Melanotan II_
Also known as MT-2, MT-II, melanotan 2
A shot for a fast, deep tan, plus libido and appetite effects.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Melanotan II?
Plain language first. The technical label stays, but it never stands alone.Overview
Melanotan II is a broad melanocortin-receptor agonist, hitting several of the same receptors as the tanning and libido hormones. In plain terms: it tans skin fast and also boosts libido and cuts appetite, but hitting so many receptors is why it has more side effects. It is not approved.
What it's used for
A shot that gives a fast, deep tan, plus a libido boost and reduced appetite.
How does Melanotan II work?
What it does in the body, and where.Melanotan II hits several melanocortin receptors at once rather than just the pigment one. Every one of its extra effects, wanted and unwanted, comes from that lack of selectivity.
- 01MC1R produces the tanFaster and at lower doses than Melanotan I.
- 02MC4R produces the libido and appetite effectsThe same receptor PT-141 targets. PT-141 was developed from this molecule specifically to isolate that effect.
- 03Nausea, flushing and spontaneous erections follow from the same breadthThese are not side effects in the usual sense, they are the drug hitting receptors it was never made selective for.
- 04Existing moles darkenAnd there are case reports of new or changing melanocytic lesions. Anything that stimulates melanocytes systemically deserves caution here.
- 05It is not approved anywhereUnlike Melanotan I.
Where this compound is thought to act.
What else is it used for?
Each group carries its own evidence level.Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
Tanning
Research only- Human trialIn an early human study, skin melanin rose in a dose-dependent way, with visible tanning after about five alternate-day doses.
- No dataIt is not approved by the FDA or in Europe, and is linked to nausea, flushing, mole darkening, prolonged erections, and muscle breakdown.
Erections
Research only- Human trialIn a study of 20 men with erectile difficulty, 17 achieved erections without sexual stimulation.
- Human trialIn a placebo-controlled crossover of 10 men, 8 had clinically apparent erections.
- Human trialThis side effect is what led researchers to develop PT-141, which is now FDA-approved.
How much, and do you cycle it?
The range, and whether you take breaks.0.25 up to 1 mg per dose (start low, increase slowly), daily loading, then maintenance. A loading phase, then maintenance, rather than a cycleCommunity practice
Frequent doses until the tan develops, then occasional top-ups to hold it. The structure comes from community practice and follows the pigment rather than any receptor recovery.
How do I dose and price it?
Enter your vial and your dose. Pick a mix. We show the draw and the cost.The vial holds a fixed amount of drug. Adding more water does not make more drug, it just spreads it thinner, so you draw a bigger number on the syringe for the same dose.
Choose your mix
Measuring the water1 mL = one full 100-unit syringe.
Your draw
5 / 100 unitsHow do you store it?
Before mixing, and after.Dry powder in the freezer or fridge. Once mixed, fridge, and use within about a month.
Unmixed lyophilized Melanotan II keeps for a long time cold. Once you add water the clock starts: most reconstituted vials hold up for roughly 28 to 30 days at fridge temperature. Keep it out of light, and do not freeze it after mixing.
What are the side effects and cautions?
Known cautions and warnings for this compound.22 July 2026Not approved in any country and not permitted in pharmacy compounding. The UK regulator issued a public warning in 2009 and the FDA has sent warning letters to US distributors. Published case reports link it to melanoma, eruptive and atypical moles, ischemic priapism requiring surgery, muscle breakdown, kidney infarction, and a serious brain condition called posterior reversible encephalopathy syndrome. Whether it directly causes melanoma is unresolved, since users also tend to seek more sun, but the mole changes are consistently documented. Separately, testing of gray-market vials found actual peptide content ranging from about 4.3 to 8.8 mg in vials labelled 10 mg, so the dose you think you are taking may not be the dose you are taking.
Who should avoid it
- Any history of skin cancer or melanoma
- Numerous, large, or atypical moles
- Pregnancy
- High blood pressure or heart problems, since it can raise blood pressure and heart rate
- It is not approved anywhere and is not permitted in pharmacy compounding, so nobody is screening you for any of the above
Stop and get help
- Any mole that changes in size, shape, or colour, or starts to bleed or itch
- An erection lasting more than four hours, which has required surgery in reported cases
- Severe muscle pain with dark or cola-coloured urine, which can signal muscle breakdown damaging the kidneys
- Severe headache with confusion, vision changes, or seizures
- A racing heart, sweating, and severe anxiety shortly after injecting
- Signs of an allergic reaction such as face or throat swelling, hives, or trouble breathing
Common effects
- Nausea, especially in the first few doses
- Facial flushing and yawning
- Darkening of skin, moles, and freckles, which is the intended effect but also the main concern
- New moles appearing, and existing ones becoming irregular
- Loss of appetite
- Spontaneous erections in men
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Melanotan II approved?
