Compounded Tirzepatide: Calculator, Pharmacies & Reconstitution Math
The complete guide to compounded tirzepatide — what it is, the legal status, the reconstitution calculator, the BAC water math, and how to choose a legitimate compounding pharmacy.
01 Reconstitution calculator
Compounded tirzepatide arrives as a sterile lyophilized powder in a sealed vial. You add bacteriostatic water before the first use. The amount of BAC water determines the final concentration, which determines how many units you draw on a U-100 syringe per dose. Use the calculator below to do the math.
Tirzepatide Reconstitution Calculator
Tool · 2 of 3For compounded tirzepatide vials. Enter your vial size, BAC water volume, and target dose — get the exact units to draw on a U-100 syringe.
- Concentration
- 5 mg/mL
- Draw on U-100
- 50 units
- Volume per dose
- 0.50 mL
- Doses per vial
- 4
*For informational purposes only. Compounded tirzepatide is not FDA-approved. Always follow your compounding pharmacy's reconstitution instructions and your prescriber's guidance.
02 What is compounded tirzepatide?
Compounded tirzepatide is a customized version of the same molecule that is sold as Mounjaro and Zepbound, prepared by a state-licensed compounding pharmacy under USP <797> sterile compounding standards. Compounders source the tirzepatide active pharmaceutical ingredient (API), prepare it as a sterile lyophilized powder in single- or multi-dose vials, and dispense it to individual patients with a valid prescription.
The active ingredient — tirzepatide — is identical regardless of producer. What differs is the regulatory pathway: Mounjaro and Zepbound are produced by Eli Lilly under full FDA approval with phase 3 trials and ongoing post-marketing surveillance. Compounded tirzepatide is produced under section 503A or 503B of the FD&C Act, which has a different (and less stringent) approval mechanism designed for medications customized to individual patient needs.
03 Is compounded tirzepatide legal? FDA regulatory status
Compounded tirzepatide is legal but not FDA-approved — those are two different things. Here's the regulatory framework:
Section 503A (traditional compounding)
Allows state-licensed pharmacies to prepare individualized prescriptions for specific patients in response to a valid prescription. There must be a documented patient-prescriber-pharmacy relationship. This is the pathway most telehealth tirzepatide providers use. It is legal regardless of FDA shortage status.
Section 503B (outsourcing facilities)
Allows larger "outsourcing facilities" to compound in bulk without individual prescriptions for use by clinics and hospitals. 503B facilities are FDA-registered and follow stricter cGMP standards. Bulk compounding of tirzepatide under 503B is more restricted now that the brand is off the shortage list.
The 2024–2026 shortage timeline
From late 2022 through October 2024, tirzepatide was on the official FDA drug shortage list, which expanded the conditions under which it could be compounded (including by 503B facilities). The FDA officially declared the shortage resolved in October 2024. After a transition period and several court actions, compounding continues under 503A for individual prescriptions, while 503B mass compounding has been more restricted. The legal environment remains in flux — see our news page for current developments.
As of April 2026, compounded tirzepatide remains legally available through licensed telehealth providers and state-licensed compounding pharmacies for individual patients with valid prescriptions. It is not FDA-approved. The cost difference vs brand pricing is roughly 70–85%.
04 BAC water explained (don't use sterile water)
BAC water = bacteriostatic water. It's sterile water with a 0.9% benzyl alcohol preservative added. The benzyl alcohol prevents bacterial growth, which is why BAC water is used for multi-dose vial reconstitution — you'll be inserting a needle into the vial multiple times over several weeks, and the preservative protects sterility between draws.
Sterile water for injection (SWFI) is also sterile — but it has no preservative. SWFI is intended for single-use only. Reconstituting tirzepatide with SWFI in a multi-dose vial creates a contamination risk after the first puncture.
Always reconstitute multi-dose tirzepatide vials with BAC water, not SWFI. Most compounding pharmacies will ship the appropriate water with the vial. If you need to purchase separately, BAC water is available from medical suppliers in 30 mL vials.
