Melanotan II

Melanotan II is a lab made chain of seven of the building blocks that proteins are made from, closed into a ring. Short chains like this are called peptides. It is built from the body's own pigment signal, alpha melanocyte stimulating hormone, the message that tells the cells making skin pigment to make more, and it is sold to be injected under the skin to go darker. The published human record is four trials, 43 men in total, all run by one group at the University of Arizona between 1996 and 2000, and what those trials mostly measured was erections. The tanning part of the record is three men who received five active injections each.

It switches on a family of docking points on cells called melanocortin receptors, the same switches the body's own pigment signal uses. The published description is that it is not selective, meaning it presses several switches in that family rather than the skin colour one alone, and that is why the effects reported in people run past skin colour into spontaneous erections and sexual arousal. The pigment effect itself was seen in the 1996 study: a week after dosing ended, two of the three men showed increased pigment in the face, upper body and buttock.

People buy it to tan, injecting it at home and usually pairing it with a sunbed or the sun. That is what it is sold and talked about for. What the trials actually measured was erections: ten men whose erection problems had no physical cause, ten men who had physical risk factors for them, and a third study in twenty men, all given the same amount under the skin. All four trials enrolled men only, and no trial in women was found.

The mistake is assuming the circulating numbers came out of the research, and here they miss in the unusual direction. The three later trials used 0.025 mg/kg, about 1.75 milligrams for a 70 kilogram adult, and the 1996 first in human study ran 0.01 to 0.03 mg/kg, roughly 0.7 to 2.1 milligrams at that weight, so what circulates is between a seventh and a third of what anybody was given. It sits below the tested amount rather than above it, which is the reverse of nearly everything else in this reference. I could not trace the number to a derivation: one says the figures are extrapolated from the published research range and then names no publication for them, and another concedes in its fine print that no dose approved by the United States Food and Drug Administration exists and that the loading and maintenance models are community derived. The second mistake is what the trials were for. Four trials, 43 men, and what they measured was erections. The tanning claim, which is the reason almost everybody buys it, rests on three men who received five injections each, two of whom went darker.

This is the rare compound in this reference with a real safety file rather than an empty one, and the counting has to be careful, because the published reports may describe the same person twice. In the trials the reported problem was nausea, and not the mild kind: severe nausea followed 4 of 19 injections in the study of ten men with physical risk factors, and ran to about 13 percent in the study of twenty men. Outside the trials, a 39 year old man injected 6 milligrams of internet bought melanotan II under the skin, six times the recommended starting amount, and developed the overstimulated state that adrenaline like substances produce, with a heart rate of 146 beats a minute, a kidney waste measure called creatinine at 2.25 milligrams per decilitre, and a muscle enzyme peaking at 17,773 international units per litre, which is muscle dissolving and passing through the kidneys. He spent three days in intensive care. Priapism, an erection that will not go down and becomes an emergency, is where the counting matters. One report describes a case in which the blood supply was cut off, following an injection under the skin, that failed drainage, flushing and a medicine injected into the penis, and needed an operation to relieve it. Its authors note that priapism after melanotan II had been reported only twice before. A separate report describes a low flow case after an injection under the skin of the abdomen, managed with drainage, flushing and that same injected medicine. Whether that second one is among the two the first was counting cannot be told, so do not read three separate men into this. Two more stand alone: a kidney infarction, meaning tissue dying because its blood supply was blocked, attributed to melanotan II by authors who framed that attribution as possible rather than established, and a brain swelling condition called posterior reversible encephalopathy syndrome, reported by Kaski and colleagues in Annals of Internal Medicine in 2013. Then the pigment cells. A 2017 review of unregulated use of these pigment hormone copies counted four case reports of melanoma, the dangerous skin cancer, emerging from existing moles during or shortly after melanotan use, and named changes in existing moles and newly appearing abnormal moles as the characteristic skin complication. A 20 year old woman with fair skin was diagnosed with melanoma confirmed by biopsy in the buttock area after three to four weeks of injecting herself alongside sunbed use. A 22 year old woman developed a growth in the front of the upper jaw that proved on examination to be malignant melanoma, after using melanotan II nasal spray to tan. And a 2026 report describes five separate melanomas at the earliest stage, still confined to the surface layer, in one patient, inside severely abnormal moles, in someone using melanotan I and II products labelled research use only alongside tanning beds and anabolic hormones. Those may overlap, because it cannot be told which cases the 2017 review's four already counted, so they are not added up here. None of that establishes cause. There is no cohort study, no case control study and no registry analysis, and nearly every reported patient also used a sunbed or chased the sun. Melanotan II holds no approval from the United States Food and Drug Administration for any use and its safety has not been established. It is not named anywhere on the 2026 World Anti-Doping Agency Prohibited List either, and falls under the catch all category S0, for substances with no current approval by any government health authority for human therapeutic use, banned at all times.