And where the numbers on this page come from.No. Not FDA-approved.
Not approved in any country and not permitted in pharmacy compounding. The UK regulator issued a public warning in 2009 and the FDA has sent warning letters to US distributors. Published case reports link it to melanoma, eruptive and atypical moles, ischemic priapism requiring surgery, muscle breakdown, kidney infarction, and a serious brain condition called posterior reversible encephalopathy syndrome. Whether it directly causes melanoma is unresolved, since users also tend to seek more sun, but the mole changes are consistently documented. Separately, testing of gray-market vials found actual peptide content ranging from about 4.3 to 8.8 mg in vials labelled 10 mg, so the dose you think you are taking may not be the dose you are taking.
- DoseFrom research and community reports. No regulator has reviewed this dose.
- Vial sizeFrom what vendors typically list; not a recommendation.
- Sources
- Reviewed22 July 2026
What else is like Melanotan II?
Others in Weight loss and metabolic, side by side.If you're weighing Melanotan II, it's worth reading Semaglutide, Tirzepatide, and Retatrutide in the same class.
A shot for a fast, deep tan, plus libido and appetite effects.
- Dose
- 0.25 up to 1 mg per dose (start low, increase slowly)
- How often
- Daily loading, then maintenance
The drug in Ozempic and Wegovy: a weekly shot that curbs hunger for steady weight loss.
- Dose
- 0.25 up to 2.4 mg per week (start low, increase slowly)
- How often
- Weekly
The drug in Mounjaro and Zepbound: a weekly shot for major weight loss and blood sugar.
- Dose
- 2.5 up to 15 mg per week (start low, increase slowly)
- How often
- Weekly
An experimental weekly shot with some of the biggest weight-loss numbers yet in trials.
- Dose
- 1 up to 12 mg per dose (start low, increase slowly)
- How often
- Weekly
10What these words mean
Show glossary +
What these words mean
- Titrate
- Starting at a low dose and increasing it slowly over time so your body adjusts and side effects stay mild.
- Subcutaneous
- An injection just under the skin, into the fat layer, usually with a short, thin insulin needle.
- Intramuscular (IM)
- An injection into a muscle, using a longer needle.
- Reconstitution
- Mixing a powdered peptide with liquid (bacteriostatic water) so it can be drawn into a syringe.
- Bacteriostatic water
- Sterile water with a tiny amount of preservative, used to mix powdered peptides.
- Concentration
- How strong the mixed peptide is, in milligrams per milliliter (mg/mL). More water makes it weaker; less water makes it stronger.
- Units (on the syringe)
- The marks on an insulin syringe. 100 units equals 1 mL. They measure how much liquid you draw, not the dose in milligrams.
- mcg and mg
- Units of dose. 1 milligram (mg) equals 1,000 micrograms (mcg).
- GLP-1
- A natural gut hormone that lowers appetite and blood sugar. Drugs that copy it, like semaglutide, are used for weight loss.
- Growth hormone secretagogue
- A compound that nudges your body to release more of its own growth hormone, rather than injecting the hormone itself.
- Half-life
- How long a compound stays active in your body. A longer half-life means you inject less often.
- Peptide vs small molecule
- A peptide is a short chain of amino acids. A few items here (like MK-677 or methylene blue) are small molecules, not true peptides, but people use them the same way.
- Research only
- No approved dose or use in people. Sold for research and not reviewed by the FDA for safety or quality.
- Investigational
- Still being tested in clinical trials and not yet approved or legally sold for general use.
- Banned in drug-tested sport
- Prohibited by the World Anti-Doping Agency (WADA); using it can disqualify a competing athlete.
Sources
- Case report and literature review, melanotan II and kidney infarction(2020)Reviews documented complications including priapism, muscle breakdown, kidney damage, and melanoma.
- Melanotan review, Actas Dermo-Sifiliograficas
Last reviewed 22 July 2026