Which needle and syringe are used for compounded GLP-1 injections?

Which syringe is used for compounded semaglutide or tirzepatide?

Quick answer: A U-100 insulin-type syringe, marked in units: 100 units equal 1 mL. Use the one your pharmacy or REMEVi provider sends with your vial.

Use the dose on your label from your REMEVi provider; this page explains the units, it does not set your dose.

REMEVi ships compounded semaglutide and tirzepatide in multiple-dose vials, and you draw each dose with an insulin-type syringe marked U-100. “U-100” is insulin’s strength label: Lilly’s Humulin® R label reads “100 units/mL (U-100)” (revised 06/2023). On these syringes, the numbers on the barrel count units of liquid, not milligrams of medicine — here is how units turn into mg.

The FDA asks prescribers and compounders to “provide patients with the appropriate syringe size for the intended dose and counsel patients on how to measure the intended dose using the syringe” (FDA alert, July 26, 2024). The syringe that comes with your vial was chosen for that reason. If you need more, or yours look different from before, ask before switching.

What syringe sizes are there?

Quick answer: U-100 insulin syringes come in 0.3 mL (30 units), 0.5 mL (50 units) and 1 mL (100 units). The 0.3 mL size can come with half-unit marks.

embecta (formerly BD Diabetes Care) says its Ultra-Fine™ insulin syringes come “in 1 mL, 0.5 mL, and 0.3 mL capacities,” designed “with large dose unit markings, with ½ unit scale marking available on the 0.3mL barrel” (product page, © 2026). Its BD Veo™ card lists the same three sizes, including a half-unit 3/10 mL version (© 2022).

Because every size is U-100, one unit is the same volume on all of them. What changes is how many units fit and how far apart the marks are. Read the scale printed on your own barrel to see what each line is worth before you draw.

What needle length is used?

Quick answer: embecta lists 6, 8 and 12.7 mm needles. Its 6 mm × 31G is the shortest, and shorter needles may lower the risk of an accidental injection into muscle.

embecta’s page says “the Ultra-Fine™ 6mm x 31G needle is the shortest insulin syringe needle length offered by embecta,” and that shorter needles “are effective, well tolerated, less painful and may lower the risk of an accidental intramuscular injection, when compared to longer needles” (embecta). The BD Veo™ card lists the 6 mm needle as 15/64 inch × 31G (embecta card, © 2022).

We could confirm only the 31G gauge from a live maker page, so the table leaves the other gauges blank rather than guessing.

The needle comes attached to the syringe your pharmacy or provider sends. Don’t switch lengths on your own.

Why does the syringe size matter?

Quick answer: A syringe much larger than your dose makes small amounts easy to misread. The FDA linked this to overdoses with compounded semaglutide.

The FDA said it was “aware of some instances in which patients have been given syringes that are significantly larger than the prescribed volume.” In several reports, patients told to draw 5 units (0.05 mL) on a 1 mL U-100 syringe drew 50 units instead. Most reports described patients taking five to 20 times the intended dose (FDA, July 26, 2024).

For its own brand vials, Lilly’s Zepbound® label (revised 08/2026) tells prescribers to have patients use “a syringe appropriate for dose administration (e.g., a 1 mL syringe capable of measuring a 0.5 mL or 0.6 mL dose).” That is a brand fact about Zepbound® vials. Wegovy®, Ozempic®, Zepbound® and Mounjaro® are FDA-approved brand-name products that REMEVi does not sell. Facts quoted from their labels describe those products only. We name them to orient you, not to suggest a compounded medication is equivalent to them.

Can I reuse a syringe or needle?

Quick answer: No. The FDA says to use a new, sterile needle and syringe for every dose; reusing them can contaminate the medicine in the vial.

The FDA (October 1, 2026): “Always use a new, sterile needle and syringe for each dose. Reusing needles or syringes can result in contamination of the medication.” With a multiple-dose vial that matters twice: a used needle goes back into the medicine you will draw from for the next few weeks.

The maker agrees: embecta says insulin syringe needles “are recommended to be used only once and are no longer sterile after that.” And Lilly’s brand label tells vial users to “always use a new syringe and needle for each injection.”

How do I throw away used syringes?

Quick answer: Put each one in a sharps container right after use, then follow your community’s rules when the container is about three-quarters full (FDA).

The FDA (content current as of August 10, 2023) recommends two steps. Step 1: place all needles and other sharps in a sharps disposal container immediately after use. Step 2: when the container is about three-quarters full, follow your community guidelines for getting rid of it. Don’t put loose needles in household trash, and don’t recycle sharps containers.

If you don’t have an FDA-cleared sharps container, Lilly’s FDA-approved vial instructions (revised April 2026) say a household container can work if it is:

• made of heavy-duty plastic
• closed with a tight-fitting, puncture-resistant lid that sharps can’t come out of
• upright and stable during use
• leak-resistant
• labeled to warn of hazardous waste inside

Questions about your vial, syringe or label? Message your REMEVi care team or call (702) 352-4746 before you inject.

Compounded semaglutide and tirzepatide are prepared by licensed pharmacies for an individual prescription. They are not FDA-approved, and the FDA has not reviewed them for safety, effectiveness or quality.