# Melanotan 2 Effects, Reviews & Safety: What People Report > Melanotan 2 effects and reviews: the tanning, appetite, and libido effects users report (anecdotal), and the cited safety cautions — moles and melanoma, priapism, kidney and muscle injury. The benefits and side effects the research-use community describes — labeled for what they are — set beside the safety signals the published literature has actually documented. ## The short version People use Melanotan 2 mainly to tan fast with little sun. Most also notice it kills their appetite, and many men get a strong, often unprompted, sex drive. Those are the draws. The trade-offs that come with them are nausea, facial flushing, a run-down feeling, and — the one that sends people to a doctor — moles that darken or appear new. This page does two things and keeps them apart. First, what users themselves report — useful, but anecdotal and uncontrolled. Second, what the published medical literature has documented: the serious case reports of prolonged painful erections, muscle and kidney injury, and melanoma, plus the reasons doctors and regulators warn against it. Melanotan 2 is approved nowhere, and nothing here is a dose or an instruction — it is a plain reading of effects and risks. ## What people report **These are effects reported by the research-use community and in published surveys of online discussion — anecdotal, not clinical evidence, and not verified by controlled trials.** They are described here plainly and without any doses, because an honest review names what people actually experience. **Benefits people seek** - **A rapid, deep tan with little or no sun.** Very commonly reported as the entire reason for use: skin darkening within days, and a deeper color reached with far less sun or sunbed time than otherwise [22]. - **Reduced appetite, and sometimes weight loss.** Very commonly reported, often from the first dose — a marked drop in hunger within the first hour, with some describing weight loss [22]. - **Higher libido and spontaneous erections (men).** Commonly reported by men, often beginning with the first or second dose: a sudden surge in sex drive and unprompted erections. Women also report heightened arousal [22]. - **Cosmetic satisfaction and confidence.** Commonly cited as the reason people continue despite side effects; some discussions note it can shade into preoccupation with appearance [22]. **The unpleasant and the worrying** - **Nausea, sometimes vomiting.** Very commonly reported, typically within the first hour and worst in the early days, often easing as use continues [22]. - **Facial flushing and feeling hot.** Commonly reported soon after a dose — the face going red and warm, usually short-lived [16]. - **Fatigue and lethargy** — the 'melanotan flu.' Commonly reported when starting out: a run-down, flu-like tiredness bundled with nausea [22]. - **Spontaneous stretching and yawning.** Frequently reported soon after a dose; described as odd but harmless [22]. - **Darkening of existing moles and freckles.** Very commonly reported, often the first visible sign of activity, with spots standing out sharply [16]. - **New moles appearing.** A frequent and alarming report among longer-term users — brand-new spots, sometimes many at once, which is often what prompts a doctor visit [16]. - **Uneven, blotchy, or unnaturally long-lasting tan.** Frequently reported as a downside that builds over time, with patchy color, an orange or grey cast, and pigment lingering for weeks to months after stopping [22]. - **Darkening of lips, gums, scars, and genital skin**, and **injection-site reactions** (redness, swelling, small lumps), are also commonly reported [16]. A recurring user belief is that the deeper color protects against burning. Treat this as a belief, not a demonstrated protection — many still report burning when sun exposure is overdone [22]. None of the above is a controlled finding; the cited safety section below is where the documented medical evidence lives. ## Safety & cautions Each caution below is grounded in the published literature and cited. These are documented associations and mechanism-based concerns, not a complete or quantified risk profile. **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 [16][20], and dermoscopy studies show measurable changes in melanocytic lesions during use [21]. Multiple case reports document melanoma and melanoma in situ arising in users [25][26]. The long-term melanoma risk is not established, but any new or changing mole during or after use warrants prompt dermatological assessment, especially alongside UV or sunbed exposure [27]. **Rhabdomyolysis and acute kidney injury.** A published case links Melanotan 2 injection to systemic toxicity with rhabdomyolysis — severe muscle breakdown that can poison the kidneys [17] — and a separate case with literature review describes renal infarction associated with its use, proposing both thrombotic and direct toxic mechanisms [4]. These indicate potential for serious muscle and kidney injury that is not fully understood. **Priapism — a prolonged, painful erection.** Because melanocortin agonism promotes erections, several case reports describe priapism following melanotan tanning injections, including after apparent overdose [18][19][24]. Priapism is a urological emergency that can cause permanent damage 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 [23], consistent with the compound's reported effects on blood pressure and vascular tone. **Nausea and cardiovascular (pressor) effects.** Preclinical work on the hemodynamic actions of alpha-MSH analogs shows melanocortin agonists can raise blood pressure, an effect worsened in animals by impaired nitric-oxide signaling [28][29]. Together with the very commonly reported nausea, this points to meaningful cardiovascular and gastrointestinal effects that are poorly characterized in humans using unregulated product. **Unregulated product — contamination and unknown content.** Analytical studies of melanotan products bought online repeatedly find inaccurate labeling, variable or unverifiable peptide content, and impurities, and the compound appears in surveys of falsified injectables [30][31][32]. With no quality control, a buyer cannot know the actual identity, dose, purity, or sterility of what is in the vial — which compounds every other risk. **No approval, unknown long-term safety, and not a substitute for approved drugs.** Melanotan 2 has never been approved by any regulator, and development did not complete late-phase trials, so long-term human safety is unknown; regulators and dermatology bodies have specifically warned against it [33][34]. It is sometimes confused with afamelanotide (an approved melanocortin therapy for erythropoietic protoporphyria) and with the separately approved sexual-function melanocortin agonist derived from this family — but those approvals and their trial-safety data do not extend to Melanotan 2 [35][36]. ## Then and now Melanotan 2 was designed in the late 1980s as a superpotent analog of alpha-MSH, intended to promote tanning and photoprotection and so potentially reduce skin-cancer risk [33]. Early human work — including a pilot Phase I study — showed it could darken skin, and the observation that it also triggered erections led both to a small study in men with erectile dysfunction and to the development of the spin-off agonist bremelanotide (PT-141) for sexual dysfunction [2][36]. The original tanning program never reached the market. From the mid-2000s an illicit trade emerged, selling the peptide online as unlicensed 'sun-tan jabs' or the 'Barbie drug' despite repeated warnings from regulators and dermatologists [4][37]. It has never held a sanctioned medical or cosmetic use, and it remains an unapproved research chemical today [33]. --- A mechanism-first reading of the Melanotan 2 literature — reporting what the studies measured, not prescribing what anyone should do.