Melanotan II Dosage Chart.

The number people use is 250 mcg (5 units on a U-100 syringe from a 10 mg vial mixed with 2 mL of bacteriostatic water), injected once nightly to load, then once or twice a week to hold the colour. Be clear about what that figure is: Melanotan II has never been approved anywhere, so there is no label and no regulator-reviewed dose, and 250 mcg is the range community and vendor protocols converged on rather than a trial result. The three human studies that exist used weight-based dosing of 0.01 to 0.025 mg/kg subcutaneously, roughly 800 to 2,000 mcg for an 80 kg adult. Convention settled well below that, most likely because the trial doses made people nauseated.

On a U-100 syringe, 100 units equals 1 mL. Mix a 10 mg vial with 2 mL of bacteriostatic water and you get 5,000 mcg/mL, so one unit is 50 mcg. That makes 100 mcg equal 2 units, 250 mcg equal 5 units, and 500 mcg equal 10 units. If you mix the same vial with 1 mL instead, one unit becomes 100 mcg and a 250 mcg dose lands on 2.5 units, which sits between marks and is harder to draw accurately. When in doubt, use more water rather than squinting at half-marks, and use the narrowest barrel you own, because a 0.3 mL syringe spreads 5 units over three times the length a 1 mL syringe does.

Nobody separated the two properly, so be sceptical of confident answers in either direction. The phase I subjects did develop measurable pigmentation, but their UV exposure was not controlled or reported, so that study cannot tell you whether Melanotan II tans you on its own. What is documented is that real-world use tends to be paired with sunbeds, and that pairing is where much of the recorded harm sits. Using this compound as a reason to spend more time under UV is the worst version of the decision.

No one has measured that, so do not assume any protection. There is no published SPF equivalent for Melanotan II induced pigmentation, and the recent dermatology literature reviewing tanning products does not claim one. Treat your sun protection as completely unchanged: same sunscreen, same shade, same clothing. Assuming a peptide tan is protective and then extending your exposure on the strength of that assumption is precisely how this compound causes the harm it is most associated with.

Because Melanotan II is not a tanning drug that happens to have side effects. It is a non-selective melanocortin receptor agonist, and MC1R is only one of the receptors it activates. The nausea, flushing, appetite suppression, yawning and stretching, and spontaneous erections all come from MC3 and MC4 activation, and it crosses the blood-brain barrier readily. There is no dose that gives you the pigment effect without the rest, which is the fundamental design problem with this molecule. Dosing in the evening and starting at 2 units is the only real mitigation.

It has never been published in humans. That is worth stating flatly, because half-life figures for Melanotan II circulate widely on vendor pages with nothing behind them. The only pharmacokinetic study in the literature was done in rats given a 0.3 mg/kg intravenous dose, and that paper was a comparison of two assay methods that does not even report the half-life values in its abstract. Nothing about rat IV kinetics transfers usefully to a human subcutaneous dose. What is documented in humans is duration of observed effect, which ran one to five hours in the phase I study. That is also why evening dosing works, and why nobody doses this twice a day.

No, and this conflation is often used to make Melanotan II sound safer than the evidence supports. Afamelanotide, sold as Scenesse, is a different molecule: an MC1R agonist given as a 16 mg bioresorbable implant inserted by a trained healthcare professional every two months, FDA approved in 2019 for one narrow indication: increasing pain-free light exposure in adults with erythropoietic protoporphyria. It is not approved for cosmetic tanning. Melanotan II is a different, non-selective cyclic peptide that has never been approved for anything, in any country, at any dose. The existence of an approved cousin tells you nothing about the safety of an unapproved one.

Probably not, and this is measured rather than speculated. Researchers used LC-UV-MS/MS to analyse melanotan II vials bought from three online shops, all labelled 10 mg. The actual content ranged from 4.32 to 8.84 mg, so the worst vial held under half of what it claimed. Vials from two of the three shops also contained unidentified impurities at 4.1 to 5.9%. The practical consequence is that your reconstitution maths is far more precise than your starting material, and two vials from different batches can deliver meaningfully different doses at the same number of units. Re-test with a small dose whenever you open a new vial rather than assuming continuity.