OnePeptideShip

Melanotan II Research Profile

Research Use

Melanotan II is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It stimulates melanogenesis for skin darkening, while also acting centrally as a potent appetite suppressant and aphrodisiac.

Melanotan II Quick Technical Specifications

Category
Melanocortin Agonist
Elimination Half-Life
approx. 1 hour
Storage Protocol
Refrigerated (2°C-8°C)
Status
Research Use
OE
Written by OnePeptideShip Editorial Team
Reviewed by Dr. Aris Thorne, MD, Board Certified Endocrinology Advisor
Updated September 2026

Mechanism of Action & Biochemical Context

Melanotan II is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It stimulates melanogenesis for skin darkening, while also acting centrally as a potent appetite suppressant and aphrodisiac.

Storage, Reconstitution & Stability Guidelines

Prior to reconstitution, lyophilized Melanotan II powder should be stored away from light between 2°C and 8°C for short-term access, or -20°C for long-term preservation. Once reconstituted with Bacteriostatic Water (0.9% benzyl alcohol preservative), maintain strict refrigeration between 2°C and 8°C. Do not freeze liquid solution.

Cited Scientific References

  1. Dorr RT, et al. Evaluation of Melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sci. 1996.

Calculate Melanotan II Syringe Units

Input your vial mg and BAC water mL to calculate exact U-100 draw units.

Open Melanotan II Calculator →

Frequently Asked Questions

From a 10mg vial with 2mL of BAC water (concentration: 5,000mcg/mL), a 250mcg dose is just 0.05mL = 5 units on a U-100 syringe. This is an extremely small draw - many researchers add more water (e.g., 4mL) to create a less concentrated 2,500mcg/mL solution, making a 250mcg dose a more manageable 10 units.

MT2 will produce melanin and darkening without any UV light, but the results are dramatically enhanced by UV exposure. The UV light acts as a "trigger" that activates the melanocytes that MT2 has already primed. Researchers typically combine MT2 with 10-15 minutes of natural sunlight or tanning bed exposure for the fastest and most even results. Without UV, the color produced is sometimes described as ashy or grayish rather than a golden tan.

A standard research protocol uses a loading phase of 250-500mcg per day for 10-20 days (with UV exposure) until the desired skin tone is achieved. This is followed by a maintenance phase of 250-500mcg one to two times per week (with brief UV exposure) to maintain the color. Some researchers use an even lower maintenance dose of 100-250mcg once weekly.

MT2 stimulates melanocytes throughout the body without discrimination. Pre-existing freckles and moles will become significantly darker (sometimes appearing black). There is no way to fully prevent this. Researchers with a large number of moles should: start with a very low micro-dose (100mcg) to observe the response, have a dermatologist baseline-photograph moles before starting, and avoid high doses entirely.

Melanotan face (severe, uneven darkening of the face, lips, and existing pigmented spots) occurs from overdosing. Because the concentration is so high (5,000mcg/mL), even a slightly high dose (20 units instead of 5 units) is a massive 4x overdose. Always use precise, small draw volumes and consider further diluting the vial.

Melanotan I (Afamelanotide) is a linear peptide that is selective only for the MC1R receptor in the skin. It does NOT cross the blood-brain barrier effectively, meaning it does not cause nausea, appetite suppression, or sexual side effects. MT1 is significantly safer from a side-effect profile but is much more expensive and less widely available. MT2 crosses the blood-brain barrier and causes all the systemic central effects.

Yes. MT2 activates both the MC3R and MC4R receptors centrally, which are major regulators of energy balance and appetite. Many researchers report a significant reduction in hunger and food cravings while using MT2. This appetite-suppressing effect is separate from and in addition to the tanning and sexual arousal effects.