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Not medical advice. The Atlas is not a substitute for a clinician who can examine you.

Melanotan I & II

The Tanning Peptides, Erection and Libido as Side Effects

Evidence grade 2 of 5, Thin. Read how the Atlas grades evidence.

The written rationale for this grade is still being prepared.

FDA
Not FDA-approved; warned against by regulators (FDA, TGA, others)

Reference only. Not medical advice.

What can go wrong

Priapism (prolonged painful erection) is a medical emergency that can cause permanent damage. Other documented effects include nausea, vomiting, flushing, decreased appetite, and darkening/multiplication of moles. Products are unregulated, frequently impure or mislabeled, and injected non-sterilely. Regulators including the FDA, TGA, and MHRA have explicitly warned against Melanotan products.

This is something to take to a clinician. The Atlas can tell you what is known about melanotan i & ii in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.

Melanotan I (afamelanotide) and Melanotan II are synthetic analogs of alpha-melanocyte-stimulating hormone (alpha-MSH) developed to induce skin pigmentation. Melanotan II, in particular, was found in early study to be a potent inducer of male erections, the observation that led directly to the development of bremelanotide (PT-141). Sold illegally online as 'tanning injections,' Melanotan II is not approved for cosmetic or sexual use and has a meaningful adverse-effect and contamination profile.

Bremelanotide's reckless ancestors, bought online to tan, with a sexual side effect.

What people take it for

These are the reasons people give for taking it. They are not effects it has been shown to have.

  • Cosmetic tanning (illegal/unapproved)
  • Off-label libido/erection (unsafe, not recommended)
  • Afamelanotide only: erythropoietic protoporphyria (separate approved drug)

How it is supposed to work

Both are non-selective melanocortin agonists. Activity at MC1R on melanocytes drives melanin production (tanning); activity at central MC4R drives appetite suppression and the pro-sexual/erectile effect. The lack of receptor selectivity is precisely why Melanotan II produces tanning, nausea, and erections together.

The dark side

Because it is non-selective and bought from unregulated sources, Melanotan II combines unpredictable dosing with a broad side-effect spread: priapism (a urologic emergency), nausea/vomiting, flushing, and changes in moles/freckles. Concern about melanoma exists, though a 2021 review suggested much of the observed melanoma risk may reflect sun-seeking behavior in users rather than a direct drug effect. Reports of kidney dysfunction and serious systemic effects exist.

Safety in detail

Melanotan I/II for tanning or sexual use is unapproved and regulator-warned-against. Priapism is a documented emergency. Products are unregulated and frequently impure. This is not safe self-administration.

What people get wrong

  • Often saidMelanotan II is a safe tan-and-libido shortcut

    ActuallyIt is unapproved, can cause priapism, and is sold as unregulated, often impure product. Regulators warn against it.

  • Often saidIt is basically the same as the approved PT-141

    ActuallyBremelanotide was engineered FROM Melanotan II to favor sexual effects and reduce tanning/side effects and went through FDA review; Melanotan II did neither.

Who profits, and who pushes back

Nobody is named here yet, because we have not done that work on this entry. Read that as unfinished. Somebody almost certainly sells this, and somebody almost certainly disputes it. Assume both until we have checked.

At a glance

Melanotan I
afamelanotide; approved (Scenesse) only for the rare disorder EPP, not tanning
Melanotan II
Not approved anywhere for tanning; sold illegally online
Sexual link
Erectogenic side effect drove development of bremelanotide
Regulatory stance
FDA, UK MHRA, Australian TGA warn against use

What this entry does not yet cover

What follows is unfinished work on our side, not a finding about Melanotan I & II. A short entry is not a safe entry.

  • Timeline. We have not built the dated record of research and regulatory events.
  • Cost and market. We have not documented what it sells for or who sells it.
  • Supply chain. We have not mapped where it is made.
  • Who uses it. We have not documented the user groups.
  • What could change. No forward-looking summary yet.
  • How it compares. We have not set it against the alternatives.
  • Children and teenagers. We have not checked what is known about younger people.
  • Where we land. We have not taken a position on this yet.

Sources

The studies below are named and described, but not linked. You cannot open them from here and check our reading against them, which means this page is our summary of the literature rather than a document you can verify. Weigh it accordingly until the links exist.

The studies that matter

  • Early erectogenic observations (Melanotan II)1990s-2000s

    Trials of Melanotan II as a tanning agent noted potent induction of male erections, prompting development of bremelanotide

  • Melanotan/melanoma review2021

    Concluded increased melanoma risk in users may largely reflect greater UV exposure/sun-seeking rather than a direct drug effect