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 | 1.3 mg | 2.7 mg | 4 mg |
|---|---|---|---|---|
| 80 mg vial + 2 mL water | 40 mg/mL | 3 u | 7 u | 10 u |
| 80 mg vial + 3 mL water | 26.6667 mg/mL | 5 u | 10 u | 15 u |
| 80 mg vial + 4 mL water | 20 mg/mL | 7 u | 13 u | 20 u |
| 10 mg vial + 2 mL water | 5 mg/mL | 27 u | 53 u | 80 u |
| 10 mg vial + 3 mL water | 3.33333 mg/mL | 40 u | 80 u | 120 u |
| 10 mg vial + 4 mL water | 2.5 mg/mL | 53 u | 107 u | 160 u |
Worked example: a 80 mg vial with 3 mL of bacteriostatic water is 26.6667 mg/mL. A 2.7 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.
3 mL is the usual choice: 80 mg ÷ 3 mL = 26.67 mg/mL, so a 2,670 mcg draw is 0.10 mL = 10 units. 2 mL gives 40 mg/mL (the same draw = 7 units); 4 mL gives 20 mg/mL (13 units).
KLOW is GLOW plus KPV. GLOW is a 70 mg blend (GHK-Cu 50, BPC-157 10, TB-500 10); KLOW adds 10 mg of KPV for 80 mg total. Use the GLOW calculator for the three-peptide blend.
Multiply the draw by each peptide's share of the vial: GHK-Cu 50/80 (62.5%), BPC-157, TB-500 and KPV 10/80 (12.5%) each. The calculator above shows the combined units; the split follows the 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.
🎁 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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