How to Mix Semaglutide
Reconstitution Guide: BAC Water Ratios & Dosing Chart
Always consult a healthcare professional before starting any injection protocol.
Why Reconstitution Matters
Semaglutide is supplied as a freeze-dried (lyophilised) powder. It must be reconstituted with bacteriostatic water (BAC water) before it can be injected. Using the wrong volume of BAC water changes the concentration of your solution, which means your unit dose on the syringe will no longer match the intended mg dose. Always double-check your vial size against the ratios below.
📊 Reconstitution Ratios
| Vial Size | BAC Water Added | Final Concentration |
|---|---|---|
| 5mg vial | 2.0ml | 2.5mg/ml (25 units = 0.25mg) |
| 10mg vial | 2.0ml | 5mg/ml (10 units = 0.50mg) |
🧪 Step-by-Step Mixing Instructions
Wash your hands
Wash thoroughly with soap and water for at least 20 seconds and dry with a clean towel.
Swab both vial tops
Clean the rubber stopper on your Semaglutide vial and your BAC water vial with a fresh alcohol swab each. Let air-dry for 10 seconds.
Draw 2.0ml of BAC water
Using a syringe, draw exactly 2.0ml of bacteriostatic water from its vial — this applies to both the 5mg and 10mg vial sizes.
Inject slowly down the vial wall
Angle the needle so the water runs down the inside of the glass onto the powder — do not squirt it directly onto the powder.
Check the solution is clear
It should be clear and colourless with no particles. Discard if cloudy or discoloured.
Label and refrigerate
Write the mixing date on the vial. Store at 2–8°C and use within 28 days.
📅 Dose to Unit Conversion (5mg vial)
| Dose | Units (U-100) | Volume |
|---|---|---|
| 0.25mg | 10 Units | 0.10ml |
| 0.50mg | 20 Units | 0.20ml |
| 1.00mg | 40 Units | 0.40ml |
| 1.70mg | 68 Units | 0.68ml |
| 2.40mg | 96 Units | 0.96ml |
Semaglutide Mixing FAQs
How much BAC water do I add to a Semaglutide vial?
Add 2.0ml of bacteriostatic water to both 5mg and 10mg vials. This gives a 2.5mg/ml concentration for the 5mg vial and a 5mg/ml concentration for the 10mg vial — the unit doses differ between the two, so always check which vial size you have.
Can I use sterile water instead of BAC water?
No. Sterile water has no preservative, so the solution must be used within a few hours and cannot be stored. Bacteriostatic water contains 0.9% benzyl alcohol, allowing safe fridge storage for up to 28 days.
Why is my Semaglutide solution cloudy after mixing?
A cloudy or discoloured solution suggests the peptide has degraded or was shaken too vigorously. Do not inject it — dispose of the vial safely and use a fresh one, mixing gently next time.
How long does mixed Semaglutide last?
Once reconstituted, store in the fridge at 2–8°C and use within 28 days. Label the vial with the mixing date so you don't lose track.