Tirzepatide Reconstitution Calculator & Dosing Guide
Everything you need to reconstitute and dose compounded tirzepatide — vial ratios, syringe markings, the full titration ladder, and storage guidance. Updated for 2026.
Open the Calculator Pre-Loaded for Tirzepatide
Pick your vial size and dose — get exact syringe markings instantly.
Open Calculator →What Is Tirzepatide?
Tirzepatide is a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist. The FDA approved it under the brand name Mounjaro (type 2 diabetes, 2022) and Zepbound (chronic weight management, 2023). Clinical trials reported average weight loss of ~20% of body weight at the 15 mg dose over 72 weeks.
Brand-name tirzepatide ships as single-use prefilled auto-injector pens. Compounded tirzepatide — dispensed by 503A pharmacies via telehealth providers like Hims, Ro, and Mochi — typically arrives as a lyophilized (freeze-dried) powder in a glass vial, requiring reconstitution with bacteriostatic water before the first dose.
Common Reconstitution Ratios
Your vial size and BAC water amount determine concentration. Here are the ratios used most often for compounded tirzepatide:
| Vial size | BAC water | Concentration | 5 mg draw (U100) | 10 mg draw (U100) |
|---|---|---|---|---|
| 10 mg | 1 ml | 10 mg/ml | 50 units | 100 units |
| 10 mg | 2 ml | 5 mg/ml | 100 units | exceeds 1ml |
| 15 mg | 1.5 ml | 10 mg/ml | 50 units | 100 units |
| 30 mg | 3 ml | 10 mg/ml | 50 units | 100 units |
| 30 mg | 2 ml | 15 mg/ml | 33 units | 67 units |
A 10 mg/ml concentration is popular because it keeps every titration step inside a single U100 syringe capacity. For doses above 10 mg on a 10 mg/ml vial, either reconstitute more concentrated (15 mg/ml on a 30 mg vial) or split into two draws.
Tirzepatide Titration Schedule
Eli Lilly's approved titration for Mounjaro and Zepbound steps up every 4 weeks:
| Week | Dose | Purpose |
|---|---|---|
| 1–4 | 2.5 mg | Starting / tolerance phase. No therapeutic weight-loss expectation. |
| 5–8 | 5 mg | First therapeutic dose. Some users stop here. |
| 9–12 | 7.5 mg | Intermediate step. |
| 13–16 | 10 mg | Common maintenance dose. |
| 17–20 | 12.5 mg | Escalation step. |
| 21+ | 15 mg | Maximum approved dose. |
Real-world users frequently hold at a step longer than 4 weeks to manage GI side effects (nausea, constipation, reflux) or to stretch supply. Never increase faster than the manufacturer schedule; consult your prescriber for any deviation.
Storage and Handling
- Pre-reconstitution: Freezer-stable long term. Room-temperature-stable for typical shipping windows.
- Post-reconstitution: Refrigerate at 36–46°F (2–8°C). Stable ~28 days in BAC water; some users report longer but 28 days is the conservative window.
- Avoid freeze-thaw cycles. Each cycle degrades peptide integrity.
- Protect from light. Original amber or opaque vials ideal; otherwise store in a dark box in the fridge.
- Discard immediately if solution becomes cloudy, yellow, or shows particulates.
Frequently Asked Questions
How do I reconstitute compounded tirzepatide?
Most compounded vials arrive as 10 mg, 15 mg, or 30 mg of lyophilized powder. Add 2 ml of BAC water to a 10 mg vial for a 5 mg/ml concentration, or 3 ml to a 30 mg vial for 10 mg/ml. Our calculator does the math for any vial + water combination.
What syringe size do I need for tirzepatide?
Most users inject with a 1 ml U100 insulin syringe. Titration doses (2.5–5 mg) land in the 25–50 unit range; higher doses near 15 mg can approach 100 units. If your draw would exceed 1 ml, either split into two injections or reconstitute to a higher concentration.
What is the standard tirzepatide titration schedule?
2.5 mg for 4 weeks, then step up by 2.5 mg every 4 weeks: 5 → 7.5 → 10 → 12.5 → 15 mg. Many users stay at a step longer to manage side effects or stretch supply. Follow your prescriber's guidance.
How long does reconstituted tirzepatide last?
Approximately 28 days refrigerated in BAC water. Discard if cloudy, discolored, or past 28 days.
Is compounded tirzepatide the same as Mounjaro or Zepbound?
Same active molecule, different delivery. Brand products ship as single-use prefilled pens with FDA-approved labeling. Compounded tirzepatide is a lyophilized vial dispensed by 503A pharmacies. Active ingredient identical; inactive ingredients, presentation, and regulatory status differ.
Where do I inject tirzepatide?
Subcutaneous injection — abdomen (2 inches from navel in any direction), upper outer thigh, or back of upper arm. Rotate sites weekly to minimize irritation. The Stackr app tracks injection site rotation for you.
Track Your Tirzepatide Protocol in Stackr
Log weekly doses, track side effects, rotate injection sites, and get reorder reminders.
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Stackr is a personal supply and protocol tracking tool. Nothing on this page is medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional before starting, changing, or stopping any medication or protocol. Do not self-medicate. Compounded tirzepatide availability and legality vary by jurisdiction and change over time.