How to Use U-40 Insulin in a U-100 Syringe

Insulin dosages are measured in units of insulin rather than in volume. Various strengths of insulin are commonly available, with U-40 and U-100 being the most common. There are 100 units of insulin in 1 mL of U-100 insulin and 40 units in 1 mL of U-40. Insulin syringes are calibrated in units of insulin rather than in volume and are matched to either the U-40 or the U-100 strength. Pets are often prescribed U-40 insulin because of the smaller number of units required per injection.

Things You'll Need

• U-100 insulin syringe
• U-40 insulin
• Calculator

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Instructions

• 1

  Verify that you have U-40 insulin and a U-100 syringe. Insulin strength is clearly marked on the label, and U-100 syringes are noted on the barrel of the syringe.

• 2

  Determine the required dose of U-40 insulin. Example dose: 0.4 units per injection.

• 3

  Multiply the U-40 dose by 2.5. Example: 0.4 units of U-40 x 2.5 = 1 unit of U-40 in a syringe calibrated for U-100.

• 4

  Measure the equivalent amount into a U-100 syringe, and inject. Example: You must fill a U-100 syringe to the 1-unit mark to deliver 0.4 units of U-40 insulin.