Human studiesMelanocortin agonist (tanning)

Melanotan 2

Melanotan II, MT-II

Common dose: 250–500 mcg daily, then weekly
Cycle: Load 4 weeks, then maintain
Vial sizes: 10 mg
Typical draw: 5 units10 mg with 2 mL, 250 mcg

A cyclic alpha-MSH analog that activates several melanocortin receptors, causing tanning along with appetite suppression and sexual arousal.

Evidence. Only three small trials (3 to 10 men each), published 1996 to 2000. Two tested erections in men with erectile dysfunction; only the 3-man pilot measured tanning. Never approved, and linked to serious adverse-event case reports.

Status

Approval: Not approved as a drug in the US or EU.
US compounding: Nomination withdrawn, so Melanotan II is no longer in FDA Category 2 (April 2026). Not on the July 2026 advisory committee agenda.
Sport (WADA 2026): Likely banned in sportNot named on WADA’s 2026 list, but its S0 rule bans drugs with no current human approval anywhere, at all times.

Category 2 is FDA’s list of bulk substances that may present significant safety risks in compounding. The 503A bulks list adds substances that pharmacies may compound with. Advisory committee votes are advice; FDA makes the final decision. Sport status follows the WADA Prohibited List in force since January 1, 2026; athletes should confirm with their anti-doping organization. Checked October 5, 2026. Status of every compound.

How it works

TrialMainly from studies in people.

Not known

Whether it raises melanoma risk is unknown: there are case reports but no controlled data. Effects of repeated use over months, and what unregulated vials actually contain, are also unknown.

Protocol

Community

Test dose of 100–250 mcg, then 250–500 mcg daily until the desired tone, then 500–1,000 mcg 1–2× per week.

Frequency: Daily while loading, then 1–2× per week
Route: Subcutaneous injection
Timing: Bedtime, so nausea peaks during sleep.
Cycle: Loading for about 2–6 weeks, then maintenance. No established cycle.
Load 4 weeks, then maintain, shown over 26 weeks

Common protocols

The ways Melanotan 2 is most often run, each tagged with where it comes from.

Community loading

Community

Dose: Test 100–250 mcg, then 250–500 mcg
How often: Daily
How long: About 2–6 weeks, until desired tone

Unapproved. Starting low is meant to gauge nausea and flushing.

Community maintenance

Community

Dose: 500–1,000 mcg
How often: 1–2× per week
How long: No established limit

Unapproved. No data on long-term safety.

Draw 10–20 units10 mg + 2 mL

1996 pilot trial

Trial

Dose: 0.01–0.03 mg/kg
How often: Every other day (placebo on the days between)
How long: 2 weeks

Dorr 1996, 3 men. About 0.7–2.1 mg at 70 kg, higher than typical community doses. 0.025 mg/kg was suggested for later studies.

Dosing by body weight

Trial

0.01–0.03 mg/kg. Dorr 1996 pilot, 3 men, subcutaneous; 0.025 mg/kg/day suggested for later studies

Body weight

At 70 kg, per dose700 mcg–2.1 mg14–42 units at 10 mg + 2 mL

Community loading pattern

Period	Dose	Draw at 5 mg/mL
Days 1–3 (test dose)	100 mcg	2 units (0.02 mL)
Loading (daily)	250 mcg	5 units (0.05 mL)
Maintenance (1–2× per week)	500 mcg	10 units (0.10 mL)

Units assume a 10 mg vial mixed with 2 mL. Use the calculator for other vial sizes.

Taking it

Where it goes

Subcutaneous injection (under the skin), rotating sites. Vials are unlicensed, so sterility and actual dose can’t be trusted.

If you miss a dose

No published guidance; it isn’t an approved drug. Don’t double up; resume the usual schedule.

What to expect

1–5 hours after a dose
Yawning and stretching, then spontaneous erections in men. Mild nausea at most doses in the pilot trial.
Trial
After about 5 doses
In the 1996 pilot, 2 of 3 men had darker skin on the face, upper body and buttocks.
Trial

Side effects and what to do

Nausea, flushing, reduced appetite

Common early on. Guides start low and dose at bedtime. Stop if vomiting persists.

Spontaneous erections; priapism in case reports

An erection lasting more than 4 hours is an emergency.

New, darker or atypical moles; melanoma case reports

Stop and have any new or changing mole checked by a dermatologist.

Rhabdomyolysis (muscle breakdown) and encephalopathy in case reports

Severe muscle pain, dark urine, bad headache or confusion needs emergency care.

