Skin
Melanotan II
Sexual
7
Amino acids
Molecular weight
Peptide
Type
Melanotan II is a synthetic cyclic lactam analogue of alpha-melanocyte-stimulating hormone (alpha-MSH) that acts as a non-selective agonist at melanocortin receptors MC1R, MC3R, MC4R, and MC5R. It was originally developed to reduce skin cancer risk by stimulating melanogenesis without requiring UV exposure, and has since been studied in Phase II clinical trials for erectile dysfunction and female sexual arousal disorder. It is used in research and by self-administering individuals seeking enhanced pigmentation or improved sexual function.
Top researched benefits
Overview of Melanotan II
Melanotan II binds to and activates melanocortin receptors MC1R, MC3R, MC4R, and MC5R, triggering adenylate cyclase and cAMP signaling. MC1R activation drives melanin synthesis in melanocytes, while central MC4R activation mediates pro-erectile and appetite-suppressing effects via dopaminergic modulation.
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.
Typical Dose
Loading: 250 mcg per injection daily; maintenance dose: 100 mcg, 2–3x/week (half-life ~1.5 hours; daily or pre-event dosing recommended during loading)
Frequency
once daily during loading phase; 2–3x per week for maintenance
Cycle Duration
6–8 week loading cycle, then ongoing maintenance dosing
Storage
Lyophilized: store at -20°C (stable up to 24 months) or room temperature for up to 3 weeks. Reconstituted: store at 2–8°C and use within 14 days; avoid repeated freeze-thaw cycles.
Chemical Makeup
Key benefits
Stimulates melanin production in melanocytes via MC1R activation, producing skin darkening without requiring significant UV exposure
Demonstrated pro-erectile effects in Phase II clinical trials, with erections occurring in 17 of 20 men with erectile dysfunction in a double-blind placebo-controlled study (Wessells et al.)
Increases sexual desire in both men and women through central MC4R activation and dopaminergic pathway modulation
Suppresses appetite and reduces food intake via hypothalamic MC3R and MC4R signaling, with potential applications in metabolic research
Community interest
This peptide is still gaining traction in the community.
Melanocortin Agonist | Tanning & Sexual Function
This overview is informational and based on aggregated descriptions from studies and user reports.
Was it helpful?YesNoMelanotan II Molecular Information
View the scientifc details of Melanotan II.
7
Amino Acids
Melanotan II
?
?
Position 1
Asp
Asp
Position 2
His
His
Position 3
Phe
Phe
Position 4
Arg
Arg
Position 5
Trp
Trp
Position 6
Lys
Lys
Position 7
Molecular Weight
1024.18DaChain Length
7Amino AcidsType
PeptideMelanotan II Protocols
Subcutaneous injection is the primary and most bioavailable route for Melanotan II, typically administered into the abdomen, upper thigh, or upper arm. Injection is performed in the evening to exploit MT-II's MC3/MC4R agonism during overnight hours, reducing nausea during waking activity and aligning peak plasma levels with the following day's UV exposure.
| Goal | Dosage | Frequency | Route |
|---|---|---|---|
| Identify individual sensitivity threshold to MC3/MC4R agonism before escalating to full loading dose | 250 | 1 day range | SubQ (abdomen) |
| Build baseline melanogenesis and prime melanocyte response for UV-protective tanning effect | 500 | 1 day range | SubQ (abdomen or thigh) |
| Sustain established skin pigmentation with minimal ongoing UV exposure after loading cycle is complete | 500 | 2 week range | SubQ (abdomen or thigh) |
| Activate MC4R-mediated erectile and arousal pathways as a single pre-event dose consistent with Wessells et al. 2000 clinical trial design (25 mcg/kg) | 500 | 1 day range | SubQ, 60–90 min before anticipated sexual activity |
| Increase sexual desire and arousal through ongoing melanocortin receptor stimulation over a defined cycle | 500 | 1 day range | SubQ |
| Achieve maximum melanin density for competition-level skin pigmentation over an extended loading cycle | 1000 | 1 day range | SubQ (abdomen or thigh) |
Reconstitution Instructions
Materials needed:
Steps to reconstitute
- Wipe the rubber stopper of the Melanotan II vial and the bacteriostatic water vial with separate alcohol swabs and allow to air-dry for 30 seconds
- Draw 2 mL of bacteriostatic water into a 3 mL syringe
- Insert the needle into the Melanotan II vial and inject the water slowly down the inside wall of the vial — never directly onto the lyophilized powder
- Remove the syringe and gently swirl or tilt the vial until the powder is fully dissolved — do not shake
- Label the vial with the reconstitution date; refrigerate at 2–8°C and use within 4 weeks
- To draw a dose, insert a fresh insulin syringe into the reconstituted vial and pull back to the desired unit mark (10 mg vial in 2 mL = 5 mg/mL; 0.5 mg dose = 10 units on U-100 syringe)
- Choose an injection site — lower abdomen (at least 2 inches from the navel), upper outer thigh, or back of upper arm — and clean with an alcohol swab
- Pinch approximately 1 inch of skin and insert the needle at 45–90° depending on subcutaneous fat depth
- Inject the solution slowly and steadily, then withdraw the needle at the same angle and apply light pressure with a clean swab
- Rotate injection sites with each subsequent dose to prevent localized irritation
Melanotan II Cycle
The Melanotan II Cycle section explains how long a typical cycle lasts and what to expect during each phase. Over time, your body can become less responsive with continuous use.
