Melanotan II
A powerful but unapproved tanning peptide — with real safety warnings from regulators.
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
Skin darkening
Darkened skin in small early human studies, even with little sun.
Erections / arousal
Triggered erections in small pilot studies in men; this led to the development of PT-141.
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.
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.
- 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.
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).
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
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.
Regulations change often — verify with the FDA, EMA, MHRA, Health Canada, TGA and WADA before acting.
Where to buy
Melanotan II vials
| Size | Price | Per mg | Stock | Latest COA |
|---|---|---|---|---|
| 10 mg | $29.95 | $3.00 | In stock | 99.83% pure, lot MII0002 ILS Labs, tested 2026-07-30 |
Melanotan II nasal spray (ready-made)
View ↗| Size | Price | Per mg | Stock | Latest COA |
|---|---|---|---|---|
| 15 mg | $59.99 | $4.00 | In stock | 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.
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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.