The math for this vial
- Concentration: 40 mg ÷ 2 mL = 20 mg/mL (20,000 mcg/mL).
- Volume of one U-100 unit: 1 ÷ 100 = 0.01 mL.
- Mass in one unit: 20,000 mcg/mL × 0.01 mL = 200 mcg.
- The whole vial is 200 U-100 units of solution, more than one 1 mL syringe holds.
On a U-40 syringe each unit is 0.025 mL, so each unit holds 2.5 times as much: 500 mcg at 2 mL. See U-100 vs U-40 units.
Unit chart
What common U-100 readings hold from a 40 mg vial, by water volume.
| Units | mL | 1 mL water | 2 mL water | 3 mL water |
|---|---|---|---|---|
| 1 | 0.01 | 400 mcg | 200 mcg | 133.3 mcg |
| 5 | 0.05 | 2 mg | 1 mg | 666.7 mcg |
| 10 | 0.1 | 4 mg | 2 mg | 1.333 mg |
| 20 | 0.2 | 8 mg | 4 mg | 2.667 mg |
| 25 | 0.25 | 10 mg | 5 mg | 3.333 mg |
| 50 | 0.5 | 20 mg | 10 mg | 6.667 mg |
| 100 | 1 | 40 mg | 20 mg | 13.333 mg |
About this vial size
40 mg is the largest common MOTS-c vial. Across the water volumes above, one U-100 unit holds between 133.3 mcg (at 3 mL) and 400 mcg (at 1 mL). Compared with a 10 mg vial at the same water volume, it is 4 times as concentrated, so the same mass takes 0.25 times the units.
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.
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.
MOTS-c is not an approved drug. A 2026 advisory vote recommended it for the pharmacy compounding list, which requires rulemaking before it takes effect.