TL;DR

• Despite the hype, Melanotan II is not a dietary supplement. It’s an unapproved drug everywhere that matters in 2025 (NZ, US, UK, AU).
• Yes, it can darken skin. But side effects are common (nausea, flushing, mole changes) and quality is a big unknown with online products.
• In New Zealand, it’s illegal to sell or import for personal use. Medsafe and other regulators have issued repeated warnings.
• If your goal is a quick glow, go with DHA spray tans or pro tanning services. If your goal is sunburn protection, use SPF 50+, UPF clothing, and shade-these actually work.
• Used it already? Watch your moles, photograph any changes, and talk to your GP or a dermatologist. Report side effects to CARM.

What Melanotan-II really is (and what it isn’t)

I live in Wellington, and every summer the same question pops up at barbecues and on the school sidelines: “Is this Melanotan stuff legit?” I get why it tempts people. A deeper tan without baking in the sun sounds like having your pavlova and eating it too. But let’s cut through the marketing.

Melanotan-II (often called MT-II) is a lab-made copycat of a hormone your body uses to make melanin-the pigment that darkens your skin. It nudges specific receptors (mainly MC1R) that tell your pigment cells to produce more color. That part is real: small clinical studies and lots of user reports show it can darken skin and sometimes reduce how quickly you burn.

Here’s what it is not: a dietary supplement. “Dietary supplement” is a legal category for vitamins, minerals, and similar products taken by mouth. Melanotan-II is a pharmacologically active peptide typically sold as an injectable or a nasal spray. Regulators treat it as an unapproved medicine, not a supplement powder you add to a smoothie.

Worth knowing: this class of drugs has cousins that are approved-but for tightly defined medical uses. Afamelanotide (brand Scenesse) is an implant approved for people with erythropoietic protoporphyria to reduce light-triggered pain. Bremelanotide (brand Vyleesi) is approved for a specific sexual health condition in premenopausal women. Neither is approved for tanning, and neither is Melanotan-II.

So yes, MT-II can push pigment production. But it also acts on other receptors (like MC4R), which is why some men report unexpected erections and some people feel nauseous or flushed. You’re not just tanning one switch; you’re nudging a whole system.

Evidence, side effects, and the 2025 legal picture

Let’s be fair about efficacy. Short-term studies show Melanotan-II can increase skin pigmentation and raise tanning response with less UV exposure than usual. That’s the attraction. But the safety and quality trade-offs are real.

What people commonly report:

• Nausea, vomiting, and facial flushing (very common early on)
• Loss of appetite, headache, fatigue, dizziness
• Darkening of existing moles and freckles; sometimes new, irregular spots
• Injection site pain, swelling, or infection if sterility is poor
• In men: spontaneous erections; rarely, prolonged painful erections (priapism)

What clinicians and case reports worry about:

• Mole changes that can mask or mimic melanoma
• Possible links between use and melanoma diagnosis in case reports; cause-and-effect isn’t proven, but the signal is concerning
• Rare but serious events like pancreatitis or kidney issues, and contaminated vials causing infections

Two extra problems muddy the water:

1. Quality control: Products bought online are often mislabeled or impure. Independent analyses have found variable potency, microbial contamination, or no active ingredient at all.
2. No approved dosing standard: Because it isn’t approved, there’s no official, tested dosing guidance or safety monitoring. People copy internet protocols. That’s guesswork.

Regulators (as of September 2025) are crystal clear. Here’s the status in major English-speaking markets:

Primary sources: Safety advisories and enforcement notices from Medsafe (NZ), the US Food and Drug Administration (FDA), the Australian Therapeutic Goods Administration (TGA), and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Clinically, concerns about mole changes and melanoma come from dermatology case reports and reviews in journals such as BMJ Case Reports and the Australasian Journal of Dermatology.

Bottom line on safety: if you’re seeing a tan with little sun, the drug is doing something potent. That potency comes with a side-effect profile you would normally accept only when a doctor is treating a diagnosed condition and monitoring you. Here, you don’t get that safety net.

Better ways to get the result you want (without gambling)

People usually chase MT-II for one of three reasons: to look more tanned, to burn less in the sun, or for a side-effect related to sexual function. You can address each goal more safely.

If you want a deeper look fast:

• Use DHA spray tans or mousse. Dihydroxyacetone reacts with the top layer of your skin to create a natural-looking bronze. Good services in NZ can customise shade so you don’t go orange. It fades in 5-10 days.
• Pro tip: Exfoliate the night before, moisturise dry spots (elbows, knees), and avoid tight clothes for a few hours after application to prevent streaks.

If you want to burn less this summer:

• SPF 50+ broad-spectrum sunscreen. SPF 50 blocks about 98% of UVB; SPF 30 is about 97%. Reapply every 2 hours and after swimming.
• UPF-rated clothing, a wide-brim hat, and good sunglasses. Shade between 10am and 4pm, especially in the NZ sun, which is no joke.
• Consistency beats heroics: a little sunscreen, often, is better than one perfect coat at 9am.

