MyPeptideMatchSemaglutide Reconstitution Calculator
Calculate the exact insulin syringe units for your compounded semaglutide dose. Enter your vial size, the amount of bacteriostatic water you added, and your weekly dose to get an instant, precise reading.
Also called: semaglutide calculatorsemaglutide units calculatorsemaglutide dosage calculator
Semaglutide dosage chart — mg to syringe units
Use this chart to look up your semaglutide dose in the left column and find the corresponding insulin syringe units based on your reconstitution concentration. All values use a standard U-100 (1 mL) insulin syringe.
| Dose | 2.5 mg/mL5 mg + 2 mL | 5 mg/mL5 mg + 1 mL | 2 mg/mL5 mg + 2.5 mL | Typical Use |
|---|---|---|---|---|
| 0.25 mg | 10 units | 5 units | 12.5 units | Typical starting dose (weeks 1–4) |
| 0.5 mg | 20 units | 10 units | 25 units | Standard dose (weeks 5–8) |
| 1 mg | 40 units | 20 units | 50 units | Maintenance dose |
| 1.7 mg | 68 units | 34 units | 85 units | Higher maintenance |
| 2 mg | 80 units | 40 units | 100 units | Maximum compounded dose (common) |
| 2.4 mg | 96 units | 48 units | 120 units* | FDA-approved Wegovy max dose |
* Values exceeding 100 units require a 1 mL syringe and two injections may be needed for doses above 1 mL. Always follow your prescribing clinician's specific protocol.
Dosing Calculation Example: Semaglutide 0.25 mg starting dose
Here is how the math works for the most common semaglutide starting setup.
You have a 5 mg vial of compounded semaglutide and add 2 mL of bacteriostatic water. Your starting dose is 0.25 mg (250 mcg) weekly using a 1 mL (100-unit) insulin syringe.
- Concentration: 5 mg ÷ 2 mL = 2.5 mg/mL
- Dose volume: 250 mcg ÷ 2,500 mcg/mL = 0.1 mL
- Syringe units: 0.1 mL × 100 = 10 units
- Doses per vial: 5,000 mcg ÷ 250 mcg = 20 weekly doses (≈5 months)
How to reconstitute compounded semaglutide
Compounded semaglutide is supplied as lyophilized (freeze-dried) powder and must be mixed with bacteriostatic water before use. Follow your prescribing clinician's specific instructions — the steps below are a general guide.
Gather supplies
Semaglutide vial (lyophilized powder), bacteriostatic water (BAC water), sterile U-100 insulin syringes, 70% isopropyl alcohol swabs, and a sharps container.
Bring vials to room temperature
Allow both the semaglutide vial and the bacteriostatic water to sit at room temperature for 15–30 minutes before mixing. Cold-to-cold mixing increases the risk of foaming.
Swab and inject BAC water slowly
Swab both rubber stoppers with a fresh alcohol swab. Draw the correct BAC water volume and inject it slowly into the semaglutide vial, aiming the stream along the inner glass wall at a 45° angle — not directly at the powder.
Gently swirl until clear
Slowly rotate or swirl the vial until the solution is completely clear. Do not shake. Semaglutide may take several minutes to fully dissolve. A cloudy or particulate solution should not be used.
Label and refrigerate
Mark the vial with the reconstitution date. Store at 2–8°C (36–46°F). Reconstituted semaglutide with bacteriostatic water is typically stable for 3–4 weeks refrigerated — follow your pharmacy's specific guidance.
For a complete reconstitution guide covering all peptides, sterile technique, and common mistakes, read how to reconstitute peptides.
Frequently asked questions
Common questions about semaglutide reconstitution, dosage calculations, and syringe units.
How many units is 0.25 mg of semaglutide?
It depends on your concentration. At 2.5 mg/mL (5 mg vial + 2 mL BAC water): 0.25 mg = 0.1 mL = 10 units on a U-100 syringe. At 2 mg/mL (5 mg vial + 2.5 mL): 0.25 mg = 0.125 mL ≈ 12.5 units. Use the calculator above to get the exact units for your specific setup.
How much bacteriostatic water do I add to a 5 mg semaglutide vial?
The most common setup is 2 mL of bacteriostatic water into a 5 mg semaglutide vial, yielding a 2.5 mg/mL concentration. This is recommended because the starting dose (0.25 mg/week) equals a clean 10 units on a U-100 syringe, making measurement easy and accurate. Some protocols use 1 mL (5 mg/mL) for a more concentrated solution with a smaller injection volume.
How many units is 0.5 mg of semaglutide?
At 2.5 mg/mL concentration: 0.5 mg = 0.2 mL = 20 units on a U-100 syringe. At 2 mg/mL: 0.5 mg = 0.25 mL = 25 units. The semaglutide reconstitution calculator above will give you the exact reading for your specific vial and water setup.
How many units is 1 mg of semaglutide?
At 2.5 mg/mL (5 mg vial + 2 mL BAC water): 1 mg = 0.4 mL = 40 units. At 5 mg/mL (5 mg vial + 1 mL BAC water): 1 mg = 0.2 mL = 20 units. Use the calculator to find your exact number.
How many units is 2 mg of semaglutide?
At 2.5 mg/mL concentration: 2 mg = 0.8 mL = 80 units. At 5 mg/mL: 2 mg = 0.4 mL = 40 units. Note: if you're on a 2 mg dose at 2.5 mg/mL, you'll need a 1 mL syringe to fit the full 80 units.
How do I reconstitute a 10 mg semaglutide vial?
For a 10 mg semaglutide vial, a common setup is 2 mL of BAC water (yielding 5 mg/mL) or 4 mL (yielding 2.5 mg/mL). At 5 mg/mL, a 0.25 mg starting dose = 0.05 mL = 5 units. At 2.5 mg/mL, 0.25 mg = 10 units. Select your vial size and water volume in the calculator above for your exact reading.
How long does reconstituted semaglutide last?
Compounded semaglutide reconstituted with bacteriostatic water is typically stable for 3–4 weeks when stored refrigerated at 2–8°C (36–46°F). Freeze aliquots at -20°C for longer storage (up to 3 months). Always follow your compounding pharmacy's specific stability guidance, which takes precedence over general estimates.
What concentration should I use for semaglutide?
There is no single correct concentration — it depends on your dose and your prescriber's instructions. The most common starting setup is 2 mL BAC water into a 5 mg vial (2.5 mg/mL) because the starting dose of 0.25 mg equals exactly 10 units on a U-100 syringe, which is easy to measure accurately. Your compounding pharmacy may also prepare pre-mixed vials at a specified concentration.
What needle should I use to inject semaglutide?
Most semaglutide injections are administered subcutaneously using a 29G or 31G insulin syringe with a ½-inch needle. Common injection sites include the lower abdomen, thigh, or upper arm. Always rotate injection sites and follow your prescriber's specific instructions.
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Medical Disclaimer: This semaglutide reconstitution calculator is provided for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. All dosing should be determined and supervised by a licensed healthcare provider. The dosing references on this page are general guidelines and may not be appropriate for your individual circumstances. Compounded semaglutide is not equivalent to FDA-approved brand-name semaglutide products. Always consult your prescriber.