# Melanotan 2 FAQ: Questions About the Research, Answered

> Melanotan 2 FAQ: what it does for men, the erectile-dysfunction trial results, the doses studied, tanning, mole and kidney safety, and how it compares to PT-141.

## What does Melanotan do for men?

In men, the research records two main effects: skin darkening and erections. The 1996 pilot study of 3 healthy men reported increased facial and body pigmentation plus spontaneous erections lasting 1 to 5 hours after low subcutaneous doses [1]. The erectile effect was then measured directly in a controlled trial [2]. These are study findings, not a use recommendation; Melanotan 2 is not approved.

## Does Melanotan affect erectile function in the research?

Yes, clearly. In a 1998 double-blind, placebo-controlled crossover study of 10 men with psychogenic erectile dysfunction, a single 0.025 mg/kg subcutaneous dose produced clinically apparent erections in 8 of 10 men, with mean firm-rigidity duration of 38.0 minutes versus 3.0 minutes on placebo (p=0.0045) [2]. The mechanism is central melanocortin signaling, not blood-flow action [10].

## Does Melanotan 2 affect female sexual behavior in research?

In animal models, yes. In ovariectomized female rats primed with estradiol and progesterone, intravenous melanotan 2 (1 and 3 mg/kg) increased proceptive solicitation behaviors without affecting lordosis [8]. In women, a functional-MRI study using the related agonist bremelanotide found increased self-reported desire and altered brain activation during erotic stimuli versus placebo [7].

## What is the recommended research dose used in the human studies?

In the published Phase I work, investigators recommended 0.025 mg/kg per day subcutaneously for future studies, after escalating from 0.01 to 0.025-0.03 mg/kg in the 1996 pilot [1]; the controlled erectile-dysfunction studies used a single 0.025 mg/kg subcutaneous dose [2]. This is a study-design fact, not a personal dose — Melanotan 2 has no approved human dose.

## How much Melanotan 2 is used in the published studies?

Human studies used subcutaneous doses around 0.01-0.03 mg/kg [1][2]. Animal studies used very different routes and amounts — for example 0.1-1 nmol microinjected into a brain region in mice [5], or 1-3 mg/kg intravenously in rats [8]. These figures characterize the experiments; they are not instructions and do not translate to human use.

## What were the results in the Melanotan 2 erectile dysfunction trials?

The pivotal small trial found that 8 of 10 men with psychogenic erectile dysfunction achieved clinically apparent erections after a single 0.025 mg/kg subcutaneous dose, with more than 80% tip rigidity lasting a mean of 38.0 minutes versus 3.0 minutes on placebo (p=0.0045); side effects were transient nausea, stretching, and yawning [2]. No large Phase II or III trial has confirmed this at scale [3].

## What is Melanotan 2?

Melanotan 2 is a lab-made cyclic peptide that copies the natural hormone alpha-MSH and activates the melanocortin receptors MC1R-MC5R [3]. Its sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, molecular weight about 1024 daltons [3][14]. It darkens skin, affects appetite, and triggers erections, and it is not approved for any human use.

## What is Melanotan 2 used for in research?

In research it has been studied for pigmentation (skin darkening without UV) [1], sexual function (erections in men and proceptive behavior in female animals) [2][8], and appetite suppression and energy balance (mainly in rodents) [5]. None of these is an approved use; the controlled human data are limited to small Phase I studies [3].

## How does Melanotan 2 work in the body?

It activates the melanocortin receptors. At MC1R on skin cells it raises cAMP and switches on pigment-making genes, darkening skin [1][3]. At MC4R and MC3R in the brain it suppresses appetite and promotes erections through central signaling [3][5][10]. One non-selective peptide hitting all five receptors is why it does several unrelated-seeming things at once [3].

## What is the melanogenesis (MC1R-cAMP-MITF) signaling cascade?

It is the chain of steps that turns a receptor signal into pigment. Melanotan 2 activates MC1R, which raises cAMP, which activates PKA, which switches on the transcription factor MITF, which turns on tyrosinase and other enzymes that build melanin [3]. The result is more eumelanin — the darker, more protective pigment — without needing UV light [1][3].

## Does Melanotan work without sun exposure?

Yes. In the 1996 pilot study, subjects developed measurable facial and body pigmentation from injections alone, with no UV exposure [1]. The peptide acts directly on the pigment receptor on skin cells, so the tanning step does not require sunlight — though users who also use sunbeds add the separate, well-known risks of UV [29].

