Melanotan 2
MT-2
Melanotan 2 (MT-2) is the 'tanning peptide' — a synthetic α-MSH mimic that darkens skin without sun, which is why it's one of the most-searched research peptides. But it's also one of the most important to understand honestly, because its safety profile has real caveats. This guide covers how MT-2 works, what the research shows, its side effects and monitoring needs, dosing references and status.
Melanotan 2 quick facts
| Reported research dosing (Injectable) | 250mcg-1000mcg |
| Route | Subq |
| Cycle length | 4-12 Weeks (then maintenance) |
| Frequency | 1x Daily |
| Half-life | ~30-60 min |
| Forms | Injectable, Nasal |
| Evidence level | Anecdotal + animal |
| Other forms available | Nasal — dosed differently |
Tans and raises libido, but the nausea/appetite/mole changes are real. Start tiny.
How Melanotan 2 works
MT-2 is a synthetic cyclic 7-amino-acid peptide that mimics alpha-melanocyte-stimulating hormone (α-MSH) — but it's up to 1000× more potent and hits four melanocortin receptors (MC1R, MC3R, MC4R, MC5R). Tanning comes from MC1R: MT-2 drives a cAMP cascade that ramps up tyrosinase and shifts pigment toward eumelanin (the darker, more photoprotective type) — producing UV-independent tanning, darkening skin without sun exposure. Its activity at MC3R/MC4R also explains its secondary effects: appetite suppression and increased libido.
What the research shows
Human data is small. The most-cited study is a 1998 placebo-controlled crossover in 10 men that documented dose-dependent increases in skin melanin (measured by spectrophotometry) with visible tanning within days, plus — notably — erections in 8 of 10 participants (which is how the sexual-health peptide PT-141 was later derived from it). But there is no large randomized trial showing safe, effective tanning in healthy adults, and MT-2 has no approved clinical indication.
Safety & side effects — read this part
MT-2 is a compound where the risks deserve real attention. Common effects include nausea (especially early and at higher doses), flushing, and spontaneous erections in men. The bigger concern is dermatological: MC1R activation causes existing moles to darken and can prompt new moles (nevi) — which is why regular skin/dermatology monitoring is considered essential, and why there's ongoing concern about melanoma risk. This is not a casual cosmetic — it warrants genuine caution.
Melanotan 2 dosing (research reference)
Research references escalating subcutaneous doses (the 1998 study used roughly 0.01–0.025 mg/kg), typically with a lower 'loading' phase to build the tan and a smaller maintenance dose to hold it — started low specifically to limit nausea. It's a lyophilized powder reconstituted with bacteriostatic water; the calculator above converts a research amount into syringe units. This summarizes existing references for education only, not dosing advice or a recommendation for human use.
Related compounds
MT-2 is part of the melanocortin family. Its erection side-effect led directly to PT-141 (bremelanotide), which was developed to target sexual desire specifically. Melanotan 1 (afamelanotide) is a related, more MC1R-selective tanning peptide with a cleaner side-effect profile.
Legal & regulatory status
Melanotan 2 has no approved clinical indication and is not FDA-approved; it's sold as a research compound (research use only) and its sale for human use is restricted or banned in several countries. Given the melanoma-monitoring concerns, this is one to approach especially carefully. Follow the laws that apply to you.
Where to get Melanotan 2
Melanotan 2 is sold in 2 forms. They are not interchangeable — the dose and the route differ, so pick the one this page describes unless you know why you want another.
Melanotan 2 reconstitution calculator
Research reconstitution calculator
Bacteriostatic water is the diluent — sterile water with 0.9% benzyl alcohol, which is what lets a vial be drawn from more than once. It does not come with the vial, and unlike the compound it is bought again every time.
Need bacteriostatic water? Get it at AminoWell USA (my company) → Code CAMERON.
The evidence for Melanotan 2
Graded by what exists behind each claim.
✅ Clinically validated
- No randomized human trials — a research compound with no commercial route to funding one, so the correlative and theoretical tiers are the evidence base rather than a consolation prize.
