Worked example
Add 2 mL of water to a vial holding 10 mg of MOTS-c. The concentration is 10 ÷ 2 = 5 mg/mL, or 5,000 mcg in every millilitre. On a U-100 syringe, where 100 units make 1 mL, each unit holds 50 mcg and each 10 units hold 500 mcg.
Change the water and only the concentration changes. With 4 mL instead, each 10 units hold 250 mcg, half as much, and any given mass takes twice the units to measure. These numbers illustrate the arithmetic; they are not amounts to use.
Concentration table
Common MOTS-c vial sizes against common water volumes. The last column is what 10 units on a U-100 syringe hold.
| Vial | Water | Concentration | 10 units (U-100) hold |
|---|---|---|---|
| 5 mg | 1 mL | 5 mg/mL | 500 mcg |
| 5 mg | 2 mL | 2.5 mg/mL | 250 mcg |
| 5 mg | 3 mL | 1.667 mg/mL | 166.7 mcg |
| 10 mg | 1 mL | 10 mg/mL | 1 mg |
| 10 mg | 2 mL | 5 mg/mL | 500 mcg |
| 10 mg | 3 mL | 3.333 mg/mL | 333.3 mcg |
| 40 mg | 1 mL | 40 mg/mL | 4 mg |
| 40 mg | 2 mL | 20 mg/mL | 2 mg |
| 40 mg | 3 mL | 13.333 mg/mL | 1.333 mg |
Notes for MOTS-c vial math
- The jump from a 10 mg to a 40 mg vial quadruples concentration at the same water volume. At 40 mg in 2 mL (20 mg/mL), one U-100 unit holds 200 mcg.
- MOTS-c is 16 amino acids and about 2,175 g/mol, roughly 1.5 times the mass of BPC-157 per molecule. That does not change the vial math, which is mass-based, but it matters when comparing studies that report molar amounts.
- MOTS-c contains methionine, which oxidizes readily. Oxidized peptide still weighs the same, so the calculator cannot detect degradation.
Storage and handling
- No approved label or validated in-use stability data exists. Methionine-containing peptides are prone to oxidation, so minimize air exposure and light.
- General practice: refrigerate reconstituted vials (2-8 °C), avoid freezing and repeated warming, label with date and concentration.