Melanotan II
Melanotan II · MT-2 · MT-II · MTII · Melanotan 2
Non-selective melanocortin agonist for deep tanning, with libido and nausea along for the ride.
Typical dose
250 mcg
Daily during the loading phase, then 1-2x weekly for maintenance
Range
100–1000
mcg
Half-life
—
see Dosing
Evidence
Early human
Subcutaneous · Intranasal
What it is
Melanotan II is a cyclic seven-amino-acid analogue of alpha-MSH, developed at the University of Arizona as a "sunless tanning" agent and never taken past small early-phase human work, including two placebo-controlled crossover trials in erectile dysfunction. It is the C-terminal amide; PT-141 is its deamidated metabolite, which is why MT-II produces the same sexual effects as a side effect of tanning.
It is non-selective across MC1R, MC3R, MC4R and MC5R. MC1R activation drives eumelanin production and the tan; MC4R activation drives the spontaneous erections, nausea and appetite suppression that come with it. You cannot separate them by dosing — they arrive together.
The tan is real and persistent, lasting weeks to months after the last injection, and it develops much faster with UV exposure than without. That is also where the risk sits. MT-II darkens existing moles, and case reports document eruptive new naevi, changes in existing lesions and melanomas diagnosed in users. Nobody using this compound should be skipping annual skin checks, and it does not remove the need for sunscreen — a deeper tan is not a substitute for UV protection.
How it works
MT-II binds melanocortin receptors with much higher potency and far greater metabolic stability than native alpha-MSH. At MC1R on melanocytes it raises cyclic AMP, shifting melanin synthesis toward eumelanin, so the skin tans darker and faster in response to the same UV dose.
The unwanted effects come from the same non-selectivity. MC4R agonism in the hypothalamus produces the erections, the flush of nausea in the first hour and the marked drop in appetite; MC3R and MC5R activity accounts for some of the flushing and sebaceous changes people report.
Dosing
Start at 100 mcg regardless of what you have read; the nausea at 500-1000 mcg on a first dose is genuinely unpleasant and tolerance builds within a week.
Reconstitution calculator
Pre-loaded with Melanotan II’s vial size, water volume and typical dose. Change anything.
Typical: 250 mcg · range 100–1000
Draw to
10 u
0.1 mL · 250 mcg
Concentration
2.5 mg/mL
25 mcg per unit
Doses per vial
20
Vial lasts
2 weeks 6 days
Draw to 10 units on the barrel.
Once mixed
Refrigerated at 2-8°C, use within about 4-6 weeks. Keep it dark and never freeze it once mixed.
2 mL into a 5 mg vial gives 2,500 mcg/mL, so 250 mcg is 10 units on a U-100 pin; the same 2 mL into a 10 mg vial gives 5,000 mcg/mL and 250 mcg becomes only 5 units — accurate but unforgiving. Using 5 mL in the 10 mg vial gives 2,000 mcg/mL and puts 250 mcg at a much easier 12.5 units. Run the water down the vial wall and swirl; do not shake.
Storage
Before mixing
Refrigerated at 2-8°C it keeps for years; sealed and dry it tolerates room temperature for a few weeks of shipping.
After mixing
Refrigerated at 2-8°C, use within about 4-6 weeks. Keep it dark and never freeze it once mixed.
Reported benefits
- ▪Produces a deep, long-lasting tan with far less UV exposure than tanning unaided
- ▪Tan persists for weeks to months after the last injection
- ▪Strong increase in libido and frequency of spontaneous erections
- ▪Marked appetite suppression, which some users run deliberately in a cut
- ▪Works in fair-skinned people who normally burn rather than tan
- ▪Cheap and widely available compared with the licensed melanocortin products
Side effects
- ▪Nausea and occasional vomiting, worst in the first hour and in the first week
- ▪Facial flushing and a warm, restless feeling after injection
- ▪Spontaneous and sometimes unwanted erections; priapism has been reported
- ▪Darkening of existing moles and freckles, plus eruptive new naevi
- ▪Appetite suppression and drowsiness or yawning
- ▪Uneven or patchy pigmentation, particularly on the face, hands and old scars
- ▪Isolated case reports of rhabdomyolysis and of melanoma diagnosed in users
Do not use if
- ▪Personal or family history of melanoma, or any atypical or dysplastic naevi
- ▪Large numbers of moles, or lesions you have not had a dermatologist look at
- ▪Known cardiovascular disease or uncontrolled hypertension
- ▪Pregnancy or breastfeeding
- ▪Immunosuppression, including transplant recipients on long-term therapy
Evidence level — Early human
Small or early-phase human studies only.
Not approved anywhere; sold as a research chemical, and several regulators including the MHRA and TGA have issued specific safety warnings against its sale for tanning.
Melanotan II FAQ
Do I still need sun exposure for it to work?+
Yes, in practice. MT-II primes melanocytes but UV is what triggers the actual pigment output, so people who dose without any sun or bed exposure see very little for weeks. Short, controlled exposures during loading are what produce the tan — a full session on day one still burns you.
Can I stop using sunscreen once I'm tanned?+
No. The added eumelanin gives you roughly a couple of SPF points at most, nowhere near enough to be protective, and you are stimulating melanocytes with an unlicensed compound while increasing UV exposure. The skin cancer risk goes up, not down.
How is this different from PT-141?+
PT-141 is the deamidated metabolite of MT-II. PT-141 is used as-needed purely for the sexual effect and rarely tans anyone; MT-II is dosed daily for the tan and delivers the sexual effect and the nausea whether you want them or not. Running both together just stacks the nausea and pigmentation.
Will the moles go back to normal when I stop?+
The general tan fades over weeks to months, but darkened moles and any new naevi that appeared often do not fully revert. Photograph your moles before you start and get a dermatologist to map them, because deciding whether a lesion has changed after the fact is otherwise guesswork.
Does the nausea ever stop?+
For most people it drops off sharply after the first three to five doses as tolerance builds. Dosing before bed, starting at 100 mcg, and taking an antihistamine or ondansetron 30 minutes before the shot are the standard ways through the first week.
References
- 1.Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study — Life Sciences (1996) PMID 8637402
- 2.Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study — The Journal of Urology (1998) PMID 9679884
- 3.Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction — Urology (2000) PMID 11018622
- 4.Eruptive melanocytic naevi following melanotan injection — The British Journal of Dermatology (2009) PMID 19575725
More sexual health & melanocortin
Melanotan I
Tanning-focused melanocortin agonist — the pigment of MT-II with far less nausea or erections.
500 mcg · Daily during the 10-14 day loading phase, then 1-2x weekly for maintenance
PT-141
Melanocortin agonist that works on desire in the brain rather than blood flow in the penis.
1 mg · As needed, no more than once in 24 hours and no more than 8 doses per month