- Afamelanotide — a closely related, more selective melanocortin analog — IS approved (Scenesse) for erythropoietic protoporphyria, which establishes that the receptor family can be safely targeted in humans. It does not validate the unselective version.
📊 Correlative data
- Heavy real-world use with a consistent and well-documented reported profile: nausea and facial flushing on early doses, spontaneous erections, appetite suppression, and reliable tanning with far less UV exposure.
- The case reports are the part worth reading. Published literature documents new and changing melanocytic naevi, and at least one melanoma diagnosed in a user. Causation is unproven; the biological plausibility is not in question.
🧪 Theoretical / extrapolated
- A non-selective melanocortin agonist — MC1R drives melanogenesis, MC3R/MC4R drive the libido and appetite effects. The lack of selectivity is why one compound produces such an unrelated-looking set of effects.
- The mechanism predicts the mole issue directly: stimulating melanocytes systemically is the point, and existing naevi contain melanocytes. That is the argument for a skin check before and during, and it comes from the pharmacology rather than from caution.
Why an empty tier is not a verdict →
How to read these tiers: they say how much human evidence exists, not how well something works — and ✗ flags harm, never a disappointing trial. How the evidence tiers work →
What Melanotan 2 actually does
Melanotan II is a cyclic melanocortin agonist built around the four-residue message sequence of alpha-melanocyte-stimulating hormone, His-Phe-Arg-Trp. Two deliberate changes turned a hormone fragment with a life measured in seconds into something that survives an injection: the phenylalanine at position 7 is the D-isomer rather than the natural L, which no mammalian peptidase is shaped to cut, and a lactam bridge between an aspartate and a lysine side chain locks the backbone into the beta-turn the receptor reads. The tan is downstream of a conformational lock, not of a bigger dose.
It is an agonist at four of the five melanocortin receptors, and that is the whole personality of the molecule. MC1R sits on melanocytes. MC3R and MC4R sit in the hypothalamus. MC5R sits on sebaceous and exocrine tissue. One compound, four receptors, four effects that look unrelated to each other and are not — a tan, appetite suppression, flushing and nausea, and the arousal effect are one pharmacology reported four different ways.
What MC1R actually does, step by step. It is a Gs-coupled receptor: agonist binding raises cyclic AMP, protein kinase A phosphorylates CREB, CREB drives transcription of MITF, and MITF is the master switch for tyrosinase and the two tyrosinase-related proteins. Tyrosinase is the rate-limiting enzyme of melanin synthesis. So the injection does not deliver pigment — it delivers a transcription signal, and the pigment is made afterwards by cells doing their own work.
And the pigment it makes is a particular pigment. Human melanocytes make two: eumelanin, which is brown-black and absorbs ultraviolet, and pheomelanin, which is red-yellow and generates reactive oxygen under ultraviolet rather than absorbing it. In seven volunteers with skin types III to IV given daily subcutaneous injections of the closely related linear analog for two weeks, biopsies showed forehead eumelanin up 49% and forearm eumelanin up 98%, with forearm pheomelanin unchanged from baseline Dorr 2000. That is the mechanistic claim in one sentence: melanocortin agonism shifts the ratio, it does not simply make more of everything.
The MC4R arm is the one nobody prices in. MC4R is the satiety receptor — the one whose loss-of-function variants are the commonest monogenic cause of human obesity. Agonize it and food intake falls. In two phase 1 randomized controlled trials of the MC4R-preferring cousin bremelanotide in women with a BMI over 30, total caloric intake fell by roughly 400 kcal per day and body weight by 1.3 kg against placebo in 16 days Spana 2022. The nausea and the appetite loss reported by every user are not side effects sitting beside the drug. They are the same receptor.
Cell, rodent, human — and where it stops
Step one, the receptor pharmacology, which is settled. The melanocortin-1 receptor's role in pigmentation, melanin synthesis, redox homeostasis and inflammation is not in dispute, and loss-of-function MC1R variants are known to suppress receptor coupling or surface expression and cut intracellular cyclic AMP Böhm 2024. Nothing on this page depends on the receptor being real.