If you’re curious because of the sexual side-effects:

• See your GP. Erectile dysfunction often has fixable causes (sleep, stress, blood pressure, meds). Evidence-based treatments exist.
• For low sexual desire in women, bremelanotide is an approved option for specific cases under medical care. Different drug, proper oversight.

Red flags when you see MT-II sold online:

• “Research chemical, not for human use” but paired with dosing tips on the same page
• Claims of being “pharmaceutical grade” without a licensed manufacturer
• Vials shipped warm, no batch numbers, no patient leaflet, no sterility indicators
• In NZ, any site offering “free shipping” domestically is already ignoring the law; that should tell you about their standards

Quick decision guide:

• If your event is in a week: get a spray tan or a professional airbrush session.
• If your skin is very fair (Fitzpatrick I-II): MT-II won’t change your genetics. Prioritise sun safety, and consider a lighter spray tan tone for a natural look.
• If you have lots of moles or a family history of melanoma: steer clear of anything that darkens lesions or masks changes-regular skin checks are your friend.

Personal note: I’m a dad (Hugo’s my little shadow at Lyall Bay), and like most parents here, I’m laser-focused on keeping our summer simple and safe. A bottle of SPF, a rash shirt, and a decent fake tan do the job without the roulette.

Answers to common questions, plus next steps if you’ve already used it

Mini‑FAQ

• Is Melanotan-II legal in New Zealand? No. It’s an unapproved medicine. Selling or importing it is illegal. Medsafe has seized shipments and warned repeatedly.
• Is it a dietary supplement? No. It’s a synthetic drug, usually injected or used as a nasal spray. Calling it a supplement is marketing spin.
• Does it work without sun? It can darken skin on its own, but exposure to UV often amplifies the effect-which brings the usual UV risks back into play.
• Will it stop me burning? It may raise your tanning threshold, but it is not a sunblock. You still need SPF, clothing, and shade.
• Can it cause melanoma? We don’t have definitive proof of causation. There are concerning case reports of melanoma or changing moles after use. Because melanoma risk is a serious matter in NZ, clinicians advise avoiding it.
• Is the nasal spray safer than injections? Not proven. You’re still absorbing an unapproved drug with unknown purity and dosing. Side effects are reported with both routes.
• How long do effects last? The tan can build over weeks and fade over several weeks, but experiences vary. Without controlled dosing standards, it’s unpredictable.
• Can I drink alcohol with it? There’s no approved label or clear study guidance. People report worse nausea when mixing. The bigger issue is you’re taking an unapproved drug with unknown interactions.

What to do if you’ve already used Melanotan-II:

1. Do a skin check in good light. Look for new moles, changing borders, colors, itching, or bleeding. Use the ABCDE rule (Asymmetry, Border, Color, Diameter, Evolving).
2. Photograph any spots that worry you. Re-check in 2-4 weeks. If you see changes, book a GP or dermatology appointment sooner rather than later.
3. Log side effects. Nausea, headaches, flushing, erections-write down what, when, and how long. If symptoms are severe (e.g., chest pain, severe abdominal pain, prolonged erection), seek urgent care.
4. Tell your doctor what you took, how, and when. Don’t worry about judgment; clinicians would much rather have the facts.
5. Report to CARM (NZ’s Centre for Adverse Reactions Monitoring). These reports help flag patterns and protect others.

Safety checklist before you decide anything:

• Have I looked at regulator warnings (Medsafe, FDA, TGA, MHRA)?
• Am I okay with a product that has no approved dosing, purity checks, or medical oversight?
• Is there a safer way to get the same outcome (spray tan, SPF, dermatology consult)?
• Do I or my family have a history of melanoma? If yes, step away.

For the data-minded, here’s a snapshot of the regulatory landscape you can rely on when weighing risks:

Why regulators are so aligned: You’re dealing with an active drug that changes pigmentation, can alter moles, and is widely sold without the guardrails that make medicines safe-manufacturing standards, proper dosing, and post-market surveillance. That’s not nitpicking; it’s basic patient safety.

If your real goal is confidence, not just color, here’s a simple plan that works in the real world:

• Book a pro spray tan the day before your event.
• Keep SPF 50+ and a lip balm with SPF in your bag. Reapply without thinking about it.
• Wear a UPF shirt for the midday school pick-up or when you’re out with the kids at the park.
• Train 2-3 times a week, sleep 7+ hours, hydrate. You’ll look better in every light, tan or not.

Primary sources you can ask your clinician about: Medsafe New Zealand advisories on melanotan products; FDA consumer warnings on unapproved tanning injections; TGA public statements on melanotan; MHRA safety warnings; dermatology literature reviewing mole changes and melanoma case reports after melanotan exposure.