Melanotan II: Research, Mole and Melanoma Reports, PH Status

Abstract still life: a warm bronze metallic curve casting a long shadow across pale sand, dusk light — **Melanotan II.** Illustration, not a product photo.

Research compound. Not approved by FDA Philippines for human use unless stated. Nothing here is a dosing recommendation or medical advice.

What it is

Melanotan II is a small, ring-shaped synthetic version of alpha-melanocyte-stimulating hormone (alpha-MSH), developed at the University of Arizona alongside melanotan I. The goal was a sunless tan that could protect fair skin from UV damage.

Early human testing showed it also produced erections. The two compounds then went separate ways. Melanotan I became the approved medicine afamelanotide. The arousal effect was spun off into PT-141 (bremelanotide), which reached FDA approval. Melanotan II itself was never developed into a medicine, but it is widely sold online as a "tan jab" or nasal spray.

How it works

Melanotan II activates several melanocortin receptors at once, and each explains one of its effects:

MC1R on skin pigment cells drives eumelanin production, the tan.
MC4R and MC3R in the brain influence sexual arousal and appetite. This is the source of the spontaneous erections and appetite effects.
MC5R is found on exocrine glands; its role in humans is less clear.

That lack of selectivity is the core problem. You cannot get the tan without the brain effects, or the arousal without stimulating every melanocyte in the skin, including those in existing moles.

What the research found

Human trials. The published human data is small and from the 1990s.

Dorr and colleagues (1996) ran a pilot phase 1 clinical study of melanotan II as a tanning agent.
Wessells and colleagues (1998) ran a double-blind, placebo-controlled crossover study in men with psychogenic erectile dysfunction; as the paper's title states, the peptide initiated erections.

These were small, short studies. No trial tested repeated tanning courses for months, and none measured skin cancer outcomes.

Case reports. Since 2009, dermatology journals have published a steady series of cases:

New crops of moles (eruptive naevi), including one 25-year-old man who developed more than 100 new moles, many atypical, after a four-week course; several were severely dysplastic on biopsy (Hueso-Gabriel, 2012).
Existing moles changing shape and colour after use, reported in several cases between 2009 and 2011.
Melanoma diagnosed in users, including a 20-year-old woman with fair skin who had injected melanotan II for three to four weeks alongside sunbed use, around three months before her melanoma was removed (Hjuler and Lorentzen, 2014).

Most reported patients had fair skin and also used sunbeds, so the peptide cannot be separated from UV exposure. Case reports cannot prove cause. They do show the pattern dermatologists worry about: stimulating every melanocyte makes atypical moles darker, more numerous and harder to monitor.

Side effects and regulator warnings

The US FDA's compounding safety list summarises the published case literature on melanotan II as including melanoma, posterior reversible encephalopathy syndrome (PRES, a form of brain swelling with headache, confusion and seizures), sympathomimetic toxicity and priapism. Darkening and change in existing moles is the thread running through the dermatology case reports.

Regulators have been consistent:

UK. The MHRA has called the "tan jab" an unlicensed medicine that may not be safe, and it is illegal to sell or supply in the UK.
Australia. No melanotan II product is approved for supply. In August 2026 the TGA issued an urgent warning after seized nasal sprays labelled 30 mg contained between 22 and 54 mg per bottle, and fined a supplier over A$100,000.
United States. Melanotan II was placed on FDA's list of compounding substances raising significant safety concerns. It was withdrawn from that list in April 2026 after the nominations were withdrawn, which does not make it an approved or legal compounding ingredient.

The TGA finding is a reminder that dose labels on unregulated product can be far off, which adds risk on top of the drug itself.

Compound	Receptors	Status
Melanotan II	MC1R, MC3R, MC4R, MC5R	Never approved; regulator warnings
Melanotan I	Mainly MC1R	Approved as Scenesse for EPP
PT-141	Mainly MC4R, MC3R	Approved as Vyleesi for HSDD

Status in the Philippines

Melanotan II is not registered with FDA Philippines and cannot legally be marketed as a drug or cosmetic. It is not a controlled substance under RA 9165. Demand is low: most Filipino skin is Fitzpatrick type III to V, and the local market pushes towards lightening, not tanning. Where it does circulate, it is usually for the libido effect, where the approved alternative abroad is PT-141. Anyone who has used it and notices new, changing or dark moles should see a dermatologist.

Storage

Lyophilised powder is best kept refrigerated and away from light. After reconstitution, store at 2 to 8°C. See the beginner guide for handling basics.

Common questions

Is melanotan II safe?

It has never been approved, so there is no controlled long-term safety data. Published case reports describe new and changing moles and melanomas in users, and the US FDA has cited melanoma, a brain-swelling syndrome called PRES, sympathomimetic toxicity and priapism among reported serious events.

Can melanotan II cause melanoma?

Case reports describe melanomas diagnosed months after melanotan II use, usually in fair-skinned people who also used sunbeds. Case reports cannot prove cause, but dermatologists and regulators treat it as a real concern.

What is the difference between melanotan II and PT-141?

PT-141 (bremelanotide) was developed from melanotan II to keep the effect on desire while reducing the tanning action. PT-141 went through phase 3 trials and was FDA-approved in 2019; melanotan II never was.

Is melanotan II legal in the Philippines?

It is not registered with FDA Philippines, so it cannot legally be sold as a medicine or cosmetic. It is not a scheduled controlled substance.