Step two, in people — and this is where the page has to be careful, because the human data is about a different molecule. Seven volunteers, daily subcutaneous dosing for two weeks, punch biopsies before and after, eumelanin measured as its degradation product PTCA: the tanning was real and it was eumelanic Dorr 2000. A separate three-route comparison in humans measured the kinetics: the subcutaneous dose was completely bioavailable relative to intravenous, plasma half-lives were 0.07–0.79 h (absorption) and 0.8–1.7 h (beta phase), tanning of forehead, arms and neck followed intravenous or subcutaneous dosing, and oral dosing produced no detectable drug at all Ugwu 1997.
Both of those studies used melanotan-I, not melanotan-II. They are different peptides: one is a linear superpotent alpha-MSH analog that went on to become an approved medicine for erythropoietic protoporphyria, the other is the cyclic non-selective one on this page, which never entered a registration program. Quoting the first one's numbers for the second is the single commonest error made about this compound, and this page has just done it deliberately and said so, because there is nothing else to quote.
Step three, the controlled human evidence that IS about selective MC1R agonism, from an unexpected direction. A first-in-human study of dersimelagon, an oral selective MC1R agonist, dosed healthy participants across a 1 to 600 mg single-dose range and then multiple doses. The two commonest treatment-emergent adverse events after multiple dosing were lentigo in 52.8% and skin hyperpigmentation in 50.0%, and melanin density rose at 150 and 300 mg Ogasawara 2023. Read that against the case reports below: new pigmented lesions in half of participants is what a clean, selective, orally dosed MC1R agonist does in a controlled trial. It is the mechanism, not an accident of gray-market material.
The obstacles, named. (1) No randomized trial of melanotan-II exists in any indication. (2) No human pharmacokinetic study of melanotan-II has been published, so every half-life quoted for it is inferred from a different peptide. (3) There is no dose-response curve, so nobody can say whether the tanning dose and the systemic dose are the same dose. (4) The material is unregulated, which means preparation, administered dose and even identity are unverified — a review of the risks says exactly that, in those terms Habbema 2017.
Melanotan 2 pharmacokinetics — how much of it actually gets in
The card prints ~30–60 minutes. No published human pharmacokinetic study of melanotan-II supports that or any other number. What follows is what can honestly be reasoned, and where the reasoning runs out.
Oral is zero, and that is measured rather than assumed. In the human three-route study of the linear analog, oral dosing produced no detectable drug levels Ugwu 1997. The reason is structural: this is a peptide, and the stomach's pepsin, the pancreas's trypsin and chymotrypsin, and the brush-border aminopeptidases of the small intestine are all in the way before first-pass hepatic extraction even becomes relevant. The oral bioavailability of a heptapeptide is a rounding error, which is why every real route for this class is an injection.
What the modifications buy in plasma. Exopeptidases read free N- and C-termini and chymotrypsin-like enzymes cut after aromatic L-residues. The lactam bridge removes the linear termini and the D-phenylalanine at position 7 presents the wrong stereochemistry at the obvious cut site. Against the natural hormone, whose plasma life is seconds to a couple of minutes, that is a large multiplier — but a multiplier on an unmeasured baseline is not a half-life.
The number that actually matters is not a half-life at all. In the human tanning study, pigmentation persisted for three weeks after dosing stopped Ugwu 1997, while the drug itself was gone from plasma in hours. Those two facts are consistent, and the reason is the mechanism: the injection delivers a transcription signal, the melanocyte then spends days making pigment, and the pigment sits in keratinocytes until the epidermis turns over. Exposure is measured in hours and effect is measured in weeks, so dosing frequency chosen to ‘keep levels up’ is answering the wrong question. It is also the mechanism by which a loading schedule delivers far more receptor activation than the visible tan implies.
Nasal changes the risk without improving the arithmetic. A nasal spray of a peptide this size crosses the nasal mucosa poorly and deposits most of the dose on the mucosa itself. The one published consequence in a melanotan-II nasal-spray user is a mucosal malignant melanoma of the anterior maxilla in a 22-year-old Yassin Alsabbagh 2025.
What would have to be true, and how you would know it was not
Three predictions. The first two are cheap blood draws nobody has run; the third is the one that argues against the product.
