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 | 500 mcg | 1 mg | 2 mg |
|---|---|---|---|---|
| 2 mg vial + 1 mL water | 2 mg/mL | 25 u | 50 u | 100 u |
| 2 mg vial + 2 mL water | 1 mg/mL | 50 u | 100 u | 200 u |
| 2 mg vial + 3 mL water | 0.666667 mg/mL | 75 u | 150 u | 300 u |
| 5 mg vial + 1 mL water | 5 mg/mL | 10 u | 20 u | 40 u |
| 5 mg vial + 2 mL water | 2.5 mg/mL | 20 u | 40 u | 80 u |
| 5 mg vial + 3 mL water | 1.66667 mg/mL | 30 u | 60 u | 120 u |
| 10 mg vial + 1 mL water | 10 mg/mL | 5 u | 10 u | 20 u |
| 10 mg vial + 2 mL water | 5 mg/mL | 10 u | 20 u | 40 u |
| 10 mg vial + 3 mL water | 3.33333 mg/mL | 15 u | 30 u | 60 u |
Worked example: a 2 mg vial with 2 mL of bacteriostatic water is 1 mg/mL. A 1 mg draw is 1.00 mL, which is 100 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.
1 mL gives 2 mg/mL (a 1 mg draw = 0.5 mL = 50 units); 2 mL gives 1 mg/mL (a 1 mg draw = 1 mL = 100 units, a full syringe). Choose the volume that keeps your intended draw comfortably inside the syringe.
Because the peptide is spread through more liquid. The amount of tesamorelin in the vial never changes — only how much of it sits in each 0.01 mL tick.
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.
The supplier checklist →Educational content only. Confirm the legal status where you live before ordering anything.
The one formula, a BAC-water chart, and the 10 most-researched beginner peptides — the math done for you. Print it for the fridge.
🎁 Send me the free cheat sheet →Every cheat sheet in the shop includes the Universal Excel Logbook — it auto-calculates reconstitution and tick marks for 38+ peptides and keeps a dated record of each vial.
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