Skip to content
The Peptide Effect
preclinicalTanning & Sexual Health

Melanotan II

Also known as: MT-2, MT-II, Melanotan 2

Melanotan II is a synthetic cyclic peptide analog of alpha-melanocyte-stimulating hormone (α-MSH) that acts as a non-selective melanocortin receptor agonist. Originally developed at the University of Arizona for skin cancer prevention via UV-free tanning, it was never approved by any regulatory agency. It remains widely used as an unregulated research chemical for tanning and sexual enhancement despite significant safety concerns, including potential melanoma risk.

Key Facts

Mechanism
Melanotan II is a non-selective agonist of melanocortin receptors MC1R, MC3R, MC4R, and MC5R. MC1R activation in melanocytes stimulates eumelanin production (melanogenesis), resulting in skin darkening without UV exposure. MC4R activation in the hypothalamus triggers sexual arousal pathways and suppresses appetite via pro-opiomelanocortin (POMC) neuron signaling. MC3R activation contributes to energy homeostasis and fat metabolism. This broad receptor profile produces its multi-system effects but also underlies its significant side effect profile.
Research Status
preclinical
Half-Life
~30–60 minutes
Molecular Formula
C₅₀H₆₉N₁₅O₉
Primary Use
Tanning & Sexual Health

Benefits

  • Induces skin tanning via melanin production without requiring UV exposure — visible darkening typically within 1–2 weeks of loadingmoderate
  • Appetite suppression — significant reduction in food intake observed in clinical studies via MC4R activationmoderate
  • Enhanced sexual arousal and erectile function in both men and women via central melanocortin pathwaysmoderate
  • May provide partial photoprotection — increased melanin can reduce UV-induced DNA damage in fair-skinned individualspreliminary
  • Fat loss potential — MC3R/MC4R activation influences energy expenditure and lipid metabolism in animal modelspreliminary

Dosage Protocols

RouteDosage RangeFrequencyNotes
Subcutaneous injection (loading phase)0.25–0.5 mg dailyDaily for 1–2 weeksStart at 0.25 mg to assess tolerance. Nausea is dose-dependent — lower starting doses reduce side effects. Loading continues until desired skin tone is reached.
Subcutaneous injection (maintenance phase)0.5 mg1–2× per weekMaintenance dose maintains skin tone once desired level is achieved. Some users require only bi-weekly injections.
Nasal spray (less common)0.5–1.0 mg1–2× daily during loading, then as neededLower bioavailability than subcutaneous injection. Less reliable absorption and effects.

Medical disclaimer

Dosage information is provided for educational reference only. Always follow your prescriber's instructions and consult a qualified healthcare provider before starting any peptide protocol.

Side Effects

  • Nausea — very common during loading phase, reported by majority of users; typically dose-dependent and diminishes over timecommon
  • Facial flushing and warmth — occurs within minutes of injection, usually lasts 30–60 minutescommon
  • Appetite suppression — can be significant enough to interfere with nutrition, particularly during loadingcommon
  • Spontaneous erections in men — frequently reported, can be persistent and socially inconvenientcommon
  • Darkening of existing moles and appearance of new moles — raises serious concern for masking or promoting melanoma; dermatological monitoring strongly recommendedserious
  • Potential melanoma risk — MC1R activation may promote proliferation of atypical melanocytes; multiple case reports of melanoma in Melanotan II users, though causation is not establishedserious

Frequently Asked Questions

Does Melanotan II cause skin cancer?
The relationship between Melanotan II and melanoma is not fully established, but there are serious concerns. Several case reports document melanoma diagnosis in Melanotan II users, and MC1R stimulation can theoretically promote growth of existing atypical melanocytes. The darkening and proliferation of moles makes self-monitoring more difficult. Dermatologists strongly advise against its use, especially for individuals with many moles, a family history of melanoma, or fair skin. Anyone using MT-2 should have regular full-body skin checks by a dermatologist.
Is Melanotan II legal?
Melanotan II is not approved for human use by the FDA, EMA, TGA, or any major regulatory body. It is classified as a research chemical. In some countries (Australia, UK), it is explicitly banned for sale for human use. In the US, it exists in a gray area — it can be sold as a research chemical but not marketed for human consumption. Purchasing and possessing it is generally not illegal, but selling it as a tanning product is.
Can you tan without UV exposure using Melanotan II?
Melanotan II does stimulate melanin production without UV exposure, and some skin darkening occurs even without sun exposure. However, the tanning effect is significantly enhanced when combined with moderate UV exposure (sun or tanning bed). Most users combine MT-2 with brief UV sessions for optimal results. Pure UV-free tanning produces a more subtle effect.
What is the Melanotan II loading protocol?
The typical loading protocol starts with 0.25 mg subcutaneously once daily, increasing to 0.5 mg daily after assessing tolerance. Loading continues for 1–2 weeks until the desired skin tone is reached. During loading, brief UV exposure (10–20 minutes of sun or a tanning bed session) every 2–3 days enhances results. Once the target tone is achieved, users switch to a maintenance dose of 0.5 mg once or twice weekly. Taking an anti-nausea medication before injection can help manage side effects during loading.
Should I monitor my moles while using Melanotan II?
Absolutely. Mole monitoring is critical for anyone using Melanotan II. Take baseline photographs of all moles before starting, and perform regular self-examinations using the ABCDE criteria (Asymmetry, Border irregularity, Color changes, Diameter increase, Evolution over time). Schedule a professional dermatological exam before starting and at least every 6 months during use. Report any new, changing, or unusual moles immediately. Do not use MT-2 if you have a personal or family history of melanoma or have a high number of atypical moles.

References

  1. 1
    Subcutaneous administration of Melanotan II, a synthetic analog of alpha-melanocyte stimulating hormone, induces tanning in humans(1999)PubMed ↗
  2. 2
    Synthetic melanotropin analogs and their potential role in dermatology(1997)PubMed ↗
  3. 3
    Melanotan II: a review of safety and efficacy concerns surrounding this unlicensed tanning peptide(2015)PubMed ↗
  4. 4
    Melanoma and use of Melanotan-II: case series and review of literature(2018)PubMed ↗

Last updated: 2026-02-14