GLP-1 Powder Reconstitution Supplies and Safety Checks
Guide scope: Most injectable GLP-1 products are supplied ready to inject. If you have written reconstitution instructions for a GLP-1 powder product, this guide covers supplies, step-by-step handling, and one critical safety check: matching the final concentration to the dose volume your prescriber or pharmacy gives you.
Australian note: Australian supply of compounded GLP-1 receptor agonist products such as semaglutide and tirzepatide is restricted. TGA guidance states that GLP-1 receptor agonist analogues are generally not covered by compounding exemptions, and TGA material on the 2024 GLP-1 compounding changes says compounding GLP-1 receptor agonists was no longer permitted from 1 October 2024. Confirm your product and supply pathway directly with your prescriber or pharmacy before using any vial-supplied GLP-1 product.
The quick answer
| Step | What you use |
|---|---|
| Add the liquid to the powder | The diluent supplied or specified in writing by your prescriber or pharmacy, drawn with a sterile syringe sized to the prescribed volume and an appropriate sterile drawing-up needle |
| Draw and inject each dose | For many small subcutaneous dose volumes, a 0.5mL U-100 insulin syringe (31G, 6mm) may be suitable if your prescriber or pharmacy has instructed syringe dosing; use the device and needle size they specify |
| Keep it clean | An alcohol wipe on every stopper, every time |
| Finish safely | A 0.6L Sharpsafe container |
The dose-vs-concentration check (read this first). GLP-1 products are not all the same strength, and a "0.25mg dose" can be a completely different volume between two products. Work out how many millilitres - or units - your dose is for your vial's concentration, and get that figure from your prescriber or supplying pharmacy in writing before you draw the first dose. Do not copy a units number from a pen or from someone else's vial. Mismatched concentration is a well-documented cause of accidental GLP-1 overdose.
Does yours even need reconstituting?
Only if it arrives as a dry powder or cake in the vial with written reconstitution instructions from the prescriber or pharmacy. If your written instructions say the product is already a liquid, do not reconstitute it; follow the written instructions from your prescriber or pharmacy, or see our GLP-1 needle and syringe size guide for supply sizing. Reconstituting only applies to the powder form, where you add the exact diluent and volume your pharmacy specifies.
How much water to add
The labelled final volume or final concentration sets how many units equal your prescribed dose. Use the pharmacy's stated final volume or concentration; do not calculate from the added diluent volume unless the written instructions explicitly say the added volume and final volume are the same.
For example, if your written product instructions say a 10mg vial has a final volume of 2mL, the concentration is 5mg/mL. A prescribed 0.25mg dose from that concentration is 0.05mL, which is 5 units on a U-100 insulin syringe (units = mL x 100 only on U-100 syringes). Add only the specified diluent and volume - do not pick your own volume, because it changes every dose you draw afterwards. Our guide to reading an insulin syringe has the full mL-to-units conversion table.
Step by step
- Wash your hands. Set out the powder vial, the supplied or specified diluent, your sterile transfer syringe and needle, enough fresh alcohol wipes for each vial stopper or puncture, and your sharps container.
- Use a separate fresh alcohol wipe for each vial stopper, scrub each stopper, and let it air-dry before puncturing.
- Draw the prescribed volume of the supplied or specified diluent into a sterile syringe sized for that volume. Pull back the same volume of air first and inject it into the diluent vial only if your pharmacy instructions tell you to do this.
- Insert the needle into the powder vial and aim the stream of diluent down the inside wall of the glass - not straight onto the powder. A gentle stream reduces foaming and agitation.
- Withdraw the needle. Swirl gently - or let it sit - until the powder fully dissolves and the appearance matches the written instructions. Do not shake unless your pharmacy instructions say to; shaking can cause foaming and unnecessary agitation.
- Once fully dissolved and only if the vial was mixed exactly as instructed, continue to follow the pharmacy's written directions. Appearance does not confirm sterility or correct concentration. Label it with the date you mixed it and the concentration.
