Melanotan II (MT-2)
Well StudiedSynthetic alpha-MSH analog
Melanotan II (MT-2) is a synthetic cyclic heptapeptide analog of alpha-melanocyte stimulating hormone. It has been studied in research contexts for its activity at melanocortin receptors, including MC3R and MC4R. Published research has explored its receptor binding properties and downstream signaling pathways. RaysunPeptide supplies Melanotan II for qualified research and laboratory applications.
Mechanism of Action
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.
Key Benefits
Molecular Data
Dosing Protocols
| Goal | Dose | Frequency | Route |
|---|---|---|---|
| Initial loading phase | 0.25mg | 1x daily | SubQ |
| Tanning maintenance | 0.5-1mg | 2-3x weekly | SubQ |
| Sexual enhancement | 0.5-1mg | As needed | SubQ |
| Minimal side effects | 0.1-0.25mg | Every other day | SubQ |
| Photoprotection | 0.5mg | 2x weekly | SubQ |
Research Indications
Skin Health
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.
Sexual Health
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.
Metabolic
MC4R activation in hypothalamus reduces appetite (15% caloric intake reduction in studies).
Enhanced fat oxidation through metabolic pathway activation.
Peptide 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.
What to Expect
Side Effects & Safety
Common (Generally Mild)
- •Nausea (pre-treatment with antiemetics recommended)
- •Facial flushing
- •Temporary blood pressure elevation
- •Fatigue
- •Spontaneous erections
Stop Signs (Seek Medical Attention)
- ⚠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)
Contraindications
- ✕History of melanoma or dysplastic nevi
- ✕Pregnancy or breastfeeding
- ✕Cardiovascular conditions
- ✕Uncontrolled hypertension
Quality Checklist
Good Signs ✓
- White to off-white lyophilized powder
- Clear to pale yellow solution when reconstituted
- Vacuum sealed vial with audible 'pop' when opening
Warning Signs !
- Protect from light exposure - MT-II is photosensitive
- Wrap vials in foil for storage
Bad Signs ✕
- Brown or dark powder indicates oxidation/impurities
- Cloudy solution after mixing indicates degradation/contamination
References
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).
View on PubMed →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.
View on PubMed →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.
View on PubMed →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.
View on PubMed →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.
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.
