# Melanotan 2 Effects, Reviews, and Safety: What People Report and What Studies Found > Melanotan 2 effects span tanning, appetite, libido, and a list of documented harms. A plain-English account of what users report (anecdotal) and what the cited safety literature shows. The reported upsides, the reported downsides, and the cited harms — kept separate and stated plainly. ## The short version People use **Melanotan 2** mainly to get a deep tan with little sun. They also report less appetite and, in men, a strong rise in sex drive and spontaneous erections. Those are the effects that draw people in. But the same activity produces a long list of downsides: nausea, facial flushing, fatigue, darkening of existing moles, and — most worryingly — brand-new moles appearing during use. The section below separates two very different kinds of information. First, **what people report** — these are community accounts, anecdotal and not from controlled trials. Second, **safety and cautions** — these are grounded in published case reports and studies, and each is cited. The reported effects tell you what users notice; the safety section tells you what the medical literature has documented, including serious harms like melanoma, kidney injury, and prolonged painful erections. ## What people report *The following are effects described by people in the research-use and tanning community. They are **anecdotal, not clinical evidence**, are not verified by controlled trials, and no doses are given here. They are included so readers understand what is actually reported — the appeal and the downsides alike.* **Reported benefits** - **A rapid, deep tan with little or no sun.** This is very commonly described as the whole reason people seek it out — skin darkening noticeably within days, reaching a deeper color with far less time in the sun or on a sunbed. - **Cosmetic satisfaction and confidence.** Many say they feel more attractive with the tan and keep using it for that reason. Some discussions note this can shade into preoccupation with appearance. **Reported mixed effects** (welcomed by some, unwanted by others) - **Reduced appetite and weight loss.** Very commonly reported, often from the first dose — feeling much less hungry, sometimes within the hour, with some reporting weight loss. - **Increased libido and spontaneous erections (men).** Commonly reported by men, often from the first or second use — a sudden surge in sex drive and unprompted erections, sometimes at inconvenient times. Some welcome it; others find it uncomfortable. Women also report heightened arousal. - **Spontaneous stretching and yawning.** A distinctive, frequently mentioned urge to stretch and yawn repeatedly after a dose — described as odd but harmless. - **A belief that the darker tan protects against burning.** Some treat their deeper color as a safety upside. This is a user belief, not demonstrated protection, and many still report burning when they overdo sun exposure. **Reported adverse effects** - **Nausea, sometimes vomiting.** One of the most consistently described effects, typically in the first hour after a dose and worst in the early days, easing as people continue. - **Facial flushing and feeling hot**, usually within minutes to an hour of a dose. - **Darkening of existing moles and freckles**, very commonly reported and often the first visible sign of activity, with spots standing out more sharply than the surrounding skin. - **Appearance of new moles** — a frequent and alarming report among longer-term users, sometimes many at once, which is often what prompts a doctor visit. - **Darkening of face, lips, scars, gums, and genital skin**, which can look conspicuous; some describe new facial patches resembling melasma. - **Fatigue and lethargy** — a run-down, flu-like feeling early in use that many call the "melanotan flu." - **Injection-site reactions** — redness, swelling, itching, bruising, or small lumps, usually described as minor. - **Uneven, blotchy, or unnaturally long-lasting tan**, sometimes with an orange or grey cast, and color that lingers for weeks to months — fading slowly and patchily after stopping, with moles sometimes staying darker than before. ## Melanotan 2 reviews Independent academic work has actually catalogued these self-reports. A qualitative study of online discussion forums analyzed how people describe their Melanotan 2 use, mapping the gap between what they expect and what they experience [22]. A separate analysis of social-media marketing and perceptions of the so-called "Barbie drug" documented how the tan is promoted versus the documented risk [12]. The pattern across both is consistent with the community reports above: tanning and appetite/libido effects pull people in, while nausea, mole changes, and the unregulated nature of the product are the recurring complaints. These remain reported experiences and qualitative findings — not controlled efficacy data. ## Is melanotan 2 safe **Safety & cautions** — each point below is grounded in the published literature and cited. **New, changing, or darkening moles and melanoma risk.