- Classification: Synthetic Peptide; Analog of Alpha-Melanocyte Stimulating Hormone ($\alpha$-MSH).
- Status: Research Chemical (Not FDA-approved for human use).
- Mechanism: Non-selective agonist of melanocortin receptors (MC1, MC3, MC4, MC5).
- General Dosing Range: * Loading Phase: 250 mcg to 500 mcg daily (titrating up to 1 mg if tolerated).
- Maintenance: 500 mcg to 1 mg, 1–2 times per week.
- Dosing Strategy: “Start Low, Go Slow.” Gradual titration minimizes initial side effects like nausea.
- Saturation/Peak: * Acute Peak: 2–6 hours post-injection for libido/nausea.
- Systemic Saturation: 1–3 weeks for noticeable pigment changes.
- Half-Life: Approximately 1 to 2 hours (though biological effects on skin last much longer).
- Detection: Generally not tested on standard drug panels; requires specialized LC-MS/MS testing.
- Pathways: * Genomic: Stimulates gene expression for eumelanin (darker pigment) production.
- Non-Genomic: Direct activation of G-protein coupled receptors (GPCRs) for immediate effects (libido/appetite).
- Key Benefits:
- Enhanced skin pigmentation (tanning) with minimal UV exposure.
- Increased libido and erectile function (via MC4R).
- Appetite suppression and potential fat loss.
- Side Effects: Nausea (most common), facial flushing, spontaneous erections, darkening of existing moles/freckles, yawning, and lethargy.
- Synergies: * Low-Dose UV: Minimal sunlight (10-15 mins) “activates” the tan.
- PT-141: Often compared or stacked for sexual health (though redundant).
- Avoid Taking With: * PDE5 Inhibitors (Viagra/Cialis): May lead to overly prolonged erections (priapism).
- Appetite Stimulants: MT2 will counteract them.
- Duration of Use: Cycles typically last 4–8 weeks for loading, followed by indefinite maintenance as needed.
General Overview & Clinical Notes
Melanotan 2 is a potent synthetic peptide originally developed at the University of Arizona as a potential defense against skin cancer. By mimicking the body’s natural $\alpha$-MSH, it stimulates the production of melanin without requiring the high levels of DNA-damaging UV radiation usually necessary for a tan. Unlike its “cousin” Melanotan 1 (Afamelanotide), MT2 is a circularized molecule, allowing it to cross the blood-brain barrier. This is why MT2 affects not just skin color (MC1R), but also appetite and sexual arousal (MC3/4R).
In a practical setting, the “loading phase” is the most critical period. Users often report significant nausea if they start with a high dose (e.g., 1 mg). Clinical observation suggests that injecting just before bed can help the user “sleep through” the peak of the nausea. It is also important to note that while MT2 increases melanin, it does not provide a 100% “get out of jail free” card for sunbeds; the skin can still burn, and the risk of hyperpigmentation (uneven dark spots) increases if the dose is too high too quickly.
From a safety perspective, the darkening of moles is the most frequently reported concern. While research has not definitively linked MT2 to melanoma, the darkening can make it difficult for dermatologists to perform accurate skin checks. Users are generally advised to have a baseline skin map performed by a professional before starting a cycle. As with all peptides, quality and purity are paramount, as contaminants in unverified products can lead to systemic inflammation or immune reactions.