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Melanotan II Reconstitution Calculator

Research Use

Calculate precise U-100 syringe units, concentration (mg/mL), and doses per vial for Melanotan II research.

Clinical Precision Tool

Melanotan II Dosage Calculator

U-100 Calibrated
Calculated Syringe Draw
5.0Units
➜ 0.050 mL volume
0 Units100 Units Max
Concentration
5.00 mg/mL
Tick Marks
5.0 ticks
OE
Written by OnePeptideShip Editorial Team
Reviewed by Dr. Aris Thorne, MD, Board Certified Endocrinology Advisor
Updated September 2026

Clinical Pharmacology & Mechanism of Action

Melanotan II (MT2) is a synthetic cyclic heptapeptide analog of the naturally occurring alpha-melanocyte-stimulating hormone (α-MSH). It was originally developed at the University of Arizona to induce melanogenesis (the production of melanin) without requiring dangerous levels of ultraviolet (UV) exposure, theoretically offering protection against skin cancer.

MT2 works by acting as a non-selective agonist of the melanocortin receptors in the body, primarily MC1R, MC3R, MC4R, and MC5R.

  • MC1R Agonism: This receptor is located in the skin. Activation strongly stimulates melanocytes to produce melanin, resulting in profound skin darkening (tanning) even in individuals with very fair skin types (Fitzpatrick Type 1 or 2) .
  • MC4R Agonism: Because it crosses the blood-brain barrier and binds to MC4R, it also acts as a potent appetite suppressant and a strong aphrodisiac (causing spontaneous erections and sexual arousal), identical to the mechanism of PT-141.

Pharmacokinetics & UV Synergism

  • Half-life: Approximately 1 to 2 hours.
  • UV Requirement: While MT2 will produce melanin independently, its effects are exponentially magnified by UV exposure. Clinical protocols generally combine low-dose MT2 administration with brief (10-15 minutes) of natural sunlight or tanning bed exposure to trigger the melanocytes.

Standard Research Dosing Protocols

MT2 is incredibly potent, and side effects (nausea, intense facial flushing, new freckles, and darkening of existing moles) are highly dose-dependent. The modern research consensus has shifted away from massive "loading phases" toward micro-dosing.

  • Assessment Dose (Days 1-3): 100mcg to 250mcg per day. (Used strictly to assess nausea tolerance).
  • Maintenance Dose: 250mcg to 500mcg per day, injected roughly 30 minutes before UV exposure.
  • Frequency: Daily until the desired skin tone is achieved, then dropped to 1-2 times per week to maintain the color.

Reconstitution Math & Syringe Guide

Melanotan II is universally sold in 10mg vials. Because the clinical dose is tiny (often 250mcg), it is very easy to overdose if the math is calculated incorrectly.

Step-by-Step Reconstitution (10mg Vial)

  1. Swab the rubber stoppers of your 10mg MT2 vial and Bacteriostatic Water.
  2. Using a sterile mixing syringe, draw exactly 2mL of Bacteriostatic Water.
  3. Inject the water slowly down the inside wall of the MT2 vial.
  4. Swirl gently. Wait for it to dissolve completely.

The Math for a Standard Dose (250mcg):

  • 10mg total in the vial = 10,000mcg.
  • You added 2mL of water.
  • Therefore, the concentration is 5,000mcg per 1mL.
  • You need a 250mcg dose. Divide the dose by the concentration: 250 ÷ 5,000 = 0.05mL.
  • 0.05mL = 5 units on a U-100 syringe.

(For a 500mcg dose: 500 ÷ 5,000 = 0.10mL, which is 10 units).

Common Mistakes & Troubleshooting

  • Massive Overdosing: A 10mg vial contains forty 250mcg doses. Because 5 units looks like barely a drop of liquid in a syringe, researchers often assume it's not enough and draw 20 or 30 units. This leads to horrific nausea, vomiting, and "Melanotan face" (hyperpigmentation of the lips and deep blackening of moles).
  • Ignoring Moles: MT2 does not distribute melanin perfectly evenly. It will preferentially darken areas with high melanocyte density. Pre-existing freckles and moles will darken significantly, often appearing black. If you have a high mole count, micro-dosing (100mcg) is highly recommended.
  • Using without UV: While MT2 works without UV, relying entirely on the peptide without a UV trigger often results in a grayish/dirty skin tone rather than a golden tan.

Medical & Research Disclaimer

The information provided on this page, including all calculations, is for educational and laboratory research purposes only. It does not constitute medical advice. Peptides mentioned here are not approved for human consumption outside of FDA-approved clinical trials unless specified otherwise. Always consult a licensed healthcare provider before undertaking any new therapy.

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.

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