Vial and syringe

What it means

Zepbound is sold in single-dose vials as well as pens, mainly through the maker's self-pay pharmacy. A single-dose vial holds one dose. You draw it into a syringe and inject it under the skin, then throw the vial away even if a little liquid is left.

Many compounded GLP-1 products come in multi-dose vials, often with instructions in "units" on an insulin syringe rather than in milligrams. The FDA has received reports of overdoses, some needing hospital care, from people and clinicians confusing milligrams, milliliters and units.

If you use a vial, ask the pharmacist to show you how to draw up your exact dose and confirm it in milligrams. Use a new sterile syringe every time, and do not mix medicines in one syringe unless told to.

Dispose of syringes in a sharps container.

Why it matters

Most serious GLP-1 dosing errors reported to the FDA involved vials and syringes, not prefilled pens.