Melanotan II
Skin & anti-agingSexual healthAlso known as: MT-II, MT2, Melanotan 2
A melanocortin agonist injected to darken skin and, at higher doses, to raise libido. Not approved, and it carries real skin risks.
2.What it is / mechanism
Melanotan II is a synthetic copy of alpha-MSH that switches on melanocortin receptors. Through the MC1 receptor it makes skin produce more melanin, which darkens it with less sun. Through MC3 and MC4 receptors in the brain it can raise sexual desire and cause erections. That same broad receptor activity is why it commonly causes nausea, flushing, and appetite loss.s1
3.What the evidence supports
- Limited human dataDarkens skin with less sun exposure.s1
It clearly works, mostly documented through user reports and small studies. It is not a safe or approved tanning method.
- Anecdotal onlyRaises libido and causes erections.
Reported by users. Its relative PT-141 is the studied and approved option for sexual desire.
4.Dosing
| Route(s) | subcutaneous |
|---|---|
| Typical range | For tanning, often about 200 mcg daily for a week, then 100 mcg twice weekly once color builds. For libido, higher doses around 0.5 to 2 mg are used, which bring more side effects. |
| Frequency | Daily during loading, then a couple of times a week |
| Cycle guidance | Cycled, for example 4 to 8 weeks on with breaks. A lower total dose means fewer side effects. |
| Notes | Not approved, and the dosing is entirely community derived. Start very low, since nausea and flushing are common. This does not protect against sunburn or skin cancer. A darker tan is not a safe substitute for sun protection. |
A dose is only as good as the draw. Which syringe you need depends on how much water you mixed with, and the most common gear mistakes (a 0.5 mL syringe that cannot hold the dose, a mixing barrel that ships without needles, sizing up a needle because of body fat) are all avoidable. See what to buy: syringes, needles, and the rest of the kit.
5.Reconstitution
| Vial sizes | 10 mg |
|---|---|
| Diluent | Bacteriostatic water for multi dose vials, or sterile water for single use |
| Concentration | Tanning doses are tiny, so mix dilute for an easy draw. Example: a 10 mg vial plus 5 mL of water gives 2 mg/mL, so a 200 mcg dose is 0.1 mL, which is 10 units on a U-100 syringe. |
| Notes | Melanotan II usually ships as 10 mg freeze dried vials. Because tanning doses are small, a more dilute mix is easier to measure accurately. |
Reconstitution calculator
Pick your vial size and how much water you add to see the draw volume and syringe units for a dose. Open the full calculator →
Inputs
Which do you know?
You want a set amount of compound. We show how many units to draw on the syringe.
Reminder: 1 mg = 1,000 mcg
Total amount stated on the vial, e.g. 5 mg.
How much diluent you draw into the vial.
Check this before you read the result. 1 mg = 1,000 mcg, so picking the wrong one is a 1,000x error, not a rounding error.
Result
Draw to
5 units
= 0.05 mL on a U-100 syringe
Easy draw: this dose comes out to a clean 5 units.
Aim for a dose that lands on an even number of units, like 10, 20, or 50. It is easier to draw accurately and to remember, and it keeps you off awkward repeating decimals.
- Concentration
- 5,000 mcg/mL
- Per unit
- 50 mcg / unit
- Doses per vial
- 40
Your settings live in the address bar, so a pasted link opens this calculator exactly as you left it.
Educational estimate only. Not medical or dosing advice. Verify every calculation independently before use.
6.Storage & stability
Lyophilized (dry)
| Temp | Freeze for long term storage, or 2 to 8 short term |
|---|---|
| Shelf life | Many months when frozen |
| Notes | Keep dry and out of light until you mix it. |
Reconstituted
| Temp | 2 to 8 (refrigerated) |
|---|---|
| Shelf life | About 2 to 4 weeks |
| Notes | Do not freeze after mixing. Discard if cloudy or discolored. |
7.Reported side effects
- SeriousRaised blood pressure and rare serious events(rare)s1Reports include atypical moles (dysplastic nevi) and rare events such as kidney infarction. Long term safety has not been studied.
- WarningNew or changing moles and freckles(common)s1It darkens existing moles and can create new ones. Any changing mole needs a dermatologist, because this can hide or mimic skin cancer.
- CautionNausea(common)s1Common right after a dose, and worse at higher doses.
- CautionFacial flushing(common)s1
- InfoDecreased appetite(common)s1
- InfoSpontaneous erections(common)s1More likely at the higher libido doses.
8.Interactions & stacking risks
- CautionPT-141 or other melanocortin agonists
They share a mechanism, so combining adds to the nausea and blood pressure effects.
9.Contraindications / who should avoid
- SeriousMany or atypical moles, or a personal or family history of melanoma
It changes moles and could hide or drive skin cancer. This is the most important reason to avoid it.
- SeriousUncontrolled high blood pressure or heart disease
It can raise blood pressure.
- SeriousPregnancy or breastfeeding
No safety data in pregnancy or breastfeeding.
10.COA & purity notes
| Common adulterants | underdosed or mislabeled vials, material sold without clear content |
|---|---|
| Mislabeling | It is unregulated, so a recent third party COA helps confirm what is in the vial. |
| Notes | Sold as an unapproved research and tanning chemical. |
11.Sources
Last reviewed 2026-07-08 · status: reviewed