Taking breaks between cycles may help maintain effectiveness and support better overall results.
- Day 1-3
- Possible nausea, flushing, fatigue
- Day 3-7
- Increased spontaneous erections (men), enhanced arousal
- Week 1-2
- Noticeable skin darkening, reduced appetite
- Week 2-4
- Significant tanning, stabilized sexual effects
- Week 0-0
- Maintained tan with less frequent dosing
Dosing tools
Melanotan II Peptide Dosage Calculator
Calculate peptide doses with our visual syringe guide.
mg
Enter the total amount of peptide in the vial in milligrams (as stated on the label).
The dose you want to inject per administration, in mcg or mg.
1,000 mcg = 1 mg
1 mL
2 mL
3 mL
5 mL
Custom
Volume of bacteriostatic water you add to reconstitute the powder. Use BAC water for preservation.
Injection Results
Based on your vial and dilution inputs.
Melanotan II
SINGLE COMPOUNDVolume per injection
0.05
mL
Concentration
10.00
mg/mL
Doses per vial
20
doses
Total injections per vial
20 injections
How it works
Based on a 10 mg Melanotan II vial diluted with 1 mL of bacteriostatic water, each 500 mcg injection equals 0.05 mL.
1mL / 100 units
5 units
0.050 mL
Reference Guide
Dosing Cycle
- Peptide
- Melanotan II
- Dosing
- Loading: 250 mcg per injection daily; maintenance dose: 100 mcg, 2–3x/week (half-life ~1.5 hours; daily or pre-event dosing recommended during loading)
- Dosing Frequency
- once daily during loading phase; 2–3x per week for maintenance
- Cycle Duration
- 6–8 week loading cycle, then ongoing maintenance dosing
- Storage
- Lyophilized: store at -20°C (stable up to 24 months) or room temperature for up to 3 weeks. Reconstituted: store at 2–8°C and use within 14 days; avoid repeated freeze-thaw cycles.
Note: Triple agonist; microdose for fewer side effects
Reconstitution Tips
- Use bacteriostatic water (BAC) — contains 0.9% benzyl alcohol for preservation
- Inject water slowly — aim down the vial wall, not directly onto powder
- Never shake — gently swirl or roll the vial until dissolved
- Store properly — refrigerate at 2-8°C after reconstitution
- Use within 28 days — most reconstituted peptides remain stable for about 4 weeks
- Keep sterile — always clean vial tops with alcohol before drawing
Peptide Interactions
Research suggestions of Melanotan II interactions with other common peptides and substances.
Side effects
Contraindications
History of melanoma or dysplastic nevi
Pregnancy or breastfeeding
Cardiovascular conditions
Uncontrolled hypertension
Stop signs
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)
Bad signs
Comments
0.0
0 reviews
5
4
3
2
1
No comments yet
Be the first to share your experience. Your review helps others make more informed decisions.
Frequently asked questions
What is a peptide dosage calculator?
A peptide dosage calculator is a free tool that converts your vial size, bacteriostatic water volume, and target dose into an exact syringe draw volume. Instead of doing the reconstitution math by hand, you enter three inputs and instantly get the concentration of your solution and how many milliliters or syringeunits to draw. This calculator works for single peptide compounds and multi-peptide blends.
How do I calculate peptide dosage from a vial?
To calculate your peptide dose, divide the total peptide content of your vial in micrograms by the volume of bacteriostatic water you added in milliliters. This gives you your solution concentration in mcg/mL. Then divide your target dose by that concentration to get your draw volume. For example, a 5mg (5,000 mcg) vial reconstituted with 2mL of BAC water gives a concentration of 2,500 mcg/mL. A 250 mcg dose would require drawing 0.1mL. This calculator automates all of those steps instantly.
How much Bacteriostatic water should I add to a peptide vial?
Most people add 2mL to 3mL of bacteriostatic water per vial, but the right amount depends on the dose you want to draw and the syringe size you are using. Adding 1mL to a 5mg vial gives you a concentration of 5,000 mcg/mL, making each dose very small in volume. Adding 2mL gives you 2,500 mcg/mL, which is easier to measure on a standard insulin syringe. A general guideline is to choose a volume that puts your typical dose somewhere between 10 and 30 units on a U-100 syringe. Use the calculator above to test different water volumes and find what works for your dose.
How are peptides different from proteins?
Both are made of amino acids, but peptides are much smaller than proteins. Because of their tiny size, peptides can act like tiny messengers in the body, sending specific signals to your cells to tell them exactly what to do.
Melanotan IIResearch References
Melanotan II is a phase 2 compound
Melanotan II
Melanotan II is a phase 2 compound
Erectile Dysfunction Phase II Trial
0.025mg/kg dose achieved 80% response rate with significant improvement in psychogenic ED over 3 months.
2000
Melanogenesis & UV Protection Study
0.16mg/kg daily for 10 days increased eumelanin and achieved natural tan without UV exposure.
1999
Female Sexual Arousal Disorder Trial
Single dose of 0.025mg/kg resulted in 73% of premenopausal women reporting arousal within 24 hours.
2004
Appetite Reduction Study
15% reduction in caloric intake observed through MC4R activation.
2001
Calculate peptide dosages
Learning how to calculate a peptide dose? Use our beginner-friendly peptide dosage, blend, and accumulation calculators. Enter vial size, reconstitution volume, and target dose to get exact draw volumes instantly. No guesswork, just clear guidance that helps prevent common mistakes.
