GLP-1 anti-drug antibodies: what the labels say

Short answer: every US label for Ozempic, Wegovy, Rybelsus, Mounjaro, Zepbound, Saxenda, Victoza and Trulicity reports that some patients develop anti-drug antibodies, from about 0.5% (Rybelsus) to 64.5% (Zepbound, weight reduction studies). The Mounjaro, Zepbound, Trulicity and Victoza labels state that no clinically significant effect on effectiveness was identified (Rybelsus and Wegovy say none on pharmacokinetics), and all warn that rates cannot be compared between products because the assays differ.

On this page: Rates by drug · How to read the numbers · Reactions · Canada · Tracking · Sources

Figures below are from DailyMed label text checked November 9, 2026.

Antibody rates in the US labels (section 6.2)

Product and population	Study group	Developed ADA	Cross-reactivity / neutralizing	Label statement on effect
Ozempic (semaglutide)	Adults with type 2 diabetes, glycemic control trials	32/3,150 (1%)	19 patients (0.6% of all) cross-reacted with native GLP-1	Neutralizing activity uncertain
Rybelsus (semaglutide tablets)	Adults with type 2 diabetes, 6 trials, 26 to 78 weeks	14/2,924 (0.5%)	7 patients (0.2% of all)	No clinically significant effect on PK identified
Wegovy (semaglutide)	Adults, Studies 2 and 3 (68 weeks), 2.4 mg arm	50/1,709 (3%)	28 of the 50 ADA-positive (56%)	No clinically significant effect on PK; insufficient evidence on PD, safety, effectiveness
Wegovy, higher-strength injection studies	Adults, Studies 8 and 9 (72 weeks), new assay	202/1,311 (15.4%) higher-strength; 34/304 (11.2%) 2.4 mg arm	36 (17.8% of 202) and 3 (8.8% of 34)	Clinical consequences of cross-reacting antibodies unknown
Wegovy, MASH	Adults with MASH, Study 11 (72 weeks)	3/763 (0.4%) with cross-reactive ADA	Reported as cross-reactive to native GLP-1	No clinically significant effect on PK
Mounjaro (tirzepatide)	Adults with type 2 diabetes, 7 trials, 40 to 104 weeks	2,570/5,025 (51%)	34% cross-reactive to native GIP, 14% to native GLP-1	Neutralizing vs drug activity ~2% (GIP, GLP-1 receptor); no clinically significant effect on PK or effectiveness
Mounjaro, pediatric	Ages 10+ with type 2 diabetes, 30-week placebo-controlled period	30/61 (49%)	26% GIP, 8% GLP-1	No neutralizing antibodies against receptor activity
Zepbound (tirzepatide)	Adults with obesity or overweight, weight reduction studies 1 and 2 (52+ weeks)	1,591/2,467 (64.5%)	40% GIP, 16.5% GLP-1	Neutralizing: 2.8% (GIP receptor), 2.7% (GLP-1 receptor); no clinically significant effect on PK or effectiveness
Zepbound, OSA	Adults with OSA and obesity	137/226 (60.6%)	37.2% GIP, 19.5% GLP-1	No neutralizing antibodies against tirzepatide activity
Saxenda (liraglutide)	Adults, with post-baseline assessment	42/1,505 (2.8%)	Neutralizing: 18 (1.2%)	Antibodies may be associated with more injection site reactions and low blood glucose reports, usually mild
Saxenda, pediatric	Pediatric trial, with post-baseline assessment	14/117 (12%)	1 (0.9%) cross-reactive to native GLP-1; no neutralizing antibodies	5 (4.3%) persistent; 2 (1.7%) positive through follow-up
Victoza (liraglutide)	Adults, five trials of 26+ weeks	102/1,104 tested (9%)	56 (5%) cross-reacted with native GLP-1; neutralizing 12 (1%)	No identified clinically significant effect on effectiveness; immunogenicity-related events 0.8% vs 0.4% comparator
Trulicity (dulaglutide)	Adults with type 2 diabetes, 24 to 104 weeks	64/3,907 (1.6%)	34 (0.9% of all) neutralizing; 36 (0.9%) anti-native GLP-1	No identified clinically significant effect on PK, PD, safety or effectiveness
Trulicity, pediatric	Ages 10+, 26-week controlled period (52-week follow-up)	4/101 (4%) at 26 wk; 6/103 (6%) at 52 wk	1 neutralizing; 3 (26 wk) or 4 (52 wk) anti-native GLP-1	Effect unknown in pediatric patients

Label effective dates on DailyMed: Ozempic June 1, 2026; Rybelsus January 30, 2026; Wegovy June 18, 2026; Mounjaro August 27, 2026; Zepbound August 28, 2026; Saxenda February 25, 2026; Victoza October 14, 2025; Trulicity June 16, 2026.

