Fatigue on GLP-1 medicines: what the labels report

Fatigue is listed as an adverse reaction in the FDA labels for semaglutide and tirzepatide, but in the pivotal weight-management trials it affected a minority of patients, and it was also reported on placebo.[1][2]

How often it was reported

Wegovy 2.4 mg: fatigue (including asthenia) in 11% of patients versus 5% on placebo across three placebo-controlled trials.[1]
Zepbound: fatigue (including asthenia, lethargy, and malaise) in 5%, 6%, and 7% at 5, 10, and 15 mg versus 3% on placebo.[2]
Ozempic: the label lists fatigue among other adverse reactions seen at a frequency above 0.4%.[3]

Related warnings in the label

Both the Wegovy and Zepbound labels warn about acute kidney injury. Wegovy’s label describes postmarketing reports, in some cases requiring hemodialysis, in patients with volume depletion; nausea, vomiting, and diarrhea can lead to dehydration.[1][2]

What the labels do not say

The labels report how often fatigue occurred, not how long it lasted for a typical patient, and they do not establish that any supplement prevents it. Persistent or severe tiredness, dizziness, or signs of dehydration are reasons to contact a clinician.

References

U.S. Food and Drug Administration. WEGOVY (semaglutide) injection prescribing information, revised 2025 (Table 2 and section 5.5). https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/215256s024lbl.pdf. Checked October 15, 2026.
U.S. Food and Drug Administration. ZEPBOUND (tirzepatide) injection prescribing information, revised 2025 (Table 1 and section 5.3). https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/217806Orig1s020lbl.pdf. Checked October 15, 2026.
U.S. Food and Drug Administration. OZEMPIC (semaglutide) injection prescribing information, revised 2025 (section 6.1). https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/209637s025lbl.pdf. Checked October 15, 2026.

This page summarizes published research and regulatory documents. It is not medical advice and does not recommend starting, stopping, or changing any medication.