1. Cortisol and ACTH should not move — and if they do, this is not the drug it is described as. There are five melanocortin receptors and MC2R is the odd one out: it is the ACTH receptor on the adrenal cortex, and it is the one this peptide is not supposed to reach. That is a testable claim. Draw an 8 a.m. cortisol and ACTH at baseline and again at 6 weeks on a stable schedule. Prediction: both flat. If cortisol climbs, the selectivity assumption everyone is relying on is wrong, and the compound in the vial is doing something the pharmacology does not describe. Nobody has ever published this pairing for melanotan-II.
2. Fasting insulin and body weight should fall at a tanning dose, and that is a test of whether the MC4R arm is engaged at all. The MC4R-preferring analog cut intake by about 400 kcal per day and produced measurable weight loss inside 16 days Spana 2022. So: weigh daily under fixed conditions and draw fasting insulin at baseline and 8 weeks. If weight and fasting insulin are genuinely flat at a dose that visibly tans, then MC1R is being engaged at a concentration MC4R is not — which would be the most useful piece of dosing information anyone has produced about this compound, and would also predict no arousal effect at that dose. If they fall, the systemic arm is engaged and the nausea is not optional.
3. The prediction that cuts against it: new pigmented lesions should appear, in a substantial minority, and this is not rare. A selective MC1R agonist in a controlled trial produced lentigo in 52.8% of participants after multiple doses Ogasawara 2023. Prediction: dermoscopic photographs of every nevus at baseline and at 12 weeks will show measurable change in a large fraction of users, not a handful. There is no blood marker for this — the instrument is a camera and a mapped baseline, and without the baseline a changed mole is undetectable. The mechanism predicts it; a page that only predicted the tan would be advertising.
What nobody has tested yet
Four experiments that have never been run and could be, listed because the people running them on themselves may as well collect a number.
Nobody has published a single human pharmacokinetic curve for melanotan-II. Not one. Everything quoted for it — including the half-life on the card above — is borrowed from melanotan-I Ugwu 1997. Eight timed plasma samples after one subcutaneous dose, in one person, would be more information about this molecule's kinetics than currently exists anywhere.
Nobody has measured the eumelanin-to-pheomelanin ratio in a melanotan-II user. The assay exists and has been run for the other peptide on punch biopsies Dorr 2000. Whether the non-selective cyclic version produces the same photoprotective ratio shift, or simply more pigment of both kinds, is the difference between a plausible photoprotection argument and none, and it has never been checked.
Whether the tanning dose and the systemic dose are separable. If MC1R saturates at a lower concentration than MC4R, there is a dose that tans without nausea, appetite loss or arousal effects. That is an ordinary dose-ranging question, it is answerable with a stepped protocol and a reflectance meter, and no public dataset addresses it.
Whether people with many nevi respond differently from people with few. The published case material describes change in existing moles rather than only new ones Habbema 2017. If nevus count predicts who develops pigmented change, that is a before-you-start screening variable with a real basis. Nobody has stratified anything by it.
Melanotan 2 — its own safety story, not its class's
This compound's risk story is dermatologic and vascular, and both halves are mechanism-linked rather than idiosyncratic. Nothing in the class block below about injection technique is the point here.
The moles. Read the review rather than the forum. A dermatology review of unregulated alpha-MSH analog use reports increasing numbers of case reports of melanocytic changes in existing moles and newly emerging dysplastic nevi, and four case reports describing melanomas emerging from existing moles either during or shortly after use. It also says plainly that conclusive evidence linking the two is lacking, and that multiple national health organizations have issued safety warnings Habbema 2017. Both halves of that are the honest position: the association is unproven and the biological plausibility is not in question.
And the counter-argument, which is real and is also not a defense. Chronic MC1R activation increases pigmentation and DNA repair and controls aberrant cell growth, and may reduce melanoma risk — but the same review states that it importantly does not prevent melanoma, particularly in people with risk factors, and that regular skin examination remains critical Böhm 2024. A tan produced pharmacologically is still a tan produced by a mechanism that does not make you safe, and the reduced sunburn signal removes the feedback that normally limits exposure.
