How to Reconstitute Tirzepatide
Reconstituting Tirzepatidemeans adding bacteriostatic water to the freeze-dried (lyophilized) powder so you can inject a measured dose. If you've just received a vial with a small disc of powder at the bottom, this is where you start.
- Clean the vial stopper with an alcohol swab. Let it dry completely.
- Draw bacteriostatic water into a syringe. We recommend 2 mL for most peptides. Most vials hold 3 mL or less.
- Inject the water slowly into the vial, aiming at the glass wall — not directly onto the powder. This prevents damaging the peptide.
- Gently swirl the vial until the powder is fully dissolved. Do not shake.
- Store in the refrigerator. Most reconstituted peptides last 4–6 weeks refrigerated.
After reconstitution, your vial won't be completely full — that's normal. A typical vial holds about 3 mL, and you're adding 1–3 mL of water. The dose is based on concentration, not how full the vial looks.
How to Draw a Dose
Drawing liquid from a sealed vial requires injecting air first. This equalizes the pressure inside the vial so the liquid flows smoothly into the syringe.
- Clean the vial stopper with a fresh alcohol swab.
- Pull back the plunger to draw air into the syringe — the same volume you plan to withdraw (e.g., if you need 20 units of liquid, draw 20 units of air).
- Insert the needle through the vial stopper and push the plunger to inject the air into the vial.
- Invert the vial so the stopper faces down, with the needle tip submerged in the liquid.
- Pull back the plunger slowly to your target unit mark.
- Check for air bubbles. If you see any, gently flick the barrel to move them toward the needle, then push the plunger slightly to force them back into the vial. Readjust to your target volume.
- Remove the needle from the vial. You're ready to inject.
Tirzepatide Dosing Schedule for Weight Loss
Tirzepatide is a dual GLP-1/GIP receptor agonist used for weight management and type 2 diabetes. It's injected subcutaneously once per week. The dose is gradually increased every 4 weeks to minimize side effects:
| Weeks | Weekly Dose | Phase |
|---|---|---|
| 1–4 | 2.5 mg | Initiation |
| 5–8 | 5 mg | Titration |
| 9–12 | 7.5 mg | Titration |
| 13–16 | 10 mg | Titration |
| 17–20 | 12.5 mg | Titration |
| 21+ | 15 mg | Maintenance |
Many people find an effective dose between 5 mg and 10 mg without needing to reach the maximum. If side effects are significant, stay at the current dose for an extra 4 weeks before increasing.
How Many Units Is 2.5 mg of Tirzepatide?
This is the most common tirzepatide dosing question. The answer depends entirely on your concentration — which is determined by how much water you added to your vial.
| Vial | Water | Concentration | Units for 2.5 mg |
|---|---|---|---|
| 10 mg | 1 mL | 10 mg/mL | 25 units |
| 10 mg | 2 mL | 5 mg/mL | 50 units |
| 30 mg | 2 mL | 15 mg/mL | 17 units |
| 60 mg | 2 mL | 30 mg/mL | 8 units |
Understanding Peptide Dosing
The key concept is concentration. When you add 2 mL of water to a 10 mg vial, you get a concentration of 5 mg/mL. To dose 2.5 mg, you need 0.5 mL — which is 50 units on a standard insulin syringe.
Insulin syringes are marked in "units," where 100 units = 1 mL. So the math is simple: multiply the volume in mL by 100 to get your unit mark. The calculator above does this for you automatically.
Frequently Asked Questions
How many mg is 20 units of tirzepatide?
20 units = 0.2 mL. If your concentration is 5 mg/mL, then 0.2 mL × 5 = 1 mg. If your concentration is 10 mg/mL, then 0.2 mL × 10 = 2 mg. Use the calculator above for your exact setup.
What is the starting dose of compounded tirzepatide?
The standard starting dose is 2.5 mg per week for 4 weeks. This matches the FDA-approved Mounjaro/Zepbound titration schedule. Starting low helps minimize nausea and GI side effects.
How long does reconstituted tirzepatide last?
When mixed with bacteriostatic water and refrigerated, reconstituted tirzepatide typically lasts 4–6 weeks. Keep the vial upright and away from light.