Melanotan II

What people use it for

• Skin tanning (popular use)
• Libido (side effect that led to PT-141)

What Melanotan II does in the body

Activates several melanocortin receptors. Stimulating MC1R increases melanin production (tanning), while effects on MC3R/MC4R influence appetite and sexual function.

Strength of evidence

Limited: small early studies; no approved medical use.

Look up the evidence

• Reviews on PubMed: Summaries of the published research
• Clinical trials on PubMed: Published studies in people
• ClinicalTrials.gov: Registered trials, past and ongoing

Live searches of official databases. New to the terms? See the glossary.

Reported side effects & risks

• Nausea, flushing, reduced appetite
• New or darkening moles — have changing moles checked by a doctor
• Spontaneous erections / priapism
• Unknown long-term skin-cancer risk

Who should avoid it or take extra care

• History of melanoma, or many or unusual moles
• Pregnant or breastfeeding
• High blood pressure or heart disease

Not a complete list. Check with a doctor or pharmacist about your own health and medicines.

Regulatory status

Not approved. Health regulators in several countries have issued public warnings against its use.

How it's taken

Route: Injection under the skin or nasal spray (unofficial use)

How long it lasts (half-life): Not well established

Storage

Unreconstituted (powder) vials are usually kept refrigerated or frozen and away from light. Once mixed with bacteriostatic water, keep refrigerated and do not freeze; follow the supplier's stated beyond-use date.

Mixing guides

How much water to add and what each syringe mark holds, worked out for your own dose:

• 10 mg vial