- Draw each dose with a fresh sterile syringe/needle of the size specified by your prescriber or pharmacy; for many small subcutaneous dose volumes this may be a 0.5mL U-100 insulin syringe. Swab the stopper and let it dry each time, and dispose of every used needle in your sharps container straight away.
Storing it after mixing
Keep the reconstituted vial exactly as the written product instructions state, commonly in the fridge; do not freeze unless those written instructions specifically state that freezing has been validated for that product. The product has its own beyond-use date - follow that date rather than assuming the full preservative window. Do not use a vial whose appearance does not match the written instructions. For products expected to be clear, do not use if cloudy, discoloured, particulate, or not fully dissolved. Also do not use it if it is past its beyond-use date, has been stored outside instructions, may have been contaminated, or was mixed with the wrong diluent or volume.
Supplies for reconstituting GLP-1 powder
- 10mL bacteriostatic water vial - use only if your written product or pharmacy instructions specify bacteriostatic water. After first puncture, label the bacteriostatic water vial with the opening date and follow the vial label or pharmacy instructions for discard timing. Only preservative-containing multi-dose bacteriostatic water may be reused within its labelled or pharmacy discard window; preservative-free sterile water or saline ampoules or vials should be treated as single-use unless the supplied instructions explicitly state otherwise. Do not reuse leftover diluent if it is past its opened-vial limit, has been stored incorrectly, or may be contaminated.
- Sterile transfer syringe and drawing-up needle sized to the instructed diluent volume; use the gauge specified by your pharmacy and avoid unnecessarily large-bore needles for small vials.
- 0.5mL insulin syringes (31G, 6mm) - often easier for small GLP-1 dose volumes; use 1mL only if the instructed dose volume is more than 0.5mL and no more than 1mL, or if your prescriber or pharmacy specifies it. If the instructed volume is over 1mL, ask them what device and technique to use.
- Alcohol wipes (200-pack) - swab each stopper and let it dry before puncturing.
- 0.6L Sharpsafe container - a small locking sharps bin for used syringes and needles; choose a size and disposal pathway that matches your use and local requirements.
We supply the kit, not the medication - browse the full reconstitution supplies range.
When to call your prescriber or seek urgent care
Stop and contact your prescriber or supplying pharmacy before using the vial if:
- The powder will not fully dissolve, or the mixed solution's appearance does not match the written instructions.
- You are unsure of your concentration, your dose volume, or how many units to draw.
- You think you may have drawn the wrong dose - do not re-dose to "correct" it; call for guidance first.
If you feel unwell after using a prescribed medicine, follow your prescriber or pharmacy instructions or contact a registered health professional. For severe or life-threatening symptoms, call 000.
Frequently asked questions
What do I mix a GLP-1 powder product with?
Use only the diluent supplied or specified in your written product or pharmacy instructions. If they specify bacteriostatic water, use the exact volume specified in writing; do not add the whole vial unless the instructions explicitly say to. Only preservative-containing multi-dose bacteriostatic water may be reused within its labelled or pharmacy discard window; preservative-free sterile water or saline ampoules or vials should be treated as single-use unless the supplied instructions explicitly state otherwise. Some formulations or patients may require a different diluent.
How many units do I draw?
It depends entirely on your vial's concentration. On a U-100 insulin syringe, units = dose volume in mL times 100. Get your dose in mL or units from your prescriber or supplying pharmacy for your specific vial - do not reuse a number from a pen or another product.
Should I shake the vial to dissolve it faster?
No, unless your pharmacy instructions say to. Swirl gently or let it sit; shaking can cause foaming and unnecessary agitation. If it is slow to dissolve, follow the expected dissolution time in your written instructions.
What size syringe is best?
For many small subcutaneous dose volumes, a 0.5mL U-100 insulin syringe may be suitable if your prescriber or pharmacy has instructed syringe dosing; use the device and needle size they specify. A 0.5mL syringe is often easier for volumes up to 0.5mL; use a 1mL syringe only if the instructed dose volume is more than 0.5mL and no more than 1mL, or if your prescriber or pharmacy specifies it. If the instructed volume is over 1mL, ask them what device and technique to use.