Infection or contamination from unlicensed vials

Products are unregulated. A hot, red, swollen or pus-filled site needs medical care.

Stop and get medical help

A mole that changes, bleeds or itches; an erection over 4 hours; severe muscle pain or dark urine; severe headache, confusion or vision changes; an infected injection site.

Who should avoid it

No product label covers Melanotan 2, so these come from human studies and from precautions based on how it works. Most important first.

Past melanoma or atypical moles: PrecautionIt darkens moles and can bring out new ones within days, and case reports describe melanomas in users. No study has tested whether it causes cancer.
Uncontrolled high blood pressure or heart disease: PrecautionBremelanotide, a near-identical approved drug, briefly raises blood pressure and its label rules it out with these conditions; an overdose case report described a racing heart and raised blood pressure.
Pregnancy or breastfeeding: PrecautionNo human safety data exist. Bremelanotide, a near-identical drug, raised pregnancy loss in dogs, its label says.
Men with a history of priapism: PrecautionSpontaneous erections are common, and case reports describe priapism, an erection lasting hours that needs emergency care.
Anyone relying on product quality: PrecautionIt isn’t an approved drug, so vials have no regulated standard for identity, purity or sterility. FDA flags possible immune reactions from impurities.

Interactions

No interaction studies have been published, and no product label lists any. The label for bremelanotide, a near-identical approved drug, warns that it sharply lowers oral naltrexone levels and may slow absorption of other oral drugs.

Precaution: follows from how it works or from a related drug, and hasn’t been tested. This isn’t a complete list: a pharmacist or doctor can check a specific medicine or condition.

Tracking and pairing

Worth tracking

New or changing moles
Erections lasting over 4 hours
Muscle pain or dark urine

Often paired with

Usually run on its own.

Human studies

3 key published human studies, with how many people took part. Animal studies aren’t listed here.

199810 people

Erections in 8 of 10 men with psychogenic ED; rigid erection time 38.0 vs 3.0 minutes with placebo (p=0.0045); more nausea and yawning.

Design
Double-blind placebo-controlled crossover
Dose
0.025 mg/kg subcutaneous
Length
Single doses, 6-hour monitoring

Wessells et al., J Urol 1998, PMID 9679884
200010 people

Erections after 12 of 19 injections vs 1 of 21 placebo doses in men with organic ED; severe nausea after 4 of 19 injections.

Design
Double-blind placebo-controlled crossover
Dose
0.025 mg/kg subcutaneous, two doses each of drug and placebo
Length
Single doses, 6-hour monitoring

Wessells et al., Urology 2000, PMID 11018622
19963 people

Visible tanning in 2 of 3 men after 5 low doses; mild nausea, somnolence at 0.03 mg/kg, and spontaneous erections.

Design
Single-blind placebo-controlled pilot (phase 1)
Dose
0.01–0.03 mg/kg subcutaneous, weekdays on alternate days
Length
2 weeks

Dorr et al., Life Sci 1996, PMID 8637402

All human studies on Vial Guide

Limits of the evidence

Melanotan 2’s human record is three tiny trials from 1996–2000 with 23 men in total: two erection studies using single doses and a 2-week tanning pilot in 3 men. Most of what else is known comes from case reports of harm, including melanoma, priapism, muscle breakdown and brain swelling. The repeated injections people use, long-term safety and what vials contain have never been tested.

Mixing your vial

Vial	Water	Common dose	Draw	Strength	Action
10 mg	2 mL	250 mcg	5 units (0.05 mL)	5 mg/mL

Dose chart

10 mg vial

Syringe units for common doses at different water volumes. Select a cell to open it in the calculator.

Dose	Water added
Dose	1 mL	2 mL	3 mL
100 mcg
250 mcg
500 mcg
1,000 mcg

U-100 insulin syringe: 100 units is 1 mL. Draws over 100 units show in mL. Faded values are under 2 units, which is hard to measure. Check that your vial holds the larger volumes.

Datasheet

Half-life: No reliable value has been published.
Type: Peptide, 7 amino acids
Molecular weight: 1,024.2 g/mol
Formula: C₅₀H₆₉N₁₅O₉
Sequence: Ac-[Nle]-cyclo(DH[D-Phe]RWK)-NH2
Storage before use: Freezer (about −20 °C) for long-term storage, kept dry and away from light.
After mixing or opening: Fridge (2–8 °C); use within about 4 weeks.

