How to Reconstitute Tirzepatide
Research-grade tirzepatide arrives as a lyophilized (freeze-dried) powder, typically in 5mg, 10mg, or 15mg vials. Before it can be injected, you need to reconstitute it with bacteriostatic water. The process is straightforward, but the dose escalation protocol from 2.5mg to 15mg weekly makes your dilution choice critical.
Get this wrong and you're either injecting too much volume or struggling to measure tiny amounts on a syringe. This guide covers the full mixing process, dilution math for all three vial sizes, and proper storage.
What You Need
Before you start, gather everything:
- Tirzepatide lyophilized vial (5mg, 10mg, or 15mg)
- Bacteriostatic water (BAC water) -- not sterile water, not saline
- Insulin syringes -- 1mL (100 unit), 29-31 gauge
- Alcohol swabs -- for cleaning vial tops
- A clean, flat workspace
Why bacteriostatic water? It contains 0.9% benzyl alcohol that prevents bacteria from growing in your solution. Regular sterile water has no preservative, so the vial must be used within 24 hours. Since tirzepatide is dosed once weekly and a single vial can last weeks, BAC water is essential -- it gives you up to 28 days refrigerated.
Step-by-Step Reconstitution
Step 1: Clean Everything
Wipe the tops of both vials (tirzepatide and BAC water) with alcohol swabs. Let them air dry for 10 seconds. This prevents contamination.
Step 2: Draw Your Bacteriostatic Water
Using a fresh insulin syringe, draw your desired amount of BAC water. The amount you add determines your concentration (see the dilution charts below).
For a 10mg vial, 2mL is the sweet spot. It gives you 5,000mcg/mL -- clean numbers across the entire dose escalation from 2.5mg through 15mg.
Step 3: Add Water to the Peptide Vial
Insert the needle into the tirzepatide vial at an angle, aiming at the glass wall -- not directly at the powder. Let the water trickle down the side of the vial gently.
Do not squirt water directly onto the powder. Tirzepatide is a 39-amino-acid peptide with a C20 fatty diacid chain. Aggressive mixing can damage the molecular structure and reduce potency. Spray the water down the inside wall and let it flow onto the powder naturally.
Step 4: Let It Dissolve
Gently swirl the vial with a slow rotating motion. Do not shake it. The powder should dissolve within 1-2 minutes into a perfectly clear, colorless solution.
If particles remain after 5 minutes of gentle swirling, the peptide may be degraded. A properly manufactured tirzepatide dissolves easily.
Step 5: Store Correctly
Refrigerate immediately at 36-46F (2-8C). The reconstituted solution is stable for up to 28 days with bacteriostatic water.
Dilution Charts
Why 2mL for a 10mg vial? It keeps every dose in the standard escalation protocol measurable on a standard insulin syringe. At 2mL in a 10mg vial, a 2.5mg starting dose is exactly 50 units and a 5mg dose is exactly 100 units -- no awkward fractions.
Syringe Math
Here's the formula for any vial size and any amount of water:
Concentration = Peptide Amount (mcg) / Water Added (mL)
Then to find your injection volume:
Units to inject = Desired Dose (mcg) / Concentration (mcg/mL) x 100
Example: 10,000mcg vial + 2mL water = 5,000mcg/mL. For a 2.5mg (2,500mcg) dose: 2,500 / 5,000 x 100 = 50 units.
For a 5mg dose: 5,000 / 5,000 x 100 = 100 units -- the full syringe.
Doses Per Vial
5mg vial:
- At 2.5mg/week = 2 weeks
- At 5mg/week = 1 week
10mg vial:
- At 2.5mg/week = 4 weeks
- At 5mg/week = 2 weeks
- At 7.5mg/week = 1.3 weeks
- At 10mg/week = 1 week
15mg vial:
- At 2.5mg/week = 6 weeks
- At 5mg/week = 3 weeks
- At 10mg/week = 1.5 weeks
- At 15mg/week = 1 week
A 10mg vial covers the first month of a standard escalation at 2.5mg/week. At maintenance doses of 10-15mg, plan on one vial per week.
Don't want to do math? Use our Reconstitution Calculator -- plug in your vial size, water amount, and desired dose, and it does the rest.
