Side effects

Injection-site reactions

Pending medical review

By Joshua Nichvolodoff · Fact-checked against sources November 2, 2026 · Next review due May 1, 2027

Clinical review: not yet reviewed by a clinician. How review works · Editorial policy

Redness, itching or bruising where you inject is reported with GLP-1 medicines, more with some than others. Here is what the labels and a 2026 meta-analysis say — and the rare signs that need urgent help.

How often it was reported

Zepbound's label lists bruising, redness, itching, pain and rash at the injection site in 6–8% of people versus 2% on placebo, and more often in people who developed antibodies to tirzepatide[1]. Mounjaro's label reports 3.2% versus 0.4%[3]; Wegovy's reports 1.4% versus 1%[2]; and Ozempic's reports 0.2%[4].

What a meta-analysis found

A 2026 meta-analysis of 14 randomized trials found a higher risk of injection-site reactions with GLP-1 medicines than with comparators, and found generalized skin reactions infrequent[5].

Rotating sites

The Medication Guides say to change your injection site with each injection[2][4]. When you log an injection, the Light Years tracker suggests the next site in a simple rotation.

General information from product labels and published studies — not medical advice.

Sources

  1. ZEPBOUND (tirzepatide) injection — prescribing information and Medication Guide (revised 04/2026). U.S. Food and Drug Administration, April 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/217806Orig1s050lbl.pdf. Accessed November 2, 2026. Back to the text
  2. WEGOVY (semaglutide) injection and tablets — prescribing information and Medication Guide (revised 06/2026). U.S. Food and Drug Administration, June 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/218316s007lbl.pdf. Accessed November 2, 2026. Back to the text
  3. MOUNJARO (tirzepatide) injection — prescribing information (revised 08/2026). U.S. Food and Drug Administration, August 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/215866s044s045lbl.pdf. Accessed November 2, 2026. Back to the text
  4. OZEMPIC (semaglutide) injection — prescribing information (revised 05/2026). U.S. Food and Drug Administration, May 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/209637s038lbl.pdf. Accessed November 2, 2026. Back to the text
  5. Injection-site and dermatologic reactions associated with GLP-1 receptor agonists: meta-analysis of randomized trials and real-world evidence. Diabetes, Obesity and Metabolism, March 2026. https://pubmed.ncbi.nlm.nih.gov/41395692/ · DOI 10.1111/dom.70382 · PMID 41395692. Accessed November 2, 2026. Back to the text

Figures marked “as reported” are historical: they show what the source said on that date, not today's price or rule.

Changes to this page

  • — First published.

Substantive corrections are also logged at corrections.

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