Priapism is a surgical emergency and it has happened here. A published case describes acute ischemic priapism after subcutaneous melanotan-II which failed cavernosal aspiration, irrigation and intracavernous phenylephrine and required operative penoscrotal decompression; it was the third such case in the literature at the time Mallory 2021. Ischemic priapism is time-limited tissue survival, not an inconvenience, and the relevant number is hours.
The supply problem is specific rather than generic. This is sold as an unlicensed tanning product, so preparation, administration and dose are all unverified Habbema 2017, and there is no assay available to a buyer that distinguishes the cyclic lactam from a linear impurity with a different receptor profile. The single measure with a mechanistic basis is a mapped, photographed baseline of the whole skin before anything is injected — because the documented effect is change, and change is invisible without a starting picture.
Sources read for this page
- Böhm M, et al. An overview of benefits and risks of chronic melanocortin-1 receptor activation. Journal of the European Academy of Dermatology and Venereology 2024 · PMID 39082868
- Habbema L, Halk AB, Neumann M, Bergman W. Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review. International Journal of Dermatology 2017 · PMID 28266027
- Mallory CW, Lopategui DM, Cordon BH. Melanotan Tanning Injection: A Rare Cause of Priapism. Sexual Medicine 2021 · PMID 33460908
- Yassin Alsabbagh A, et al. Melanotan II nasal spray: a possible risk factor for oral mucosal malignant melanoma?. International Journal of Oral and Maxillofacial Surgery 2025 · PMID 40210573
- Ogasawara A, et al. Results from a first-in-human study of dersimelagon, an investigational oral selective MC1R agonist. European Journal of Clinical Pharmacology 2023 · PMID 37060458
- Spana C, Jordan R, Fischkoff S. Effect of bremelanotide on body weight of obese women: Data from two phase 1 randomized controlled trials. Diabetes, Obesity and Metabolism 2022 · PMID 35170192
- Dorr RT, Dvorakova K, Brooks C, Lines R, Levine N, Schram K, Miketova P, Hruby V, Alberts DS. Increased eumelanin expression and tanning is induced by a superpotent melanotropin [Nle4-D-Phe7]-alpha-MSH in humans.. Photochem Photobiol 2000 · PMID 11045725
- Ugwu SO, Blanchard J, Dorr RT, Levine N, Brooks C, Hadley ME, Aickin M, Hruby VJ. Skin pigmentation and pharmacokinetics of melanotan-I in humans.. Biopharm Drug Dispos 1997 · PMID 9113347
Melanotan 2 — safety, predicted from mechanism
Predicted from mechanism, not from a human safety trial. How that reasoning works →
What the mechanism predicts
Derived from the molecule, not a trial.
- These are melanocortin receptor agonists and they are not selective, which is the whole safety story. MC1R gives the tanning. MC4R gives the nausea, the flushing and the erections. You do not get to choose which receptors respond.
- The mole question is the one that matters. These drive melanogenesis systemically — existing naevi commonly darken and new ones can appear. That is not itself cancer, but it makes melanoma surveillance harder precisely in people using a tanning agent.
What has actually been reported
- Nausea in the first hours after dosing is very common and usually settles with repeated exposure. Facial flushing, spontaneous erections and appetite suppression are all frequently reported.
- Case reports exist of melanoma diagnosed in Melanotan users. Causation is not established and the population self-selects for sun exposure — but 'unproven' is not 'reassuring' here.
How to reduce the risk
Same mechanism as the prediction.
- Get a full-body skin check before you start, and photograph your moles. This is the whole mitigation. The predicted problem is that melanogenesis makes surveillance harder — a dated set of baseline photographs is what makes 'has this changed?' answerable later.
- Start at a fraction of the intended dose. The nausea and flushing are MC4R effects that attenuate with exposure, so almost everyone who has a miserable first experience simply started too high.
- Dose in the evening. If the nausea lands, you sleep through the worst of it.
- Sun protection does not become optional because you tan faster. Melanin is partial protection, and the tan is not the part that matters here — the mole surveillance is.
