Melanotan II

A powerful but unapproved tanning peptide — with real safety warnings from regulators.

Not FDA-approved; FDA has acted against sellersEvidence

Overview

Melanotan II is a short, cyclic version of α-MSH developed in the 1990s. It darkens skin strongly and also affects appetite and sexual arousal — PT-141 (bremelanotide) was developed from it. It was never approved anywhere, and regulators in the US, UK and Australia have warned the public about unlicensed tanning injections and nasal sprays.

How it works

A non-selective melanocortin receptor agonist. MC1R activation drives tanning; MC3R/MC4R activation in the brain affects appetite and sexual function. That lack of selectivity is why side effects are common.

Evidence

3/5

Small, older human pilot studies (tanning; erectile function) plus a long list of case reports of harms. No modern trials and no approval.

Half-life

Roughly 1 hour or less (short); tan builds over repeated doses

Known as

MT-II, MT2, 'Barbie drug'

Compound facts

CAS Number: 121062-08-6
Molecular Formula: C50H69N15O9
Molecular Weight: 1024.18 g/mol
Sequence: Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
Structure: Cyclic lactam

Reported benefits

Human data

Skin darkening

Darkened skin in small early human studies, even with little sun.

Human data

Erections / arousal

Triggered erections in small pilot studies in men; this led to the development of PT-141.

Anecdotal

Appetite suppression

Commonly reported by users.

“Anecdotal” means reported by users, not shown in controlled trials.

Community-reported regimens

Not recommendations. These are commonly cited ranges, shown so you can see what real-world use looks like.

Plan	Dose	Frequency	Duration	Route
Community (test dose) Users commonly start this low to gauge nausea and flushing.	100 mcg	Once	First dose only	Subcutaneous
Community (loading) Range 250–500 mcg cited. Higher doses mainly add side effects.	250 mcg	Once daily or every other day	1–3 weeks until desired color	Subcutaneous
Community (maintenance)	250 mcg	1–2× per week	As needed	Subcutaneous

Reconstitution calculator

Set up for Melanotan II. Switch peptide or vial size any time.

Peptide

Vial

Walk me through it

1Mix

Add 2 mL water for 5 mg/mL

2Draw

Draw to 5 units = 0.05 mL = 250 mcg

Drag the plunger to set your dose.

3Inject

Next site

Right belly, upper

Tap a site after you inject to keep a rotation.

Pinch the skin, stay 2 in. from the navel, then into a sharps bin.

Peptide in vial (mg)

Water to add (mL)

Dose

Doses per day

Days per week

Community doses:

Doses per vial: 40
Vial lasts: 40 days
Good once mixed: ~28 days
Syringe: 30-unit, 0.3 mL

The vial outlasts its ~28-day shelf life once mixed. A smaller vial wastes less.

Easier numbers, add this much water:

Math only: concentration (mg/mL) = vial mg ÷ mL of water; units = dose (mg) ÷ concentration × 100. Always double-check against your own vial label and a clinician. This tool does not recommend a dose.

Reconstitution

Diluent: Bacteriostatic water (0.9% benzyl alcohol) — allows multiple draws from one vial.

Wipe both vial tops with an alcohol swab and let dry.
Draw the diluent, then inject it slowly down the inside wall of the vial — never straight onto the powder.
Swirl gently or let it sit; do not shake. Foam can damage peptides.
Solution should be clear. Cloudy, stringy or discolored = discard.
Common mix: 10 mg + 4 mL = 2.5 mg/mL (250 mcg = 10 units).

Full reconstitution guide →

Storage

Powder

Freezer / fridge

Keep sealed vial in the freezer (−20 °C) for long-term storage; fridge (2–8 °C) is fine for a few weeks. Keep dry and out of light.

After mixing

~28 days

Refrigerate at 2–8 °C. Never freeze after mixing. Keep upright, capped, and out of light.

Travel

Keep cool

Short trips at room temperature are generally fine for powder; keep mixed vials cold.

