# Melanotan 2 Effects: What People Report and What the Studies Found > Melanotan 2 effects, reported plainly: deep tanning, appetite drop, libido and erections, plus nausea, flushing, and mole changes. Anecdotal reports separated from cited findings. An honest, plain-English account of what people report and what the cited research documents, kept clearly separate. ## Start here People use Melanotan 2 for three things: a fast, deep tan with little sun; a drop in appetite; and, in men, a strong jump in sex drive and spontaneous erections. The effects tend to show up quickly — sometimes from the first dose — which is part of the appeal. But the same dose usually brings nausea, facial flushing, and a strange urge to stretch and yawn, and over time many users report their moles darkening or brand-new moles appearing. The honest state of the evidence: the tanning and erection effects are confirmed in small human studies, the appetite effect is well documented in animals, and the worrying skin and organ effects come from real case reports. Melanotan 2 is not approved for human use, and the products sold online are unregulated. Below, what the community reports is kept strictly apart from what the published studies actually measured. ## What people report **These are effects described by the research-use community — anecdotal, not clinical evidence, and not verified by controlled trials. No doses are given here.** **The effects people chase** - **A rapid, deep tan with little or no sun.** Very commonly reported as the whole reason for using it. People describe skin darkening within days and reaching a deeper color with far less time in the sun or on a sunbed than they could otherwise. - **Less appetite, sometimes weight loss.** Very commonly reported, often within the first hour of a dose. Some treat the reduced hunger as a welcome bonus; others find it off-putting. - **A surge in libido and spontaneous erections (men).** Commonly reported by men, often starting with the first or second dose — sometimes hours later and at inconvenient times. Some welcome it; others find the hard-to-control erections uncomfortable or embarrassing. Women also report heightened arousal. - **Cosmetic satisfaction and confidence.** Commonly cited as the reason people keep using it despite the side effects. Some discussions note this can shade into preoccupation with appearance. **The effects people don't advertise** - **Nausea, sometimes vomiting.** Very commonly reported, usually within the first hour and worst in the early days, often easing as people continue. - **Facial flushing and feeling hot.** Commonly reported within minutes to an hour of a dose; usually short-lived. - **Spontaneous stretching and yawning.** Frequently reported soon after a dose — odd but generally described as harmless. - **Fatigue and lethargy ("melanotan flu").** Commonly reported in the first days, a run-down flu-like feeling that usually fades. - **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 — sometimes many at once, sometimes within a day or two of a dose — and often what prompts a doctor visit. - **Selective darkening of lips, gums, scars, and genital skin**, plus new facial patches resembling melasma. Commonly reported. - **An uneven, blotchy, or unnaturally long-lasting tan**, sometimes with an orange or grey cast, and color that lingers and fades patchily for weeks to months after stopping. Frequently reported, especially as a downside that builds over time. - **Injection-site reactions** — redness, swelling, itching, bruising, or small lumps — commonly reported with repeated injections and usually described as minor. One belief worth flagging: some users assume their deeper color protects them from burning and lets them stay out longer. That is a user belief, not demonstrated protection, and many still report burning when they overdo sun exposure. ## Safety & cautions This is where the genuinely useful context lives. Each caution below is grounded in the published literature and cited. **New, changing, or darkening moles — and melanoma risk.** Because Melanotan 2 drives melanocyte activity throughout the skin, case reports describe eruptive new moles, dysplastic (atypical) moles, and darkening of existing ones after use [11][8][9][10]. Dermoscopy studies document measurable changes in pigmented lesions during use [4], and several case reports describe melanoma and melanoma in situ arising in users [12][13][14]. The long-term melanoma risk is not established, but it is a serious, case-reported concern — heightened by concurrent sun or sunbed exposure. Any new or changing mole during or after use warrants prompt dermatological assessment [15]. **Rhabdomyolysis and acute kidney injury.** A published case links a Melanotan 2 injection to systemic toxicity with rhabdomyolysis — severe muscle breakdown that can poison the kidneys [5] — and a separate case with literature review describes renal infarction (loss of blood supply to kidney tissue) associated with its use [6]. The mechanisms are not fully understood and may relate to the peptide's effects on blood vessels. **Priapism (prolonged, painful erection).** Because melanocortin signaling promotes erections, several case reports describe priapism following melanotan injections, including after apparent overdose [16][17][18]. 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, with headache, seizures, visual disturbance, and high blood pressure — in association with melanotan use [19], consistent with the compound's reported effects on blood pressure. **Blood-pressure and cardiovascular effects.** Preclinical work shows melanocortin agonists can raise blood pressure, an effect worsened in animals with impaired nitric-oxide signaling [20][21]. Combined with the very commonly reported nausea — documented as an aversive effect in animal studies [22] — this points to meaningful cardiovascular and gastrointestinal effects that are poorly characterized in humans using unregulated product. **Unregulated product: contamination, mislabeling, unknown content.** Analytical studies of melanotan products bought online repeatedly find inaccurate labeling, variable or unverifiable peptide content, and impurities [23][24], and the compound turns up in surveys of falsified and black-market injectables [25][26]. With no quality control, a buyer cannot know the real identity, dose, purity, or sterility of what is in the vial — which compounds every other risk. **No regulatory approval and unknown long-term safety.** Melanotan 2 has never been approved by any regulator for any use, and development never completed late-phase trials, so its long-term human safety is unknown [27]. Regulators and dermatology bodies have specifically warned against melanotan tanning products [28][29]. It should be regarded strictly as an unapproved research chemical. ## Melanotan 2 reddit and melanotan 2 reviews Searches for **melanotan 2 reddit** and **melanotan 2 reviews** turn up exactly the pattern above: enthusiasm about the tan and the libido effect, alongside steady reports of nausea, flushing, and — most consistently — moles changing or appearing. A 2021 qualitative study that analyzed online discussion forums found this same gap between the marketing and the documented risk, and a 2025 analysis of social-media marketing reached a similar conclusion [30]. Treat user reports as signals of what to watch for, not as evidence of safety; the controlled human data remain limited to a handful of small Phase I studies. ## Then and now 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 alpha-MSH, intended to promote tanning and photoprotection and so potentially reduce skin-cancer risk [27]. Early human work confirmed it could darken skin [1], and the unexpected erection finding led both to a small erectile-dysfunction study and to the development of a separate, approved melanocortin agonist for sexual dysfunction [3]. The original tanning program never reached the market. From the mid-2000s, an illicit "melanotan" trade emerged, with the peptide sold online as unlicensed tanning injections — the so-called "Barbie drug" — despite repeated warnings from regulators and dermatologists [28][29]. It remains an unapproved research chemical with no sanctioned medical or cosmetic use. --- A forward-looking digest of the melanocortin literature — candid about what Melanotan 2 does and the risks it carries, and not a vendor, clinic, or prescription.