Molecule: PubChem CID 92432 (melanotan II)
Storage: Community Common research-peptide practice; no manufacturer stability data found.

Every compound side by side: the half-life chart and the storage chart.

Cautions

New or darkening moles within days; melanoma case reports.
Priapism and rhabdomyolysis have been reported.
Nausea, flushing and spontaneous erections are common.

Questions

What is Melanotan 2?

A cyclic alpha-MSH analog that activates several melanocortin receptors, causing tanning along with appetite suppression and sexual arousal.

How does Melanotan 2 work?

Melanotan 2, a ring-shaped copy of part of the tanning hormone alpha-MSH, binds strongly in lab tests to several melanocortin receptors, the family alpha-MSH acts on. These include MC1 on pigment cells, and MC3 and MC4, which in the brain affect appetite and sexual function. Small human trials saw tanning, erections, nausea and yawning. It differs from the approved drug bremelanotide (Vyleesi) only at one end of the chain. Whether it raises melanoma risk is unknown: there are case reports but no controlled data. Effects of repeated use over months, and what unregulated vials actually contain, are also unknown.

Is Melanotan 2 FDA-approved?

Not approved as a drug in the US or EU. Nomination withdrawn, so Melanotan II is no longer in FDA Category 2 (April 2026). Not on the July 2026 advisory committee agenda.

What is the usual Melanotan 2 dose?

From community reports, not established: Test dose of 100–250 mcg, then 250–500 mcg daily until the desired tone, then 500–1,000 mcg 1–2× per week. These are the amounts sources reference, not recommendations.

How much water do I mix Melanotan 2 with?

There’s no single right amount, because the water only sets the strength. With 2 mL of bacteriostatic water in a 10 mg vial, the strength is 5 mg/mL, so 250 mcg is 5 units on a U-100 insulin syringe. More water makes small doses easier to measure. The dose chart above shows other volumes.

Who should avoid Melanotan 2?

No product label covers Melanotan 2, so these come from human studies and from precautions based on how it works. Past melanoma or atypical moles: It darkens moles and can bring out new ones within days, and case reports describe melanomas in users. No study has tested whether it causes cancer. Uncontrolled high blood pressure or heart disease: Bremelanotide, a near-identical approved drug, briefly raises blood pressure and its label rules it out with these conditions; an overdose case report described a racing heart and raised blood pressure. Pregnancy or breastfeeding: No human safety data exist. Bremelanotide, a near-identical drug, raised pregnancy loss in dogs, its label says. The “Who should avoid it” section lists 2 more groups.

How should Melanotan 2 be stored?

Before mixing: Freezer (about −20 °C) for long-term storage, kept dry and away from light. After mixing: Fridge (2–8 °C); use within about 4 weeks. This is common practice; no product label covers it.

Is Melanotan 2 banned in sport?

Probably. Not named on WADA’s 2026 list, but its S0 rule bans drugs with no current human approval anywhere, at all times.

Has Melanotan 2 been studied in people?

Yes. The human studies section lists 3 published studies. The largest, from 1998, included 10 people. Erections in 8 of 10 men with psychogenic ED; rigid erection time 38.0 vs 3.0 minutes with placebo (p=0.0045); more nausea and yawning.

Sources

Melanotan II overdose associated with priapism (Clin Toxicol) doi:10.3109/15563650.2013.784775
Nelson et al., melanotan II injection resulting in systemic toxicity and rhabdomyolysis (Clin Toxicol 2012) PMID 23121206

For the protocol details

Dorr et al., melanotan-II pilot phase I study (Life Sci 1996) PMID 8637402
Habbema et al., risks of unregulated use of alpha-MSH analogs such as melanotan II, review (Int J Dermatol 2017) PMID 28266027

For how it works, who should avoid it and the limits of the evidence

Schiöth et al., MTII binding to human melanocortin receptors (Peptides 1997) PMID 9357059
Hjuler & Lorentzen, melanoma after melanotan II use, case report (Dermatology 2014) PMID 24355990
Vyleesi (bremelanotide) prescribing information, sections 4, 5, 7 and 8 (DailyMed, Nov 2025)
FDA, bulk drug substances that may present significant safety risks: Melanotan II (Apr 2026)

Doses tagged Community come from public dosing guides and user reports, checked against at least two of them. Those sites aren’t named here because many of them sell peptides or earn commissions on them.

By Vial Guide editorsLast reviewed October 5, 2026

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