# Melanotan 2 Effects: Reported Benefits, Side Effects & Cautions > Melanotan 2 effects read honestly: the tanning, appetite, libido and mood people report, the nausea and mole changes too, and the cited safety cautions. Is Melanotan 2 safe? An honest reading of the upsides and the downsides — the tan, the appetite drop, the libido, and the nausea, the mole changes, and the serious case reports. ## The short version Melanotan 2 effects fall into two camps that people experience at the same time: things they want, and things they do not. On the wanted side, users report a fast, deep tan with little sun, less appetite (sometimes from the first dose), and — in men especially — a sharp rise in sex drive and unprompted erections. Many simply say they feel more confident with the color. On the unwanted side, the same people report nausea, facial flushing, tiredness, odd spells of yawning and stretching, and injection-site soreness. More seriously, they report moles darkening and brand-new moles appearing. The published record adds rarer but graver events: prolonged painful erections, muscle breakdown, and kidney injury. Below, the community reports come first (clearly labeled as anecdote), then the cited safety cautions. None of this is dosing advice, and no doses appear in the reported-effects section. ## What people report **These are effects reported by the research-use community and in qualitative studies of online discussion — anecdotal, not clinical evidence, and not verified by controlled trials.** They are described here plainly and without any doses. **The effects people seek out** - **A rapid, deep tan with little or no sun.** Very commonly reported as the whole point. Users say skin darkens noticeably within days and that they reach a deeper color with far less time in the sun or on a sunbed. - **Reduced appetite, sometimes weight loss.** Very commonly reported, often within the first hour. People differ on whether they treat the appetite drop as a welcome bonus or an off-putting nuisance. - **Higher 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 the hard-to-control erections uncomfortable. Women also report heightened arousal. - **Cosmetic satisfaction and confidence.** Commonly given as the reason people continue despite side effects; some discussions note it can shade into preoccupation with appearance. **The effects people dislike or fear** - **Nausea, sometimes vomiting.** Very commonly reported, usually within the first hour and worst in the early days, often easing as use continues. - **Facial flushing and feeling hot.** Commonly reported soon after a dose; short-lived but uncomfortable. - **Fatigue and lethargy ("melanotan flu").** Commonly reported when starting out, often bundled with the nausea. - **Spontaneous stretching and yawning.** Frequently reported as an odd-but-harmless urge in the period after a dose. - **Injection-site reactions.** Commonly reported with repeated injections — redness, swelling, itching, bruising, or small lumps, usually minor. - **Darkening of existing moles and freckles.** Very commonly reported, often the first visible sign, with spots standing out more sharply than the surrounding skin. - **New moles appearing.** A frequent and alarming report among longer-term users — brand-new spots, sometimes many at once, which is often what sends people to a doctor. - **Selective darkening of lips, gums, scars, and genital or underarm skin,** sometimes resembling melasma — commonly reported and conspicuous. - **Uneven, blotchy, unnaturally long-lasting color.** Frequently reported, including an orange or grey cast and a tan that fades patchily over weeks to months after stopping, with moles staying darker than before. One belief worth flagging: some users assume a deeper color protects them from burning and stay out longer as a result. That is a user belief, not a demonstrated protection — many still report burning when they overdo the sun. ## Melanotan 2 reviews and reddit reports Searches for melanotan 2 reviews and melanotan 2 reddit threads turn up the same split picture as above: enthusiasm for the tan and the libido alongside steady complaints about nausea, blotchiness, and frightening mole changes. A published qualitative study of online discussion forums captured exactly this gap between marketing and documented risk, with users trading both glowing results and worried accounts of new spots [11]. These accounts are useful as a map of what people experience, but they are not evidence of safety or effectiveness. They are unverified, unattributed, and shaped by who chooses to post. Treat the forum consensus as a hypothesis-generator, not a finding — the controlled human data on Melanotan 2 remains limited to a few small Phase I studies. ## Is Melanotan 2 safe? The cited cautions Is Melanotan 2 safe? The honest answer from the literature is that nobody knows, because the compound never completed the trials that would tell us — and the case reports that do exist describe real harm. What follows is the genuinely useful context, each caution grounded in published work. Several mechanisms below are theoretical or based on single case reports, and are flagged as such. **New, changing, or darkening moles, and melanoma risk.** Because Melanotan 2 drives pigment-cell activity throughout the skin, case reports describe eruptive new moles, atypical (dysplastic) moles, and darkening of existing ones after use; a smaller number of reports document melanoma and melanoma in situ in users, and dermoscopy studies show measurable changes in moles during use [5][6][12][13][14]. Whether the compound causes melanoma is not established, but any new or changing mole during or after use is a reason for prompt dermatological assessment. **Rhabdomyolysis and acute kidney injury.** One published case links Melanotan 2 injection to systemic toxicity with rhabdomyolysis (severe muscle breakdown), and a separate case with literature review describes renal infarction associated with its use; the mechanisms are not fully understood and may relate to the peptide's vascular effects [15][16]. **Priapism (prolonged, painful erection).** Because melanocortin signaling promotes erections, several case reports describe priapism — a prolonged, painful erection — after Melanotan tanning injections, including after apparent overdose [17][18][19]. 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 reversible neurological condition involving brain swelling, which can present with headache, seizures, visual disturbance, and high blood pressure — in association with Melanotan use, consistent with the compound's reported effects on blood pressure [20]. **Blood-pressure (pressor) and cardiovascular effects, plus nausea.** Preclinical work shows melanocortin agonists can raise blood pressure, an effect worsened in animals when nitric-oxide signaling is impaired [21][22]. Together with the very commonly reported nausea, this points to meaningful but poorly characterized cardiovascular and gastrointestinal effects in people using unregulated product. **Unregulated product: contamination, mislabeling, unknown content.** Analyses of Melanotan products bought online repeatedly find inaccurate labeling, variable or unverifiable peptide content, and impurities, and the compound turns up in surveys of falsified injectables [23][24][25]. With no quality control, a buyer cannot know the real identity, dose, purity, or sterility of what is in a vial, which compounds every other risk. **No approval, unknown long-term safety.** Melanotan 2 has never been approved by the FDA or other regulators for any use, and never finished late-phase trials, so its long-term safety is unknown; regulators and dermatology bodies have specifically warned against melanotan tanning products [25][26]. It should be regarded strictly as an unapproved research chemical. **Not a substitute for the approved, distinct melanocortin drugs.** Melanotan 2 is often confused with afamelanotide, an approved melanocortin therapy for the rare condition erythropoietic protoporphyria, and with the separately approved melanocortin agonist for sexual function. Those approvals and their trial safety data do not extend to Melanotan 2, which is a different, unapproved compound used without medical oversight [8][9][26]. ## Then and now: where Melanotan 2 came from Melanotan 2 was designed in the late 1980s by Victor Hruby, Mac Hadley, and colleagues at the University of Arizona as a superpotent cyclic copy of the natural pigment hormone alpha-MSH, meant to promote tanning and photoprotection and so perhaps cut skin-cancer risk [26][8]. Early human work showed it could darken skin, and researchers soon noticed it also triggered erections — which led to a small study in men with erectile difficulty and to the spin-off compound bremelanotide (PT-141) for sexual dysfunction [3][9]. The original tanning program never reached the market. But from the mid-2000s an illicit "melanotan" trade emerged, with the peptide sold online as unlicensed tanning injections — the so-called "Barbie drug" or "sun-tan jabs" — despite repeated warnings from regulators and dermatologists [27][26]. It remains an unapproved research chemical with no sanctioned medical or cosmetic use. --- Field notes on the pigmentation literature — observations recorded, not a tan prescribed.