How to read these numbers

Different assays, different results. Each label states the incidence depends on assay sensitivity and specificity and that the percentages cannot be compared with other studies or products. The tirzepatide labels (51% and 64.5%) and the semaglutide labels (0.5% to 3%) measured antibodies with different methods, so the gap is not a ranking.
ADA is not the same as neutralizing. Most antibody-positive patients have antibodies that merely bind. The labels list neutralizing antibodies separately and they are rare: 0.9% (Trulicity), 1% (Victoza), 1.2% (Saxenda), 2.7% to 2.8% (Zepbound, weight reduction studies).
Cross-reactivity. Some antibodies also bind native GLP-1 or, for tirzepatide, native GIP. Wegovy's label says the clinical consequences of cross-reacting antibodies are unknown.
Newer Wegovy data. With a new assay the label reports 15.4% in the higher-strength studies and 11.2% in the 2.4 mg comparison arm over 72 weeks, versus 3% in the earlier 68-week studies, which is a reminder that the assay changes the number.

Antibodies, allergic reactions and injection-site reactions

Product	What the label says
Mounjaro, Zepbound	More patients who developed anti-tirzepatide antibodies had hypersensitivity reactions or injection site reactions than those who did not.
Saxenda	Antibodies may be associated with a higher incidence of injection site reactions and reports of low blood glucose; in trials these were usually mild and resolved while treatment continued.
Victoza	Immunogenicity-related events (for example urticaria, angioedema) occurred in 0.8% of Victoza-treated patients and 0.4% of comparator-treated patients; antibody-positive patients were not more likely to have them than antibody-negative patients.
Ozempic, Rybelsus, Trulicity, Wegovy	No association with reactions is stated in the immunogenicity subsection. See the hypersensitivity warning guide for the separate allergic reaction sections.

Canada

Health Canada authorizes each product with its own product monograph, and its adverse reaction and immunogenicity wording is written from the sponsor's Canadian filings, so numbers and phrasing can differ from the US labels above. This page does not quote Canadian antibody percentages; use the monograph PDFs linked under Sources for your product. The same general caution applies: antibody rates depend on the assay and are not comparable across products.

Using a GLP-1 tracker for this

Antibody results are not something patients routinely see. What you can record is what you notice: a rash, hives or swelling, injection-site redness or lumps, and the date you noticed them. Dated notes make it easier to describe a pattern to a prescriber or pharmacist.

Sources

This page summarizes official product labels as general information. It is not medical advice. Do not start, stop or change any medication based on this page. Labels are updated; check the current version for your product.

Frequently asked questions

Do GLP-1 medications cause antibodies?

Some patients develop anti-drug antibodies (ADA) to the medicine. The US labels report this in section 6.2 (Immunogenicity). Rates range from about 0.5% of Rybelsus-treated patients to about 64.5% of Zepbound-treated patients in weight reduction studies, depending on the drug and the assay. Every label says the observed incidence depends heavily on the assay, so rates should not be compared between products.

Why are tirzepatide antibody rates so much higher than semaglutide rates?

The labels report 51% of Mounjaro-treated adults (2,570 of 5,025) and 64.5% of Zepbound-treated patients (1,591 of 2,467) with anti-tirzepatide antibodies, against 1% for Ozempic, 3% for Wegovy 2.4 mg in Studies 2 and 3, and 0.5% for Rybelsus. The labels attribute no clinically significant effect on effectiveness to these antibodies, and they also warn that assay differences preclude meaningful comparisons, so a higher percentage does not mean a less effective or less safe product.

Do antibodies make a GLP-1 medicine stop working?

The US labels for Mounjaro, Zepbound, Trulicity and Victoza state that no clinically significant effect of the antibodies on effectiveness was identified (the Trulicity label also says none on pharmacokinetics, pharmacodynamics or safety). Rybelsus and Wegovy report no clinically significant effect on pharmacokinetics, with insufficient information on effectiveness. Ozempic says the neutralizing activity of its antibodies is uncertain. Talk to your prescriber if you think a medicine has stopped working; Glidedose, a GLP-1 tracker, can only show you the dates and notes you logged.

Are antibodies linked to allergic or injection-site reactions?

For Mounjaro and Zepbound, the labels say more patients who developed anti-tirzepatide antibodies had hypersensitivity or injection-site reactions than those who did not. The Saxenda label says antibody presence may be associated with more injection site reactions and reports of low blood glucose, usually mild. The Victoza label says patients with anti-liraglutide antibodies were not more likely to have immunogenicity-related events (such as urticaria or angioedema) than those without.

What are neutralizing antibodies?

Neutralizing antibodies are antibodies shown in a laboratory test to block the drug's activity. The labels report them as a small share: for example 1.2% of Saxenda-treated adults, 1% of Victoza-treated patients, 0.9% of Trulicity-treated patients, and 2.8% (GIP receptor) and 2.7% (GLP-1 receptor) of Zepbound-treated patients in weight reduction studies. The Ozempic label says neutralizing activity is uncertain.

Do the Canadian monographs report the same?

Health Canada-authorized product monographs carry their own adverse reaction and immunogenicity sections, written from the sponsor's Canadian filings, so counts and wording can differ from the US labels. Check the current monograph PDF for your product (links below); this page does not quote Canadian antibody percentages.

Does this page tell me what to do about antibodies?

No. It summarizes official labels. Do not start, stop or change a medication because of this page; speak to a prescriber or pharmacist.

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