The quick answer

Step What you use
Add the liquid to the powder The diluent your prescriber or pharmacy supplied or specified, drawn with a sterile syringe and drawing-up needle sized to the volume
Draw and inject each dose For many small doses, a 0.5mL U-100 insulin syringe (31G, 6mm), if your prescriber or pharmacy has specified syringe dosing
Keep it clean An alcohol wipe on every stopper, every time
Finish safely A 0.6L Sharpsafe container

Does yours even need reconstituting?

Only if it arrives as a dry powder or cake with written reconstitution instructions. If your instructions say it's already liquid, don't add anything. See our GLP-1 needle and syringe size guide for supplies.

Reconstitution supplies arranged on a clean bench: bacteriostatic water vial, transfer syringe, insulin syringe, and alcohol wipe
Reconstitution supplies should match the written product or pharmacy instructions, including the specified diluent, transfer syringe, dose syringe, and hygiene supplies.

How much water to add

Add only the diluent and volume your pharmacy specifies. Choosing your own volume changes every dose you draw afterwards.

Your dose volume comes from the stated final concentration, or the total drug in the vial and the labelled final volume. Don't calculate from the diluent you added unless your instructions say the two volumes are the same.

Get your dose volume or syringe units for your vial in writing from your pharmacy label or prescriber, and don't work it out from online examples. Our guide to reading an insulin syringe has the full mL-to-units table.

Step by step

Clean vial and alcohol wipe arranged before stopper disinfection
Use a fresh alcohol wipe for each vial stopper and let the stopper dry before puncturing.
  1. Wash your hands. Set out the powder vial, diluent, sterile transfer syringe and needle, fresh alcohol wipes and your sharps container.
  2. Scrub each vial stopper with its own fresh wipe and let it air-dry.
  3. Draw the prescribed volume of diluent. Push in an equal volume of air first only if your pharmacy instructions say to.
  4. Insert the needle into the powder vial and run the diluent down the inside of the glass, not onto the powder, to limit foaming.
  5. Withdraw the needle. Swirl gently, or let it sit, until it fully dissolves and looks as your instructions describe. Don't shake unless told to.
  6. Label the vial with the mixing date and concentration. A clear solution doesn't confirm sterility or the right concentration, so follow the written directions from here.
  7. Draw more than one dose only if your instructions say it's a multi-dose vial and give a beyond-use date. Otherwise don't keep or reuse leftovers; contact the pharmacy.
  8. Where repeat withdrawals are allowed, use a fresh sterile syringe of the specified size for each dose, often a 0.5mL U-100 insulin syringe. Swab the stopper and let it dry each time, and put every used needle straight into your sharps container.

Storing it after mixing

Store the mixed vial exactly as instructed, usually in the fridge. Don't freeze it unless your instructions say freezing has been validated. Follow the product's beyond-use date rather than the diluent's. Bacteriostatic water alone doesn't make a mixed vial safe for multi-dose use.

Don't use the vial if it:

  • looks different from the instructions, or is cloudy, discoloured, has particles or hasn't fully dissolved when it should be clear
  • is past its beyond-use date or was stored outside its instructions
  • may be contaminated, or was mixed with the wrong diluent or volume

Supplies for reconstituting GLP-1 powder

We supply the kit, not the medicine. Browse the full reconstitution supplies range.

When to call your prescriber or seek urgent care

Stop and contact your prescriber or pharmacy before using the vial if:

  • The powder won't fully dissolve, or the solution doesn't look as described.
  • You're unsure of your concentration, dose volume or units.
  • You think you drew the wrong dose. Don't re-dose to correct it.

If you feel unwell after a dose, follow your prescriber's 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?

Only the diluent your instructions supply or specify, in the exact volume written. Don't add a whole vial of bacteriostatic water unless told to. Some formulations or patients need a different diluent.

  • Preservative-containing bacteriostatic water can be reused within its labelled or pharmacy discard window, for one person only, with a new sterile syringe and needle each time. Write the opening date on it, never share it, and discard it if sterility may be compromised.
  • Treat preservative-free sterile water or saline as single use unless your instructions say otherwise.
  • For a glass ampoule, withdraw with the filter needle or filter straw your pharmacy specifies, then swap to a new sterile non-filter needle before adding it to the powder. Never inject with a filter needle.
  • Don't reuse leftover diluent that is past its opened limit, stored wrongly or possibly contaminated.

A vial storage case keeps vials upright, cushioned and organised, but doesn't control temperature. When travelling, keep to the product's temperature instructions and use cooled transport if it needs refrigeration.

How many units do I draw?

It depends on your vial's concentration. On a U-100 syringe, units = dose volume in mL x 100. Get your dose in mL or units for your vial from your prescriber or pharmacy, never from a pen or another product.

Should I shake the vial to dissolve it faster?

No, unless your pharmacy says to. Swirl gently or let it sit, and allow the dissolving time in your instructions.

What size syringe is best?

For volumes up to 0.5mL, a 0.5mL U-100 insulin syringe is usually easiest to read. A 1mL syringe suits volumes up to 1mL. Use the device and needle your prescriber or pharmacy specifies, and ask them about anything over 1mL.