Melanotan II

A deliberate decision

This record publishes no dose range. Not because we could not find numbers, since every vendor blog has them, but because every source with numbers is a vendor blog, and printing them would normalise a protocol we have no basis to normalise.

The one dose figure we can state is the toxic one, and it is on this page.

What it is

Melanotan II is a synthetic analogue of alpha-melanocyte-stimulating hormone that activates melanocortin receptors without much selectivity. MC1R activation on melanocytes drives eumelanin production, the tan. MC4R and MC3R activation in the central nervous system produces the appetite suppression and sexual arousal it is also bought for.

Because it hits several receptors at once, you do not get to pick. Pigment changes, nausea, flushing and sympathomimetic cardiovascular effects arrive with everything else.

Note the naming: "the Barbie drug" is Melanotan II. The nickname migrates onto PT-141 in community writing, and it carries the wrong expectations when it does.

The verified toxicity case

Nelson, Bryant and Aks, Clinical Toxicology, 2012, PMID 23121206. A 39-year-old man self-injected 6 mg subcutaneously. He presented with blood pressure 151/85, heart rate rising to 146, dilated pupils and tremor. Creatine kinase went from 1,760 to 17,773 IU/L, which is rhabdomyolysis, with myoglobinuria and red cell casts in the urine. He spent three days in intensive care on fluids and bicarbonate.

That is a verified, primary, emergency-medicine case report of a single self-administered dose putting someone in intensive care.

The pigmentation and melanoma picture, stated honestly

Both halves, because either one alone misleads.

The Skin Cancer Foundation, in a press statement dated 7 July 2026, states verbatim: "Case reports have documented the development of melanoma following Melanotan II use, as well as rapid changes in moles and pigmented lesions." A separate case report in Actas Dermo-Sifiliográficas describes eruptive dysplastic naevi following melanotan use, including in a teenager with familial atypical multiple mole melanoma syndrome.

Melanotan II stimulates melanocytes. It is associated in case reports with new and changing atypical moles, which are established melanoma precursors.

And causation for melanoma itself is not established. The evidence is case-series level. Cancer Research UK, which reviews this territory carefully, makes no specific melanoma-causation claim: it says the products are not safe to use, have not been tested for safety, quality or effectiveness, and could contain harmful chemicals not listed on the label. What a careful organisation declines to say is informative.

Three further harms circulate widely and we do not state them, because we could not retrieve the papers: an oral mucosal melanoma after nasal-spray use, ischaemic priapism requiring surgical decompression, and posterior reversible encephalopathy syndrome with renal infarction. Unverified means unverified.

Regulatory position

Not approved for any use. Illegal to sell and supply in the UK. Australian regulators warn against melanotan tanning products sold illegally online, including nasal sprays and injectables. Melanotan I and II have been on FDA Import Alert 66-41 since 18 September 2019, with the entry noting the pattern precisely: imported for stated non-human research purposes, then sold on the internet as an unapproved new drug.

In the US it came off Category 2 in April 2026, and FDA says it will hold an advisory committee meeting on it before the end of February 2027. Some vendor pages present the US position as contested. It is not, and removal from Category 2 has never meant permission.

The nasal sprays

The nasal spray is the current enforcement problem in the UK and Australia, and it is worth understanding why it spreads: no needle, no visible administration, and a mental model that a spray must be gentler than an injection. Nothing about the receptor pharmacology changes with the delivery device.