Melanotan II (MT-II)

Synthetic Melanocortin Peptide · Tanning & Sexual Function

Overview

Melanotan II is a synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH) that activates melanocortin receptors throughout the body. MC1R activation triggers melanin production for tanning, while MC4R affects sexual arousal and appetite control.

Binds to melanocortin receptors (MC1R for tanning, MC4R for sexual function and appetite) to stimulate melanin production, enhance libido, and suppress appetite through hypothalamic pathways.

Stimulates natural melanin production for tanning without requiring UV exposure.

Increased melanin provides natural SPF protection against sun damage.

May help address certain pigmentation disorders.

Improves sexual desire in both men and women through MC4R activation.

Mechanism

Binds to melanocortin receptors (MC1R for tanning, MC4R for sexual function and appetite) to stimulate melanin production, enhance libido, and suppress appetite through hypothalamic pathways.

Stimulates natural melanin production for tanning without requiring UV exposure.

Research areas

Melanotan II is a synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH) that activates melanocortin receptors throughout the body. MC1R activation triggers melanin production for tanning, while MC4R affects sexual arousal and appetite control.
Binds to melanocortin receptors (MC1R for tanning, MC4R for sexual function and appetite) to stimulate melanin production, enhance libido, and suppress appetite through hypothalamic pathways.
Stimulates natural melanin production for tanning without requiring UV exposure.
Increased melanin provides natural SPF protection against sun damage.
May help address certain pigmentation disorders.
Improves sexual desire in both men and women through MC4R activation.
80% response rate in psychogenic erectile dysfunction studies.
73% of women reported arousal within 24 hours in clinical trials.
MC4R activation in hypothalamus reduces appetite (15% caloric intake reduction in studies).
Enhanced fat oxidation through metabolic pathway activation.

Research notes

Nausea (pre-treatment with antiemetics recommended)
Facial flushing
Temporary blood pressure elevation
Spontaneous erections
Severe persistent nausea or vomiting
Chest pain or significant blood pressure elevation
Mole changes (size, shape, color) - monitor closely
Prolonged painful erections (priapism)
Severe headaches or vision changes
Allergic reactions (rash, swelling, breathing difficulty)
History of melanoma or dysplastic nevi
Pregnancy or breastfeeding
Cardiovascular conditions
Uncontrolled hypertension
Melanotan II can be used as-needed for sexual enhancement (0.5-1mg), though some users inject 2-3x weekly for maintained libido benefits. Sexual effects develop within hours and peak around 3-5 hours post-injection, so timing around sexual activity is practical.

Pharmacokinetics

Stimulates natural melanin production for tanning without requiring UV exposure.

Protocol Variations

Multiple approaches exist - compare before choosing
Different sources recommend different protocols for this peptide. Review each approach and consider your goals, tolerance, and experience level before choosing.

Traditional Loading Protocol

Source: Legacy Bodybuilding Forums
"Aggressive daily loading to build melanin quickly"
A decade-old protocol involving daily injections at higher doses for 1-2 weeks before maintenance. This approach is associated with more side effects including nausea and increased freckling/mole development. Dosing on non-tanning days can lead to uneven pigmentation.
Higher starting doses (250-500mcg)
Daily dosing regardless of tanning
1-2 week loading period before UV exposure
Higher risk of nausea, freckling, and new moles
Can cause uneven tanning when UV begins

Pre-Tan Only Protocol

Source: More Plates More Dates
"ONLY dose on tanning days - loading phase is unnecessary"
NEVER administer on non-tanning days. Always tan within 1 hour of injection. Start extremely low (50-75mcg) and increase by 25mcg every 3 sessions. This dramatically reduces freckling, uneven pigmentation, and side effects. The traditional loading phase is considered counterproductive - it builds melanin in areas with high melanocyte activity (freckles, moles, genitals) rather than where UV protection is needed.
Start at only 50-75mcg (much lower)
ONLY inject on days you tan - never otherwise
Must tan within 1 hour of injection
Increase dose by 25mcg every 3 sessions
Also increase tan time by 1 min per 3 sessions
Takes weeks/months to reach higher doses
Minimal freckling and side effects
More economical and sustainable long-term

AXIOM catalogue

MT2 — research-use catalogue record with strengths and available batch details where listed.

References

FAQs

Which Melanotan II protocol causes less nausea—loading or pre-tan only?

The pre-tan-only protocol causes significantly less nausea because you only inject on tanning days at very low starting doses (50-75mcg). The traditional loading phase with daily injections at higher doses causes much more nausea. Starting extremely low and increasing gradually by 25mcg minimizes side effects.

Does Melanotan II really enhance sexual function?

Yes. Clinical trials show 80% response rate for erectile function in men with psychogenic ED and 73% of women reporting arousal within 24 hours. Effects are achieved through MC4R activation in the brain, triggering natural sexual responses without direct genital action.

Will Melanotan II cause permanent mole changes?

Possible. MT-II activates melanocortin receptors broadly, including in existing moles and freckles. Some users report permanent enlargement or darkening of existing moles. Regular skin monitoring is essential—any rapidly changing mole requires dermatology evaluation regardless of MT-II use.