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This is plain-language harm-reduction information, not medical advice. Peptides discussed here are research compounds; most are not approved for human use. People will use them either way — we would rather they have the facts.
What it is
Melanotan II is a synthetic analogue of alpha-melanocyte-stimulating hormone (α-MSH). It darkens skin by stimulating melanin production, and as a side effect it also activates melanocortin receptors involved in sexual function.
It is one of the older grey-market peptides and probably the one with the largest body of community use experience.
History
Developed at the University of Arizona in the 1990s as a way to induce protective tanning that might reduce skin cancer risk in pale-skinned populations. Never made it through trials but found a community use case anyway.
How it works
Activates the MC1R receptor (melanin production) and other melanocortin receptors involved in appetite suppression, sexual arousal and inflammation.
Dosage
- Loading phase: 250 mcg daily for 5–7 days, then 500 mcg daily until desired colour is reached.
- Maintenance: 500–1000 mcg twice weekly with some UV exposure to maintain tan.
How it is taken
- Subcutaneous injection. UV exposure (sun or sunbed) still required for tanning effect.
How to reconstitute
- 10 mg vial with 2 ml BAC water = 5 mg/ml. 250 mcg = 5 units on a 1 ml insulin syringe.
How it should arrive
White powder, sealed vial.
How it should look once reconstituted
Clear colourless solution.
What to expect, and when
- Tan development: 2–6 weeks of consistent use plus moderate UV exposure.
- Other effects (appetite, libido): often within 1–3 doses.
Side effects
- Nausea after injection — almost universal in the loading phase, fades.
- Spontaneous erections, sometimes prolonged.
- Increased appetite suppression.
- Darkening of moles and freckles — important to track. New moles or sudden changes to existing ones should be checked by a dermatologist.
- Facial flushing.
Risks
- Mole darkening can mask early melanoma signs. Get a dermatologist to map and track moles before starting.
- Long-term safety data does not exist.
- Some users develop persistent darkening that does not fully reverse on stopping.
Potential gains
- Faster, deeper tan with less UV exposure than the same tan would otherwise require.
- Some sexual function enhancement (related compound PT-141 is the pure libido version).
Other useful information
PT-141 is the libido-focused derivative. If the tanning is the goal, MT-II; if the sexual function is the goal, PT-141. People with lots of moles or family history of melanoma should think carefully before using this.
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