Melanotan II
MT-2 · MT-II
A melanocortin agonist that tans skin and raises libido — with a notably troublesome side-effect profile.
Class
Non-selective melanocortin receptor agonist
Half-life
~1–2 hours (variable)
Evidence
Limited human data
Limited human data
Small open-label studies, case series, or trials in a narrow population. Directionally informative, not conclusive.
Overview
Melanotan II is a synthetic analogue of α-MSH that activates melanocortin receptors broadly — including MC1R (skin pigmentation) and MC4R (sexual function and appetite). It is used primarily to darken skin ('injectable tanning') and secondarily for libido, essentially a less selective cousin of PT-141.
That lack of selectivity is the problem. Activating MC1R produces tanning but also drives new and darkening moles, and there are documented case reports of changes in existing moles and concern about melanoma. The broad melanocortin activity also causes nausea, facial flushing, and spontaneous erections.
It has no approval anywhere and a worse risk profile than the approved, more selective PT-141. It is included here because it is widely sold and used, and people deserve a clear-eyed account of why it warrants real caution, particularly around skin cancer risk.
How it works
- Non-selectively agonises melanocortin receptors (MC1R, MC3R, MC4R, MC5R).
- MC1R activation drives melanogenesis (tanning) and mole changes.
- MC4R activation increases sexual arousal and suppresses appetite.
- Broad activity produces its wide and unpredictable side-effect spread.
What the research shows
Researched effects
- Skin darkening with reduced UV exposure needed to tan
- Increased libido and spontaneous erections
- Appetite suppression
- Documented mole darkening and new nevi formation
Limitations & what it won't do
- Non-selective — causes pigmentation, appetite, and sexual effects together whether wanted or not.
- Documented concern about melanoma and changes to existing moles.
- No approval and no controlled safety trials.
- Product purity is unregulated.
Dosing protocols
These ranges reflect published trials and community protocols. They are reference information, not a prescription. Doses are per injection unless noted.
Community protocol (caution advised)
Loading 250–500 mcg; maintenance 500–1000 mcgDocumented for reference. Given the melanoma concern, a full skin/mole check before and during use is strongly advised.
Reconstitution & measuring your dose
Handling
- Typical vial sizes
- 10 mg
- Suggested BAC water
- 2 mL
- Storage
- Lyophilised powder refrigerated at 2–8 °C, protected from light.
- After reconstitution
- Reconstituted: approximately 30 days refrigerated.
Why 2 mL? A 10 mg vial in 2 mL yields 5000 mcg/mL — 250 mcg lands on 5 units, 500 mcg on 10 units of a U-100 syringe.
Dose calculator
Draw to
5units
= 0.05 mL · 50 mcg per unit
Concentration
5000 mcg/mL
Doses per vial
40
Side effects
Common
- Nausea (especially at first)
- Facial flushing
- Spontaneous erections
- Darkening of moles and freckles
- Appetite suppression
- Injection-site reactions
Serious / rare
- Changes to existing moles / concern for melanoma
- Priapism (painful prolonged erection)
- Rhabdomyolysis reported rarely
- Blood pressure changes
Contraindications & interactions
Do not use if you have
- Melanoma, atypical moles, or high skin-cancer risk
Melanotan II drives melanocyte activity and mole changes. A history of melanoma, atypical moles, or heavy mole burden is an absolute contraindication.
- Active cancer or current oncology treatment
Avoid during active malignancy.
- Pregnant, breastfeeding, or trying to conceive
No pregnancy safety data.
Use caution if you have
- Cardiovascular disease
Blood pressure changes warrant caution with cardiovascular disease.
- High blood pressure
Can affect blood pressure.
Medication interactions
- avoidNitrates — Vasoactive effects combined with nitrates are risky.
Don't stack with
- PT-141 (Bremelanotide) — Both melanocortin agonists — additive nausea, pigmentation, and cardiovascular effects.
What to monitor
- Full skin and mole examination before and periodically during use — the single most important safeguard
- Blood pressure
References
Research & educational information only — not medical advice.
You must be 18 or older to use this site. The peptides described are presented as research chemicals intended for research purposes only. Most are not approved by the FDA for human use. Dosing ranges reflect what has appeared in the scientific literature or community protocols and are not prescriptions. Nothing here replaces evaluation by a licensed physician who knows your full medical history.
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