Published by Peptide Protocols · Reviewed September 2026 · How we make these pages · Educational & research purposes only — not medical advice.
1 mL = 100 units on a U-100 insulin syringe. Formula: mg ÷ mL = mg/mL; (mcg ÷ 1000) ÷ mg/mL = mL; mL × 100 = units.
Units to draw on a U-100 insulin syringe for the common vial sizes and water volumes. Pick the row that matches your vial and the water you added.
| Vial + water | Concentration | 1.2 mg | 2.3 mg | 3.5 mg |
|---|---|---|---|---|
| 70 mg vial + 2 mL water | 35 mg/mL | 3 u | 7 u | 10 u |
| 70 mg vial + 3 mL water | 23.3333 mg/mL | 5 u | 10 u | 15 u |
| 70 mg vial + 4 mL water | 17.5 mg/mL | 7 u | 13 u | 20 u |
| 10 mg vial + 2 mL water | 5 mg/mL | 23 u | 47 u | 70 u |
| 10 mg vial + 3 mL water | 3.33333 mg/mL | 35 u | 70 u | 105 u |
| 10 mg vial + 4 mL water | 2.5 mg/mL | 47 u | 93 u | 140 u |
Worked example: a 70 mg vial with 3 mL of bacteriostatic water is 23.3333 mg/mL. A 2.3 mg draw is 0.10 mL, which is 10 units. Change the water and every number on the syringe changes — which is the single most common reconstitution mistake. The full explanation is in How to Reconstitute Peptides.
Add bacteriostatic water slowly down the inside wall of the vial (never sprayed onto the powder), then swirl gently until clear. With 3 mL in a 70 mg vial the concentration is 23.33 mg/mL, so a 2,330 mcg draw is 0.10 mL = 10 units on a U-100 syringe. The full method is in How to Reconstitute Peptides.
3 mL is the common choice for the 70 mg vial (23.33 mg/mL). 2 mL gives 35 mg/mL and a 2,330 mcg draw of 7 units; 4 mL gives 17.5 mg/mL and 13 units.
By the total. Research references quote the combined draw (for example 2,000–3,500 mcg); each peptide is present in the vial's fixed 5:1:1 ratio.
We do not recommend or partner with any peptide supplier. Use the checklist instead: third-party COAs that match your batch and lot, stated purity, clear research-use labeling, real support and proper cold-chain shipping.
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The one formula, a BAC-water chart, and the 10 most-researched beginner peptides — the math done for you. Print it for the fridge.
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