Melanotan II
Synthetic Melanocortin Peptide · Tanning & Sexual Function
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.
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.
Research indications
What the compound has been studied for, grouped by body system. Effect size is the reported magnitude where it was measured — not a recommendation.
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.
A large effect in a weak study and a small effect in a strong one are different things. Effect size is never evidence of use in people.
- Class
- Synthetic alpha-MSH analog
- Half-life
- ~2 h
- Typical dose
- Loading: Start 0.25mg daily, increase to 0.5-1mg; Maintenance: 0.5-1mg 2-3x weekly
- Frequency
- Loading phase: Daily for first week, then tanning maintenance 2-3x weekly or as needed for sexual enhancement
- Cycle length
- 4-8 weeks loading phase for tanning, then ongoing maintenance as needed
- Storage
- Refrigerate at 2-8°C wrapped in aluminum foil (light-sensitive); use reconstituted solution within 4 weeks
Molecular data
- Type
- Synthetic alpha-MSH analog
- Half-life
- 120 min
Dosing reference
Doses reported in the literature and by suppliers. These are a record of what has been used in research — reference, never instruction.
| Context | Route | Amount | Frequency |
|---|---|---|---|
| Initial loading phase | SubQ | 0.25mg | 1x daily |
| Tanning maintenance | SubQ | 0.5-1mg | 2-3x weekly |
| Sexual enhancement | SubQ | 0.5-1mg | As needed |
| Minimal side effects | SubQ | 0.1-0.25mg | Every other day |
| Photoprotection | SubQ | 0.5mg | 2x weekly |
| Nasal administration | Nasal spray | 1-2mg | 1-2x daily |
| Localized tanning | Topical application | 1-2mg/mL solution | 1-2x daily |
Interactions
Both act on melanocortin receptors; combining may cause excessive side effects.
Redundant mechanism increases side effect risk.
May enhance sexual effects; monitor cardiovascular impact.
MT-II can affect blood pressure.
No known interactions.
Different pathways; no interactions.
MT-II has appetite-suppressing effects; additive effects possible.
Quality checklist
- ✓White to off-white lyophilized powder
- ✓Clear to pale yellow solution when reconstituted
- ✓Vacuum sealed vial with audible 'pop' when opening
- !Protect from light exposure - MT-II is photosensitive
- !Wrap vials in foil for storage
- ×Brown or dark powder indicates oxidation/impurities
- ×Cloudy solution after mixing indicates degradation/contamination
What to expect
Safety
- Nausea (pre-treatment with antiemetics recommended)
- Facial flushing
- Temporary blood pressure elevation
- Fatigue
- 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
FAQ
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.
How often should I take Melanotan II for sexual effects?
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.
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.
References
- 1Evaluation of Melanotan-II, a Superpotent Cyclic Melanotropic Peptide in a Pilot Phase-I Clinical StudyDorr RT, Lines R, Levine N, Brooks C, et al. · Life Sciences · 1996
Phase I study in 3 normal male volunteers. Daily subcutaneous injections for 2 weeks produced visible skin darkening in the face, upper body, and buttock after only 5 low doses.
reviewPubMed 8637402 ↗ - 2Melanocortin Receptor Agonists, Penile Erection, and Sexual Motivation: Human Studies with Melanotan IIWessells H, Levine N, Hadley ME, Dorr RT, Hruby VJ · International Journal of Impotence Research · 2000
20 men with psychogenic/organic ED; 0.025mg/kg dose. Melanotan II induced penile erection in 17/20 men without sexual stimulation. Increased sexual desire in 68% vs 19% placebo (P<0.01).
reviewPubMed 11035391 ↗ - 3Increased Eumelanin Expression and Tanning Is Induced by a Superpotent Melanotropin [Nle4-D-Phe7]-alpha-MSH in HumansDorr RT, Lines R, Levine N, et al. · Journal of Investigative Dermatology · 2000
Seven volunteers received 0.16mg/kg/day subcutaneous injections for 10 days. Mean 49% increase in forehead eumelanin and 98% increase in forearm eumelanin one week post-treatment.
human-pilotPubMed 11045725 ↗ - 4Discovery that a Melanocortin Regulates Sexual Functions in Male and Female HumansHadley ME, Dorr RT · Peptides · 2006
Melanotan II enhances sexual function in both males and females by working at the brain level, triggering a natural sexual response via melanocortin receptor activation.
reviewPubMed 15996790 ↗