Pen injector
Also called: autoinjector pen
Clinical reviewer: Jacob Moore, MD · Last checked September 16, 2026
What is a GLP-1 pen injector?
Pen injector is a prefilled device used to inject GLP-1 medications subcutaneously, either as a single-dose pen used once and discarded or a multi-dose pen reused for several doses. GLP-1 pens, such as those for Trulicity, Zepbound, Victoza, and Saxenda, are injected into the abdomen, thigh, or upper arm.
What's the difference between single-dose and multi-dose pens?
Single-dose pens, such as dulaglutide's Trulicity pen, are prefilled with one weekly dose — 0.75 mg, 1.5 mg, 3 mg, or 4.5 mg — and are discarded after each injection [1]. Zepbound is likewise supplied as a single-dose pen, alongside a single-dose vial and a KwikPen delivering four 0.6 mL doses, injected into the abdomen, thigh or upper arm [2]. Multi-dose pens work differently: a Victoza pen delivers a range of daily doses, from 0.6 mg to 1.8 mg, drawn from one 6 mg/mL prefilled pen, and a Saxenda pen is used daily through its titration and maintenance schedule before being replaced [3][4].
Are GLP-1 pens ever shared between patients?
No. Zepbound's FDA label warns that its KwikPen must never be shared between patients, even if the needle is changed, because of the risk of transmitting blood-borne pathogens [2]. The warning applies to the needle specifically, since changing it alone doesn't eliminate the contamination risk from a previously used pen [2].
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This entry is for education and is not medical advice. Talk with a licensed clinician about your own situation before starting, stopping, or changing any treatment.