** As a non-selective melanocortin agonist acting on MC1R, Melanotan 2 drives melanocyte activity throughout the skin. Case reports describe eruptive new nevi, dysplastic (atypical) moles, and darkening of existing moles after use [13], [14], [15], [16], dermoscopy studies show measurable changes in melanocytic lesions during use [17], and several reports document melanoma and melanoma in situ arising in users [18], [19], [20], [21], [23]. A causal link to melanoma is not proven, but it is a serious case-reported concern — especially with concurrent UV or sunbed exposure. Any new or changing mole during or after use warrants prompt dermatological assessment. **Rhabdomyolysis and acute kidney injury.** A published case links Melanotan 2 injection to systemic toxicity with rhabdomyolysis — severe muscle breakdown [24] — and a separate case and literature review describe renal infarction associated with its use [4]. The mechanisms are not fully understood and may relate to the peptide's effects on blood vessels. **Priapism (prolonged, painful erection).** Because melanocortin agonism promotes erections, several case reports describe priapism following melanotan tanning injections, including after apparent overdose [25], [26], [27]. Priapism is a urological emergency that can permanently damage erectile tissue if not treated quickly. **Posterior reversible encephalopathy syndrome (PRES).** A case report describes PRES — a neurological condition involving brain swelling that can present with headache, seizures, visual disturbance, and high blood pressure — in association with melanotan use [28], consistent with the compound's reported effects on blood pressure. **Nausea and cardiovascular (pressor) effects.** Preclinical work on the hemodynamics of alpha-MSH analogs shows melanocortin agonists can raise blood pressure [29], and animal studies indicate this pressor effect is worsened by impaired nitric-oxide signaling [30]. Together with very commonly reported nausea — which was severe in roughly 13% of subjects at the doses used in controlled studies [31] — this points to meaningful cardiovascular and gastrointestinal effects that are poorly characterized in humans using unregulated product. **Unregulated product: contamination, mislabeling, and unknown content.** Analytical studies of Melanotan 2 bought online repeatedly find inaccurate labeling, variable or unverifiable peptide content, and impurities [32], [33], and the compound appears in surveys of falsified and black-market injectables [34], [35]. Because there is no quality control, a buyer cannot know the actual identity, dose, purity, or sterility of what is in the vial [36], [37], which compounds every other risk. **No regulatory approval and unknown long-term safety.** Melanotan 2 has never been approved for any use, and development never completed late-phase trials, so its long-term safety in humans is unknown [3], [38]. Regulators and dermatology bodies have specifically warned against melanotan tanning products [36], [37]. ## Melanotan 2 dangers in one place The most serious documented dangers, drawn from the cited record above, are: melanoma and melanoma in situ in users [18], [19], [20], [21], [23]; renal infarction [4] and rhabdomyolysis with kidney injury [24]; priapism requiring emergency care [25], [26], [27]; PRES [28]; and the across-the-board uncertainty that comes from injecting an unregulated, often mislabeled product [32], [33]. None of these is a routine cosmetic side effect — they are reasons the medical literature treats Melanotan 2 as a hazardous, unapproved research chemical rather than a tanning product. ## Then and now Melanotan 2 was designed in the late 1980s at the University of Arizona as a superpotent cyclic analog of the natural pigment hormone alpha-MSH, intended to promote tanning and photoprotection and so potentially reduce skin-cancer risk [3]. Early human work included the pilot Phase I tanning study [1] and, after researchers noticed it also triggered erections, a small study in men with erectile dysfunction [2] and the development of a spin-off agonist for sexual dysfunction [39]. The original tanning program never reached the market. From the mid-2000s an illicit trade emerged, with the peptide sold online as unlicensed "sun-tan jabs" or the "Barbie drug" despite repeated warnings from regulators and dermatologists [40], [12]. It remains an unapproved research chemical with no sanctioned medical or cosmetic use [3]. --- An independent, mechanism-first reading of the Melanotan 2 record: the melanocortin pharmacology stated plainly, the small human evidence and the documented harms each cited to source, and no clinic, prescriber, or product behind any of it.