The quick answer

Step What you use
Add the liquid to the powder A sterile syringe sized for the volume, with a draw needle that suits the vial. Use 18G only when your instructions allow it.
Draw each dose For small subcutaneous (under the skin) doses, a fresh 0.5mL U-100 insulin syringe (31G, 6mm) when directed. Otherwise, the syringe and needle specified for your route and volume.
Keep it clean An alcohol wipe on every stopper
Finish safely A 0.6L Sharpsafe container

How much water to add

If bacteriostatic water is specified, the volume you add sets the concentration, and so how many units make your dose.

Concentration (mg/mL) = peptide amount (mg) divided by water added (mL). To draw X mg from a vial of Y mg/mL, the volume is X divided by Y. On a U-100 syringe, units = mL x 100. This is maths only, not a dose.

Add the volume specified for your vial rather than your own, because it changes every amount you draw afterwards. Our guide to reading an insulin syringe has the full mL-to-units table.

A 0.5mL and a 1mL insulin syringe shown for comparing barrel markings
A 0.5mL and a 1mL insulin syringe shown for comparing barrel markings. Use only the syringe type and size specified for the route and volume.

Step by step

  1. Wash your hands and set out the powder vial, bacteriostatic water, draw needle, an alcohol wipe and your sharps container.
  2. Swab both stoppers and let them air-dry.
  3. Push air equal to the volume into the water vial, to avoid a vacuum, then draw the specified volume.
  4. Run the water down the inside wall of the powder vial, not onto the powder.
  5. Swirl gently or let it sit until clear. Don't shake unless your instructions say to, as it foams the solution and may damage the product.
  6. Label the vial with the date and concentration, and refrigerate it.
  7. Draw each dose with a fresh sterile syringe of the specified type, swab the stopper each time and bin used needles straight away.

Storing it

Refrigerate at 2 to 8 C unless your instructions say otherwise. Bacteriostatic water's 28-day multi-dose window doesn't prove retatrutide stays stable. It applies to the water vial after first puncture, for one person, with clean technique, and never overrides product limits. Follow the shortest of the product's stability limit, its instructions and local multi-dose rules. Discard any solution that turns cloudy or develops particles. Our guide to how long reconstituted peptides last has the detail.

A vial storage case keeps vials upright, cushioned and organised, but doesn't control temperature. When travelling, use an insulated cold-pack system to stay within range.

Supplies for reconstituting retatrutide

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

When to stop and seek advice

  • The powder won't fully dissolve, or the solution is cloudy or has particles: don't inject it.
  • You're unsure of the concentration, dose volume or units.
  • You think you drew the wrong amount: don't re-dose to correct it; get advice first.
  • Pus, spreading redness, warmth, swelling, fever, severe pain, or symptoms that persist or worsen over 24 to 72 hours: seek medical advice promptly.
  • Persistent vomiting, severe stomach pain (especially radiating to the back), or signs of an allergic reaction - hives, facial or throat swelling, trouble breathing (call 000).

Frequently asked questions

Is retatrutide approved?

No. It's in clinical trials and not approved for general use in Australia. Use it only within an approved clinical trial, under the trial team's instructions.

What do I reconstitute retatrutide with?

Only the diluent your written instructions specify. If that's bacteriostatic water, add the stated volume.

How many units do I draw?

It depends on your vial's concentration. Units = dose volume in mL x 100. Get the figure for your vial, never from another product.

Should I shake the vial?

No, unless your instructions say to. Swirl gently or let it sit.