- Any new lesion, or an existing one that changes shape, color or border, is a dermatologist appointment rather than a forum question.
What it does to your bloodwork
A fact about the assay.
- No routine marker tracks this. The monitoring here is dermatological, not hematological — get a skin check and photograph your moles before you start.
Don't run this if
- Personal or family history of melanoma, or many atypical moles.
- Any pigmented lesion you have not had looked at.
The honest unknown
- Whether driving melanogenesis for years changes melanoma risk in humans. Nobody has run that study and it is not obvious anyone will.
Not medical advice. If you take prescription medication or have a diagnosed condition, check this with a pharmacist or doctor.
Food is not a factor — pick a time you will keep
Nothing you eat touches a subcutaneous injection, so there is no meal to plan around. What does matter is a fixed slot: the commonest reason an injectable protocol underperforms is missed doses, not mistimed ones.
With a short half-life, dose it near the effect you want rather than at a fixed hour.
From half-life and route, not a dosing trial.
Melanotan 2 — interference & stacking
Predicted from mechanism, not from an interaction study. How mechanism-predicted claims are made →
What Melanotan 2 moves on your bloodwork
Expected direction, not a measured one.
- Comprehensive Metabolic Panel (CMP) — ◆ worth watching
Blood pressure is the thing to watch here and it is not a lab — melanocortin agonists can raise it transiently after dosing.
What to do: Take blood pressure before and an hour after a dose the first few times. That tells you more than any panel.
The mechanism-predicted concern that matters is not on a blood panel: melanocortin agonists stimulate melanocytes, so existing moles darkening or changing is the signal to take seriously, and a skin check before starting is the version of a baseline that applies here.
Everything on this page, in an order
This one is free and stays free. What Skool adds is the rest of the shelf — 278 compounds and 371 supplements with the protocol, the stack order and the bloodwork to run beside it.
Join Skool — $10/mo →Bloodwork to run alongside Melanotan 2
Baseline first, then again at 8–12 weeks.
| Marker | What it’s watching for |
|---|---|
| Complete Blood Count (CBC) with Differential | General baseline — but bloodwork is not the monitoring that matters here |
Check results you already have → · All 103 markers A–Z
Melanotan 2 — frequently asked questions
What is Melanotan 2?
Melanotan 2 (MT-2) is a synthetic α-MSH-mimicking peptide that darkens skin without sun by activating melanocortin receptors. It's researched as a 'tanning peptide' and also causes appetite suppression and increased libido.
How does Melanotan 2 make you tan?
It activates MC1R, driving a cAMP cascade that boosts tyrosinase and shifts pigment toward eumelanin — producing UV-independent tanning (darkening without sun exposure).
Is Melanotan 2 safe?
It has real caveats. Common effects are nausea, flushing and spontaneous erections; more importantly, it darkens existing moles and can prompt new ones, so dermatology monitoring is considered essential and melanoma risk is a genuine concern. There's no large safety trial in healthy adults.
How is Melanotan 2 dosed?
Research references escalating subcutaneous doses (the key study used ~0.01–0.025 mg/kg), usually a low loading phase then a maintenance dose, started low to limit nausea. Reconstituted with bacteriostatic water (see calculator). Educational only, not dosing advice.
What's the difference between Melanotan 2 and PT-141?
PT-141 (bremelanotide) was derived from Melanotan 2's erection side effect and engineered to target sexual desire specifically. MT-2 is primarily a tanning peptide; PT-141 is a sexual-health peptide.
Is Melanotan 2 FDA-approved?
No. It has no approved clinical indication, is not FDA-approved, and its sale for human use is restricted or banned in several countries. It's sold as a research compound.
References & further reading
- Melanotan II: mechanism, effects & research studies (Peptpedia)
- Melanotan II: mechanism, evidence, risks and alternatives (PeakedLabs)
What Melanotan 2 is used for
Melanotan 2 appears under 2 goals in the goal router.
Related Hormonal & Sexual compounds
Where this goes next
The pages here are the frameworks. The protocols — the dosing, the order to correct things in, the week-by-week schedule and what to retest — are inside Skool.