BAC water for different vial sizes
| Vial mg | BAC water | Final concentration | Units / mg (U-100) |
|---|---|---|---|
| 10 mg | 1 mL | 10.0 mg/mL | 10 |
| 10 mg | 2 mL | 5.0 mg/mL | 20 |
| 15 mg | 1.5 mL | 10.0 mg/mL | 10 |
| 15 mg | 3 mL | 5.0 mg/mL | 20 |
| 20 mg | 2 mL | 10.0 mg/mL | 10 |
| 30 mg | 2 mL | 15.0 mg/mL | 6.67 |
| 30 mg | 3 mL | 10.0 mg/mL | 10 |
05 Step-by-step reconstitution
The procedure is straightforward but must be sterile. Allow 5 minutes the first time you do it. After that it takes 90 seconds.
- Wash hands thoroughly with soap and water for 20 seconds. Dry on a clean towel.
- Disinfect the workspace. Wipe a flat surface with a fresh alcohol pad and let it air-dry.
- Inspect the vial. The lyophilized tirzepatide should appear as a uniform white or off-white cake or powder. No discoloration, no particulates, no signs of moisture.
- Wipe the rubber stoppers. Wipe the top of both the tirzepatide vial and the BAC water vial with fresh alcohol pads. Let air-dry for 10 seconds.
- Draw the BAC water. Using a sterile syringe (typically a 3 mL syringe with a needle), draw the prescribed volume of BAC water (e.g., 2 mL).
- Inject the BAC water slowly into the tirzepatide vial. Insert the needle through the rubber stopper at a slight angle. Direct the stream against the inner glass wall — do not shoot it directly into the powder. This minimizes foaming.
- Swirl gently. Roll the vial between your hands or swirl it in a small circle on the table. Do NOT shake — shaking damages the peptide structure.
- Wait until clear. Within 1–2 minutes the powder fully dissolves into a clear, colorless solution.
- Label the vial with the reconstitution date and the beyond-use date (BUD) printed on your prescription.
- Refrigerate at 36–46°F (2–8°C). Store upright. Do not freeze.
06 Storage and shelf life
| Storage condition | Compounded vial | Brand vial (Lilly) |
|---|---|---|
| Refrigerated (unopened) | 28–60 days BUD | Until expiration date |
| Refrigerated (after first use) | Per BUD on label | 21 days for pen |
| Room temp (≤86°F) | Brief periods only | Up to 21 days for pen, 21 days for vial |
| Frozen | Discard if frozen | Discard if frozen |
| Above 86°F / 30°C | Discard | Discard |
The single most common storage mistake is leaving the vial in a hot car or mailbox. If your shipment arrives warm, contact the provider before using. Reputable telehealth providers will replace heat-damaged shipments at no cost.
07 Compounded combinations: B12, glycine, niacinamide, pyridoxine
Some compounding pharmacies offer "tirzepatide plus" formulations with additional ingredients added to the vial. These are marketed as offering anti-nausea, energy, or wellness benefits. The clinical evidence is mixed, but the side-effect profiles are generally favorable.
| Additive | Common dose | Claimed benefit | Evidence |
|---|---|---|---|
| Vitamin B12 (cyanocobalamin) | 0.5–1 mg/mL | Energy, fatigue support | Modest — useful if low |
| Pyridoxine (B6) | 5–10 mg/mL | Anti-nausea | Moderate (used in pregnancy nausea) |
| Niacinamide (B3) | 5 mg/mL | Skin health, anti-flush | Limited GLP-1-specific data |
| Glycine | 1–2 mg/mL | Sleep, GI support | Limited |
These combinations cost slightly more than plain tirzepatide ($20–$50 add-on at most providers) and typically use the same dosing schedule. They are not a substitute for actual nutritional or anti-emetic management — but they're not harmful either, and they may offer marginal benefit for the right patient.
08 The major US compounding pharmacies
You typically don't choose your compounding pharmacy directly — your telehealth provider routes the prescription to its partner pharmacy. The major players in the GLP-1 compounding space include:
- Empower Pharmacy — Houston-based, large-scale 503A and 503B-compliant compounder. Used by many telehealth providers.
- Strive Pharmacy — Phoenix-based 503A compounder serving telehealth providers nationally.
