5–1.0 mg daily
• Standard loading protocol: 0.5 mg daily for 14–21 days until desired tan is achieved
• Maintenance: 0.5–1.0 mg twice weekly to sustain pigmentation
• For sexual enhancement (acute use): 0.5–1.0 mg administered 2–4 hours before anticipated activity
• Best injected in the evening — nausea is most common in the first hour and sleep helps bypass discomfort
• Combine with 10–20 minutes of UV exposure 4–6 hours post-injection during loading phase for optimal tanning
• Some users pre-treat with an antihistamine (to reduce flushing) or antiemetic (to reduce nausea) for the first several doses
• Maximum suggested research dose: 1.0 mg per day; exceeding this does not accelerate results and increases side effects
• Typical full cycle: 3–4 weeks loading, then indefinite maintenance at reduced frequency
• Allow at least 4–6 weeks between loading cycles if taking breaks

Known Side Effects

• Nausea — the most frequently reported side effect, occurring in up to 80% of users during the first 3–5 doses; typically dose-dependent and diminishes with continued use
• Facial flushing — transient warmth and redness lasting 30–90 minutes post-injection, caused by peripheral vasodilation via melanocortin receptors on vascular endothelium
• Spontaneous or prolonged erections — can occur 1–5 hours post-injection; priapism is rare but has been reported and constitutes a medical emergency
• Appetite suppression — significant reduction in hunger lasting 12–24 hours post-dose; can lead to unintended weight loss during loading phases
• Darkening of existing moles, freckles, and nevi — requires dermatological monitoring; new nevi formation has been reported in case studies
• Fatigue and yawning — commonly reported 30–60 minutes post-injection, likely mediated by central melanocortin effects
• Injection site soreness — mild localized pain or redness that resolves within hours
• Mood changes — some users report mild euphoria or increased sociability, while others note irritability during initial loading

Safety Profile

Melanotan-2 is an unregulated research peptide with no FDA or EMA approval, and its safety profile is derived primarily from small clinical studies and extensive anecdotal community reporting rather than large-scale trials. The most significant safety concern is dermatological: MT-2 stimulates all melanocytes, including those in preexisting nevi, and there are case reports of atypical mole changes and melanoma-in-situ diagnosed during MT-2 use, though causation has not been established. A baseline dermatological exam and regular skin checks every 6 months are strongly recommended. Individuals with a personal or family history of melanoma, dysplastic nevus syndrome, or numerous atypical moles should avoid MT-2 entirely. The erectogenic effects carry a small but real risk of priapism — persistent erection lasting more than 4 hours requires emergency medical intervention. Cardiovascular effects are generally mild (transient blood pressure elevation, flushing), but those with uncontrolled hypertension should exercise caution. Because MT-2 is predominantly sourced from unregulated suppliers, purity and sterility are significant concerns — sourcing from third-party tested suppliers is essential. There are no known dangerous drug interactions, though combining with PDE5 inhibitors (sildenafil, tadalafil) may increase priapism risk.

Days 1–3: Nausea and facial flushing are common within 30–60 minutes of injection. Some users experience yawning, fatigue, or spontaneous erections. No visible tanning yet. Start at 0.25 mg to gauge response. Days 4–7: Nausea typically subsides by day 4–5 as the body acclimates. Existing freckles and moles begin to darken noticeably. A subtle warmth to skin tone may appear, especially with some UV exposure. Appetite suppression becomes apparent. Weeks 2–3: Visible tan develops and deepens progressively. The color tends toward a natural brown-olive tone rather than orange. Sexual effects (increased libido, stronger erections) are consistently reported. Appetite remains suppressed; some users note 2–4 lbs of weight loss. Weeks 4+: Tan is fully established and can be maintained with twice-weekly dosing. Sexual enhancement effects persist at maintenance doses. After cessation, the tan fades over 4–8 weeks depending on sun exposure and skin turnover rate. Mole darkening gradually reverses but should be monitored.

Prices sourced from peptides.gg marketplace. Prices may vary.