## How long does it take to tan with Melanotan 2?

In the research, pigmentation was measurable after only about five low doses over roughly a week in the 1996 pilot study [1]. Community reports describe darkening within days [33]. Onset varies with the individual and their baseline skin tone; the research provides timing for its specific dosing schedule, not a general timetable, and these are not use instructions.

## How long does the tan from Melanotan last? Is it permanent?

It is not permanent, but it outlasts the peptide. Because pigment synthesis continues after the molecule clears, color persists for weeks after stopping, then fades — often unevenly, with moles and freckles sometimes staying darker [33]. The peptide itself clears quickly; no validated human half-life has been published [12].

## Does Melanotan cause fat loss?

In animals it reliably reduces food intake, which can drive weight loss. Microinjection of melanotan 2 into the nucleus accumbens cut food consumption and food-seeking in mice without aversion or a change in metabolic rate [5]. Users frequently report reduced appetite [33], but no controlled human weight-loss trial of Melanotan 2 has been completed [3].

## Is Melanotan 2 safe to use?

Its safety is not established, and serious harms are documented in case reports: renal infarction [4], rhabdomyolysis [24], priapism [25], PRES [28], and melanoma in users [21]. It has no regulatory approval and its long-term safety is unknown [29][30]. New or changing moles during use need prompt medical assessment [16]. This site reports the literature; it does not advise use.

## Does Melanotan 2 affect the kidneys?

Case reports raise that concern. A nephrology case report with literature review describes renal infarction most likely attributable to Melanotan 2, proposing both a thrombotic mechanism and possible direct kidney toxicity [4]. A separate case links a melanotan 2 injection to rhabdomyolysis with acute kidney injury [24]. These are individual reports, not trial data, but they are serious.

## Can Melanotan affect the appearance of moles?

Yes, and this is the most consistent safety signal. Because the peptide activates melanocytes throughout the skin, case reports describe darkening of existing moles, eruptive new moles, and atypical (dysplastic) moles during use [16][17][18][19], with dermoscopy showing measurable change [23]. Any new or changing mole warrants prompt dermatological assessment [16].

## What is the difference between Melanotan 1 and Melanotan 2?

Melanotan 1 (afamelanotide) is a linear, relatively MC1R-selective analog approved for the rare light-sensitivity disorder erythropoietic protoporphyria [11]. Melanotan 2 is a cyclic, non-selective analog (MC1R-MC5R) that affects pigment, appetite, and sexual function but is approved nowhere [3]. Same family, different selectivity and very different regulatory status.

## What does the research say about melanotan and erythropoietic protoporphyria (EPP)?

The approved analog Melanotan 1 (afamelanotide), not Melanotan 2, is used for EPP. A long-term observational study of 115 EPP patients receiving repeated afamelanotide implants reported sustained quality-of-life improvement with mostly minor adverse events, predominantly nausea [11]. This evidence applies to afamelanotide in EPP, not to Melanotan 2.

## Is Melanotan 2 legal, and why do regulators warn against it?

Melanotan 2 is not approved by the FDA, EMA, TGA, MHRA, or HPRA for any use, and selling it for human consumption is unlawful in many jurisdictions [3][29]. Regulators warn against melanotan tanning products because of documented harms and because online products are unregulated and often mislabeled [29][30][22]. It is also prohibited in sport under WADA's S0 category.

## What is the difference between Melanotan 2 and PT-141 (bremelanotide)?

PT-141 (bremelanotide) was engineered from the Melanotan 2 scaffold toward MC4R-weighted sexual activity with reduced pigmentation activity, and it reached regulatory approval for a sexual-desire condition in premenopausal women [13][7]. Melanotan 2 is the non-selective parent that also tans skin and is approved nowhere [3]. See the [melanotan 2 vs pt-141](/vs-pt-141) page for the full comparison.

## Where is Melanotan derived from or made?

Melanotan 2 is fully synthetic — made by chemical peptide synthesis, not extracted from any organism [3][14]. It is an engineered analog of the natural peptide alpha-MSH, which the body produces from a precursor protein. It was first designed and synthesized at the University of Arizona in the late 1980s [3][14].

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A charcoal instrument-cluster reading of the Melanotan 2 record — the sexual-function trials logged first, the half-life and receptor data stated as plain gauge values, the priapism, kidney and changing-mole case reports flagged in plain sight; no clinic behind the console and nothing here dosed, injected, prescribed, or sold.