How Many Units Is 5 mg of Tirzepatide?

For a 5 mg dose of compounded tirzepatide using a U-100 insulin syringe:

5 mg/mL vial: 100 units (1.0 mL — a full syringe) 10 mg/mL vial: 50 units (0.5 mL) 20 mg/mL vial: 25 units (0.25 mL) 30 mg/mL vial: approximately 16.7 units (0.167 mL) 60 mg/mL vial: approximately 8.3 units (0.083 mL)

The formula behind every calculation: units = (dose in mg / concentration in mg per mL) x 100. At 10 mg/mL, for example: (5 / 10) x 100 = 50 units.

In the standard tirzepatide escalation schedule, 5 mg is the second dose step. Patients begin at 2.5 mg weekly for four weeks, then increase to 5 mg for the next four weeks. For many patients, 5 mg is where appetite suppression and early weight loss become noticeably stronger.

The 5 mg dose is also a common long-term maintenance level for patients who respond well and do not need further escalation. Some providers keep patients at 5 mg if side effects are minimal and weight loss is progressing steadily, rather than escalating to 7.5 mg or higher.

In the SURMOUNT clinical trials, even the 5 mg dose group showed an average weight loss of approximately 15% of body weight over 72 weeks — a significant result that demonstrates the efficacy of this dose level.

Your compounding pharmacy determines the vial concentration, but understanding the tradeoffs helps you know what to expect.

At 5 mg/mL, a 5 mg dose fills an entire 1.0 mL syringe (100 units). This is the maximum volume a U-100 syringe can hold, and the large injection volume can be uncomfortable. Most pharmacies avoid dispensing this concentration for patients on 5 mg or higher doses.

At 10 mg/mL, a 5 mg dose is 50 units (0.5 mL). This is a comfortable injection volume and is the most common concentration for patients in the 2.5 mg to 10 mg dose range.

At 20 mg/mL, a 5 mg dose is only 25 units (0.25 mL). This small volume is easy to inject but slightly harder to draw precisely. Higher concentrations are typically reserved for patients on larger doses who need to minimize injection volume.

At 30 mg/mL, a 5 mg dose is approximately 16.7 units. This requires careful attention to the syringe markings since the unit count falls between whole numbers on most syringes.

Once you know your unit count, the injection process is the same regardless of concentration. Wash your hands and gather a new sterile U-100 insulin syringe, an alcohol swab, and your tirzepatide vial.

Clean the rubber stopper on the vial with the alcohol swab. Pull the syringe plunger back to draw air equal to the number of units you need. Insert the needle through the stopper and push the air into the vial. Invert the vial so the needle tip is submerged in the liquid, then slowly pull the plunger to your target unit mark.

Check for air bubbles. If you see any, tap the syringe barrel firmly to move bubbles to the top, then push the plunger slightly to expel them. Recheck the unit count and adjust if needed. Remove the needle from the vial and inject subcutaneously into the abdomen, thigh, or upper arm at a 90-degree angle.

Always check the concentration printed on your vial label before drawing. If your pharmacy changes your concentration between refills, your unit count for 5 mg will change even though the milligram dose stays the same. Using the old unit count with a new concentration will result in either too much or too little medication.

If your calculated unit count includes a decimal (like 16.7 units at 30 mg/mL), round to the nearest half-unit mark on your syringe. For a 16.7-unit dose, draw to the line between 16 and 17 units. If your syringe does not have half-unit markings, consult your pharmacy about whether to round up or down.

Never adjust your dose without your provider's approval. If 5 mg is producing significant side effects or insufficient results, discuss a dose change rather than modifying the unit count on your own.