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Melanotan II

Unlicensed; regulators in several countries have warned since 2008.

An unlicensed injection or nasal spray that darkens skin by switching on pigment cells. It also acts on receptors for appetite and sexual arousal. Regulators in several countries have warned against it for more than fifteen years. A , also called MT-II, Tanning injection and Nasal tanner.

C50H69N15O91,024.2 g/mol7 amino acids

What the evidence shows

Early
Early studies showed a tan within about five doses.
Early
Seen in small early studies in men. That work led to bremelanotide, which was later licensed for low desire in women, not for erections.
Appetite suppression
Lab only
No controlled trials.

Side effects and risks

Serious
New and darker moles, and case reports of melanoma. A causal link is unproven, partly because users also seek more sun.
Serious
Case reports of prolonged painful erections, muscle breakdown, kidney damage and brain swelling.
Serious
Unregulated products. Nasal sprays are often sold as cosmetics to dodge medicines law.
Common
Nausea, flushing, loss of appetite and spontaneous erections.

Who should avoid it: Everyone, above all people with many moles, fair skin that burns, or a personal or family history of melanoma.

How it works

Where it acts
Several melanocortin receptors: MC1 in skin, and MC3 and MC4 in the brain.
What it changes
Darker skin, plus effects on appetite and sexual arousal.
What people notice
Tanning, nausea, flushing, unwanted erections, and new or darkening moles.

How it has been given

No established dose. Users inject it under the skin or use nasal sprays. No trial data support the doses sold.

Getting it in the United States

This describes what people do. It is not advice. The decision is yours.

What users report

Recurring themes in public forum posts, unverified and with no comparison group.

Reported benefits

  • Deep tan with little sun
  • Higher libido for some

Reported problems

  • Nausea and flushing after each dose
  • New freckles and darker moles
  • Patchy color; unwanted erections

The mole changes people describe are the reason dermatologists warn against it.

More contextCase reports, what public figures say, videos and articles and the chemistry

Case reports

From journals, regulators and studies of users. One case proves little.

Harm reportedcase report - 1 person - 2020

A healthy 45-year-old man who self-injected melanotan II for six months had an infarction of about half of one kidney with high blood pressure. No clot source was found. Kidney function was slightly reduced two months later.

Source: CEN Case Reports, 2020

Harm reportedcase report - 1 person - 2019

A man came to a UK urology emergency unit with low-flow priapism after injecting melanotan. Drainage and a drug injection avoided shunt surgery. Erectile function had not returned at four weeks.

Source: BMJ Case Reports, 2019

Harm reportednews-reported case - 1 person - 2025

A UK woman was taken to hospital struggling to breathe after a severe reaction to an unlicensed nasal tanning spray bought online. Trading standards used her account in a public warning campaign.

Source: Chartered Trading Standards Institute, 2025-05

Rapidly changing moles after online tanning injections

Harm reportedcase report - 2 people - 2009

UK dermatologists described two patients with rapidly changing moles after injecting unlicensed tanning peptides bought online. Both had fair, sun-reactive skin, used sunbeds and had a much darker tan than expected.

Source: BMJ, 2009

What experts and influencers say

Recommend0
Mixed view2
Warn against12

Paraphrased from the linked sources.

Calls the craze unfounded. He found no randomized human trial showing the advertised benefits for any of the unapproved peptides he reviewed, and warns about stacking several at once. He points to animal work in which TB-500 sped up dormant tumor growth and to a theoretical cancer concern with growth-hormone peptides and BPC-157. He treats the GLP-1 drugs as the well-studied exception.

Source: Eric Topol, "The Peptide Craze", Jul 2025, Associated Press, Nov 2025

Eric TopolWebsiteWarns against

Cardiologist, Scripps Research

Devoted a full episode in 2024 to how these peptides are thought to work and how people use them. He presents possible benefits for healing, growth hormone, sleep and libido, and also says most of the data comes from animals, that black-market products may be contaminated, and that anyone with a tumor or cancer concern should avoid peptides that promote growth or new blood vessels.

Source: Huberman Lab episode, 1 Apr 2024

Andrew HubermanInstagramMixed view

Neuroscientist and podcast host

Judges each peptide separately. He sees no use case for BPC-157: no human evidence, animal data mostly from one lab, and claims that keep widening. He is not a proponent of growth-hormone peptides such as CJC-1295, citing short studies and no long-term safety data. He says elamipretide makes sense only for Barth syndrome, that the risks of melanotan II probably outweigh a cosmetic tan, and that he stopped prescribing bremelanotide. He regards the GLP-1 drugs as clearly effective.

Source: Peter Attia, AMA 83 show notes, 2026

Peter AttiaInstagramMixed view

Physician and podcast host

Watch and read

Explainers, reporting and podcasts worth your time. Summaries are ours. No sellers.

Video - STAT - 8 May 2025 - 2 min

Inside the world of internet peptides

Alex Hogan, STAT

Short video on why people try internet peptides for tanning, injuries and weight loss, noting many are sold as research chemicals with unproven medical use.

Two-minute primer on the online peptide scene

Article - PolitiFact via PBS NewsHour - 14 Mar 2026

What are peptides, and are they safe? Here's what to know

Grace Abels, PolitiFact reporter

A general peptide primer that lists Melanotan among unapproved products and notes most peptides lack placebo-controlled human trials.

General primer that names Melanotan among unapproved products

Amino-acid sequence

Water-avoidingPositive chargeNegative charge

Positions 2 and 7 are joined by a side-chain ring, closing a ring. Striped tiles are mirror-image (D) amino acids, which resist breakdown. Ringed tiles are amino acids not found in natural proteins.

Questions people ask

Is Melanotan II safe?

It is unlicensed and carries serious risks: new and darker moles, case reports of melanoma, prolonged painful erections, muscle breakdown, kidney damage and brain swelling. A causal link to melanoma is unproven, partly because users also seek more sun.

What are the side effects of Melanotan II?

Nausea, flushing, loss of appetite and spontaneous erections are common. Users also report new freckles, darker moles and patchy color.

Are tanning nasal sprays the same as Melanotan?

Melanotan II is sold both as an injection and as a nasal spray. Nasal sprays are often sold as cosmetics to dodge medicines law, and the products are unregulated.

Is Melanotan legal in the UK?

Selling medicines containing melanotan is illegal in the UK, and Trading Standards warned about nasal tanners in May 2025.

Is Melanotan legal in Australia?

The TGA treats it as prescription-only, and a supplier in New South Wales was fined over A$101,000 in August 2026.

Your notebook

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Sources

  1. DermNet: Melanotan II
  2. FDA: bulk substances that may present significant safety risks
  3. ITV News: Trading Standards warning on nasal tanning sprays (16 May 2025)
  4. Pharmacy Daily: TGA peptide and melanotan raids (18 Aug 2026)
  5. Health Canada: unauthorized injectable peptides (1 Aug 2025)

Structure: PubChem