Side effects

Fatigue on GLP-1 medications

Some people feel more tired on GLP-1 medications. Here is what the product labels report — the main source we could find — and the symptoms the labels say can point to something else.

What the labels report

Fatigue (including weakness) was reported by 11% on Wegovy 2.4 mg versus 5% on placebo^[1]; Canada's Wegovy monograph gives 11% versus 5.1%^[3]. On Zepbound it was 5%, 6% and 7% at 5, 10 and 15 mg, versus 3% on placebo^[2]. In Mounjaro's cardiovascular trial in type 2 diabetes, 10% reported fatigue^[4].

The limits of this evidence

We could not find independent studies of fatigue on these medicines beyond the trial data in the labels and monographs above^[1]. So this page can say how often it was reported, but not why, or how long it lasts.

When tiredness might be something else

The Medication Guides list dizziness, weakness, shakiness, sweating, confusion and a fast heartbeat as possible signs of low blood sugar, a risk that rises with insulin or a sulfonylurea^[1][2]. Feeling faint or dizzy can also come from low blood pressure or dehydration^[1].

General information from product labels — not medical advice.