- Hallandale Pharmacy — Florida-based 503A compounder with a focus on telehealth GLP-1 supply.
- Olympia Pharmacy — Florida-based, multi-state 503A compounder.
- Belmar Pharmacy — Colorado-based long-standing compounder.
If you want to verify the source pharmacy for your specific provider, simply ask them in your intake or first message. Reputable providers will name their partner pharmacy.
Compounded tirzepatide, $199/month.
Skip the brand-name retail markup. Get the same molecule, prepared by a state-licensed compounding pharmacy, shipped cold to your door.
See Compounded Options→09 Compounded tirzepatide FAQ
Compounded tirzepatide is legal in the United States under sections 503A and 503B of the Federal Food, Drug, and Cosmetic Act. State-licensed compounding pharmacies may prepare medications for individual patients with valid prescriptions. Compounded tirzepatide is not FDA-approved, but it is also not illegal — these are different regulatory categories. The FDA has issued guidance about compounded GLP-1 medications and the regulatory landscape continues to evolve.
The active ingredient is the same — tirzepatide is tirzepatide, regardless of the manufacturer. The difference is in the regulatory pathway: Mounjaro/Zepbound are produced by Eli Lilly under FDA approval with full clinical trials. Compounded tirzepatide is produced by USP <797>-compliant pharmacies that source the active pharmaceutical ingredient and prepare it for individual prescriptions. Quality standards differ; the molecule does not.
The FDA temporarily allowed expanded compounding of GLP-1 medications during the 2022–2024 brand-name shortages. Tirzepatide was officially removed from the FDA shortage list in October 2024, which restricts the conditions under which it can be compounded. As of April 2026, compounding under section 503A (individual prescription) remains legal under most circumstances; mass compounding under 503B is more restricted. The legal landscape continues to evolve — check our news page for the latest.
It depends on the concentration your prescriber wants. The two most common conventions: 2 mL of BAC water for a 5 mg/mL final concentration (good for 2.5–10 mg dosing), or 1 mL of BAC water for a 10 mg/mL final concentration (good for 5–15 mg dosing). Your compounding pharmacy will print the specific instructions on the vial.
Most commonly 2 mL of BAC water for a 15 mg/mL concentration (compact draws, suitable for 5–15 mg per dose). Some prescribers prefer 3 mL for 10 mg/mL (larger draws, easier to measure precisely at lower doses). Always follow the specific instructions provided with your prescription.
Most compounding pharmacies assign a beyond-use date (BUD) of 28 days after reconstitution when stored at 36–46°F (2–8°C). Some pharmacies use 60 days based on stability testing. Brand-name vials (Lilly) are stable for 21 days at room temperature once opened. Always follow the date printed on your vial — do not extend beyond the BUD.
For brief periods (a few hours during travel or shipping), compounded tirzepatide tolerates room temperature without meaningful degradation. The FDA brand-name labeling permits up to 21 days at room temperature (≤86°F / 30°C) after first use. Avoid extreme heat (above 86°F) and never freeze. If a shipment arrives warm, photograph it and contact the provider before injecting.
Some compounders add vitamin B12 (cyanocobalamin) or pyridoxine (vitamin B6) to the tirzepatide vial. B12 is added for energy/fatigue support — many GLP-1 patients become functionally B12-deficient as they eat less. Pyridoxine is added because it has anti-nausea properties and is the active ingredient in many morning-sickness medications. Whether these add-ons provide meaningful clinical benefit is debated; the side-effect profile is generally favorable.
Yes — Empower Pharmacy and Strive Pharmacy are two of the larger, state-licensed compounding pharmacies in the US that produce compounded tirzepatide. Both have published policies about sourcing, sterility, and beyond-use dating. Many telehealth providers use one of these (or similar) pharmacies as their dispensing partner. You can usually verify which pharmacy your provider uses by asking them directly.
No. Compounding pharmacies in the United States can only dispense compounded medications with a valid prescription from a licensed prescriber. Anyone selling "tirzepatide" without requiring a prescription is operating outside the legal compounding pathway — this is typically gray-market peptide labeled "research only," and it should not be injected into humans.
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