Melanotan 2 Dosage Calculator

You have a 10 mg vial of white powder, a vial of bacteriostatic water, and a syringe marked in units rather than milligrams. The calculator bridges those three objects with one number: concentration. Vial milligrams divided by water millilitres gives mg/mL, and your dose divided by that concentration gives the volume to draw.

Think of cordial in a jug. One bottle of cordial in two litres of water is weaker than the same bottle in one litre, so you pour more of the weak mix to get the same amount of cordial. Melanotan 2 works the same way. The dose is always the dose. What changes with the water is how much liquid carries it.

In numbers: a 10 mg vial with 2 mL of water is 5 mg/mL. A 0.5 mg dose is 0.1 mL, which reads as 10 units on a U-100 insulin syringe; 0.25 mg is 5 units and a 0.1 mg test dose is 2 units. With 1 mL of water the vial is 10 mg/mL and every draw halves, which is why the dosage guide prefers 2 mL: a one-unit slip is 0.05 mg instead of 0.1 mg.

The first injection is the one most people remember, because nausea and flushing peak 30 to 90 minutes after it and the intensity tracks the dose. Protocols reported in the community open at 0.25 mg for three evenings, or 0.1 mg for Type I skin, before moving to the full 0.5 mg. The original phase I study at the University of Arizona dosed by body weight, 0.01 to 0.03 mg/kg, and recorded nausea, stretching and yawning as the dominant effects at the higher end (Dorr et al., Life Sci 1996, PMID 8637402).

The calculator pre-fills that test dose and flags any dose above the reported ceiling for your skin type. A 1 mg first injection at 5 mg/mL is 20 units, four times the usual start, and that is the kind of multiple seen in the published overdose reports.

Loading builds melanin. Maintenance keeps it. The daily loading dose is 0.5 mg across skin types once the first three days are tolerated, and what the Fitzpatrick type controls is duration. Type I skin carries MC1R variants that respond weakly to melanocortin signalling, so it loads for three to four weeks. Type IV olive skin reaches its colour in seven to ten days. Types V and VI deepen in under a week.

The cumulative loading figure in the result panel adds three ramp days at the test dose to the remaining days at 0.5 mg, using the midpoint of the reported range. For Type II that is 0.75 mg plus 7.5 mg, about 8 mg from a single 10 mg vial. Reconstituted Melanotan 2 holds for 30 to 40 days in the fridge, so one vial covers loading for every skin type.

Maintenance drops to 0.5 mg at a frequency set by skin type, from twice weekly for Type I down to once every two or three weeks for Types V and VI. Without it the tan fades over four to eight weeks as melanocytes turn over. Some reports use a single 1 mg weekly injection instead of two 0.5 mg doses; the calculator treats that as above the reported per-injection amount and says so, because the side effects on injection day scale with the bolus. The Melanotan 1 vs 2 comparison covers why the MC1R-selective analog follows a different schedule.

Evening injection is the consistent recommendation across community protocols, for a mechanical reason: the nausea window lands while you are asleep. Melanotan 2 has a half-life of roughly 33 minutes, so the tanning signal comes from daily repetition rather than from the peptide lingering.

UV does not change the dose. It changes how fast the colour appears. The dosage guide reports 10 to 15 minutes of sun during loading as enough to accelerate visible tanning, since the peptide drives melanin production while UV triggers its distribution into the visible skin layers. Longer sessions add burn risk, not pigment. The Melanotan II profile covers the receptor mechanism behind this split.