Light-sensitive — keep the vial in its box.
A ready-made nasal spray version is also sold; nasal absorption is less predictable than injection.

Side effects & cautions

Reported side effects

Nausea and vomiting (very common, especially early)
Facial flushing
Spontaneous erections; priapism (prolonged painful erection) has been reported
Loss of appetite, yawning, fatigue
New moles, darkening or changing moles, freckling
Rare serious reports: melanoma, muscle breakdown (rhabdomyolysis), kidney problems

Cautions

Case reports link MT-II use to new or changing moles and melanoma. It can also hide warning signs of skin cancer. Avoid if you have many moles, a history of melanoma, or a family history of skin cancer, and get regular skin checks.
An erection lasting more than 4 hours is a medical emergency.
Regulators have warned against it: the FDA issued a warning letter to a seller in 2007, the UK MHRA warned the public in 2008 after receiving reports of suspected side effects, and Australia's TGA has warned consumers and fined suppliers.
Products are unregulated — contamination, wrong dose and shared-needle infection risks are real.
Raises blood pressure and heart rate in some people; avoid with heart disease.
Do not combine with PT-141 — they act on the same receptors.

FDA & international status

FDA

Not FDA-approved; FDA has acted against sellers

Melanotan II has never been approved by the FDA or any other regulator. In 2007 the FDA issued a warning letter to a US distributor for illegally marketing it as a tanning agent and skin-cancer preventive. Its derivative PT-141 (bremelanotide, Vyleesi) is approved, but that is a different compound. Melanotan II was in FDA compounding Category 2 until April 2026, when its nomination was withdrawn; an FDA advisory committee is due to review it by February 2027.

European UnionNot authorized; national regulators treat it as an unlicensed medicine.

United KingdomUnlicensed; MHRA has warned against use and shut down websites selling it.

CanadaNot authorized for sale.

AustraliaPrescription-only medicine with no approved products; TGA warns consumers and has fined unlawful suppliers.

WADANot specifically named; as a substance with no regulatory approval it may fall under the S0 'non-approved substances' category.

Regulations change often — verify with the FDA, EMA, MHRA, Health Canada, TGA and WADA before acting.

Where to buy

Melanotan II vials

Shop this product ↗

Size	Price	Per mg	Stock	Latest COA
10 mg	$29.95	$3.00	In stockBuy ↗	99.83% pure, lot MII0002 ILS Labs, tested 2026-07-30

Past COAs (2 lab reports)

2026-07-30, 10 mg, lot MII0002, 99.83% pure, measured 10.48mgILS Labs, passedView PDF
2026-05-29, 10 mg, lot MII0001, 99.58% pure, measured 10.65mgILS Labs, passedView PDF

Melanotan II nasal spray (ready-made)

Shop this product ↗

Size	Price	Per mg	Stock	Latest COA
15 mg	$59.99	$4.00	In stockBuy ↗	Passed, lot SMII0001 Ethos Analytical, tested 2026-08-20

Amino Club list prices as of 2026-10-07, before promo codes. Multi-buy: 2+ units 5% off, 3+ units 7.5% off, 10+ units 40% off. Prices change; confirm on the product page. Mixing? Their bacteriostatic water is Amino H2O from $19.99.

Melanotan II at Amino Club

Check sizes, current price and the certificate of analysis (COA) on the product page. Sold for in-vitro research only.

Shop Melanotan II ↗

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Look for a batch-specific COA with HPLC purity (≥98%) and mass-spec identity.
Typical vial sizes: 10 mg.

FAQ

Is the nasal spray safer than injecting?

It avoids needles, but the drug and its risks are the same. Spray dosing is also less precise.

Why does it cause nausea and erections?

It isn't selective — besides the tanning receptor, it activates brain receptors that control appetite and sexual arousal.

Does a Melanotan tan protect against sunburn?

Darker skin gives some extra protection, but MT-II also raises mole and melanoma concerns. It is not a substitute for sunscreen.

Read the primary research on PubMed ↗