“Commercial IgG food panels reliably diagnose food intolerances.”
Commercial IgG food panels do not reliably diagnose food intolerances.
A list of "positive" foods from an IgG panel is not a list of foods you need to avoid. If certain foods seem to cause symptoms, a clinician can help you find the cause with tests that are proven to work.
Before buying an IgG panel or cutting out foods, talk with a clinician about your symptoms.
Talk to a healthcare professional if: you get hives, swelling of the lips, tongue or throat, wheezing or trouble breathing after eating a food, or you are thinking about cutting out several foods because of a test result.
Allergy experts find no proof that food IgG tests identify the foods that cause intolerance, and IgG mostly reflects foods a person has been eating. Two sham-controlled trials in people who already had IBS found that cutting the flagged foods eased symptoms somewhat, but that is a treatment result, not a diagnosis, and in the 2004 trial the flagged foods were most often milk and wheat, so the trials do not show the test can pinpoint a person's problem foods.
Commercial IgG food panels do not reliably diagnose food intolerances. A positive IgG result is likely a normal sign that you have eaten that food, not proof that it makes you sick.
The American Academy of Allergy, Asthma & Immunology says IgG to foods is likely a normal immune response to eating them, that the test has never been proven to do what it reports, and it recommends against using IgG tests to diagnose food allergies or intolerances. Two sham-controlled trials in people with IBS, from 2004 and 2025, found that diets removing IgG-positive foods eased symptoms somewhat more than a fake diet. Both studied people who already had IBS, and that is different from showing a panel can tell which foods cause a problem for anyone who takes the test. In the 2004 trial, the IgG diet cut milk for 84% of people and wheat for 49%, while the fake diet cut milk for only 1% and wheat for 8% and more often cut potato and rice, so that trial cannot tell whether the test found each person's problem foods or simply steered people away from milk and wheat. Both trials also had ties to test makers: the 2025 trial was funded by the company that makes its test, and in the 2004 trial the testing company ran the tests and wrote the diet sheets. Our card "An IgG-guided elimination diet improves IBS symptoms." covers those trials in detail.
- American Academy of Allergy, Asthma & Immunology. The Myth of IgG Food Panel Testing. AAAAI Conditions Library. Dated May 12, 2026
- Atkinson W, Sheldon TA, Shaath N, Whorwell PJ. Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial. Gut. 2004;53(10):1459-1464. DOI: 10.1136/gut.2003.037697. PMID: 15361495. PMCID: PMC1774223
- Singh P, Chey WD, Takakura W, Cash BD, Lacy BE, Quigley EMM, Randall CW, Lembo A. A Novel, IBS-Specific IgG ELISA-Based Elimination Diet in Irritable Bowel Syndrome: A Randomized, Sham-Controlled Trial. Gastroenterology. 2025;168(6):1128-1136.e4. DOI: 10.1053/j.gastro.2025.01.223. PMID: 39894284
- Graham L. NIAID releases guidelines on diagnosis and management of food allergy. American Family Physician. 2011;83(12):1492-1496