Tirzepatide Reconstitution Calculator
Enter your tirzepatide vial size and bacteriostatic water amount to instantly calculate concentration, injection volume, and syringe units. Works for 5mg, 10mg, and 15mg vials.
Tirzepatide Dose Reference Table
Select your vial size to see pre-calculated injection volumes. All values use 2ml of bacteriostatic water per vial.
10mg vial + 2ml BAC water = 5000 mcg/ml
| Dose | Inject Volume (ml) | Syringe Units | Common Use |
|---|---|---|---|
| 2500 mcg (2.5 mg) | 0.50 ml | 50 units | Starting dose |
| 5000 mcg (5 mg) | 1.00 ml | 100 units | Maintenance dose |
| 7500 mcg (7.5 mg) | 1.50 ml | 150 units | Escalated dose |
| 10000 mcg (10 mg) | 2.00 ml | 200 units | Full vial dose |
| 12500 mcg (12.5 mg) | 2.50 ml | 250 units | High dose (split vials) |
| 15000 mcg (15 mg) | 3.00 ml | 300 units | Max research dose |
For a different BAC water amount, use the calculator above to get exact values for your reconstitution.
About Tirzepatide
Tirzepatide is a novel dual GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 receptor agonist. Unlike semaglutide, which acts only on GLP-1 receptors, tirzepatide activates both the GIP and GLP-1 pathways, producing synergistic effects on insulin secretion, glucagon suppression, and appetite reduction.
In clinical trials, tirzepatide produced average weight reductions of 15–22% of body weight over 72 weeks, outperforming semaglutide in head-to-head studies. The dual mechanism is believed to enhance fat cell metabolism more directly than GLP-1 alone, contributing to greater efficacy.
As a research peptide, tirzepatide comes most commonly in 5mg, 10mg, and 15mg lyophilized vials. The standard reconstitution is 2ml of bacteriostatic water per 10mg vial, yielding 5000 mcg/ml. Weekly subcutaneous injections are used, with dosing starting at 2500 mcg (2.5 mg) and titrating upward every 4 weeks as tolerated. The half-life is approximately 5 days, making weekly dosing appropriate for stable blood levels.
Common injection sites include the abdomen, outer thigh, or upper arm. Side effects during titration typically include nausea, reduced appetite, and mild gastrointestinal discomfort. These effects generally diminish after the first several weeks at each dose level. Slow titration is key to tolerability.
Frequently Asked Questions
The standard reconstitution for a 10mg tirzepatide vial is 2ml of bacteriostatic water, which yields a concentration of 5000 mcg/ml. This makes the math simple: a 2500 mcg dose requires 0.5ml (50 units on an insulin syringe). Some researchers use 4ml of BAC water with a 10mg vial to get 2500 mcg/ml, making injection volumes larger and easier to measure for smaller doses.
To reconstitute a 10mg tirzepatide vial: clean the rubber stopper with an alcohol swab, draw the desired amount of bacteriostatic water into a syringe, insert the needle at a slight angle into the vial, and slowly inject the water down the side of the vial — not directly onto the powder. Gently swirl the vial for 30–60 seconds. Do not shake. The solution should be clear and colorless. Store in the refrigerator immediately after reconstitution.
For a 30mg tirzepatide vial, use 6ml of bacteriostatic water to maintain the standard 5000 mcg/ml concentration. Alternatively, use 12ml for a 2500 mcg/ml concentration with larger, easier-to-measure injection volumes. The most important factor is consistency — choose a BAC water volume and stick with it so your doses remain accurate. Use the calculator above to compute exact injection volumes for your chosen concentration.
For subcutaneous tirzepatide injections, a 29–31 gauge, 4–8mm needle is ideal. Insulin syringes with a fixed needle are commonly used — 1ml capacity with 100-unit markings. Common injection sites include the abdomen (at least 2 inches from the navel), outer thigh, or upper arm. Rotate injection sites each week to avoid lipohypertrophy (fat buildup under the skin).
Tirzepatide reconstituted with bacteriostatic water is stable for up to 28 days when stored in the refrigerator at 2–8°C (36–46°F). Bacteriostatic water's preservative (benzyl alcohol) prevents microbial growth and extends shelf life. Always label your vial with the date of reconstitution and discard after 28 days. Never freeze reconstituted tirzepatide, as this can damage the peptide structure.