Growth & hormones · ~3 min read
Melanotan II: What It Is, How It Works & What the Research Shows
Overview
Melanotan II is a cyclic analog of alpha-MSH that activates several melanocortin receptors (MC1, MC3 and MC4), not just the skin-pigment receptor. This produces skin tanning along with increased sexual arousal and reduced appetite. Common side effects include nausea, facial flushing, and darkening or changes in moles. It was never approved as a medicine; bremelanotide (PT-141) was developed from it.
Why researchers study it
Tanning
Darkens skin with less UV exposure.
Libido
Increases sexual arousal through MC4R.
Appetite
Explored for appetite suppression.
How it works
An experimental melanocortin agonist studied for pigmentation and central sexual-response effects. Activity across receptor subtypes can also produce unwanted effects.
Adamantane & the blood–brain barrier
Chemically attaching an adamantane group to a peptide can increase its lipid (fat) solubility. Researchers hypothesize that this modification may help certain compounds cross the tightly regulated blood–brain barrier. The effect depends on the specific modified molecule; greater lipid solubility alone does not establish brain delivery or clinical benefit. This does not apply automatically to the unmodified peptide and is not a reconstitution additive.
What the research shows
- Pigmentation, appetite, and sexual-response effects have been investigated.
Typical protocol
Reconstitute a 10 mg vial with 3 mL bacteriostatic water for 3.3333 mg/mL. Typical range: 250–1000 mcg 1x daily · daily, 4–12 weeks (then maintenance).
Potential benefits & side effects
Potential benefits
- Deeper, longer-lasting tan with less UV exposure (Melanotan)
- Increased sexual desire and arousal (PT-141, Melanotan II)
- Appetite suppression (Melanotan II)
Side effects
- Nausea (most common)
- Facial flushing
- Darkening of freckles and moles
- Temporary rise in blood pressure (PT-141)
- Spontaneous erections (Melanotan II, PT-141)
Lifestyle factors
- Start low: nausea is dose-related.
- Dose in the evening to sleep through nausea and flushing.
- UV: tanning still requires sun exposure — use sensible exposure and protection.
- Check moles regularly and see a dermatologist for any changes.