Key takeaways:
There are many at-home tests for both food allergies and sensitivities, but most don’t have enough evidence to support their use.
Tracking your symptoms and food intake can help you identify potential food allergies or sensitivities.
At home breath tests can be used to test for lactose intolerance. But you don’t need a test to make the diagnosis.
Have you ever wondered if something you ate gave you a rash or an upset stomach? Food allergies are common and affect about 10% of adults in the U.S. Food sensitivities are even more common.
Food allergies and food sensitivities are often grouped together, but they’re not the same. A food allergy happens when the immune system overreacts to a food. A food sensitivity is usually related to how your body digests food.
At-home food allergy testing kits promise quick answers. But many of these tests have important limitations and may even lead to confusing or misleading results. That’s why it’s important to understand what these tests can — and can’t — tell you before relying on them for answers.
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How to test for food allergies at home
The first step in allergy testing is to pay attention to which foods seem to trigger your symptoms. You need to have symptoms that suggest a food allergy before you test for one. Without symptoms, a positive or negative allergy test result won’t mean very much.
Food allergies happen when the immune system mistakenly treats a food as harmful. In response, the body makes antibodies called immunoglobulin E (IgE). These antibodies can trigger an allergic reaction each time you eat that food. IgE reactions happen quickly, usually within minutes to an hour after eating the trigger food.
Symptoms of a food allergy include:
Hives or itching
Swelling of the lips, tongue, or throat
Vomiting or stomach pain
Wheezing or trouble breathing
Dizziness or fainting
In severe cases, food allergies can cause anaphylaxis, a life-threatening allergic reaction.
There are two types of home allergy tests marketed to people who are worried about food allergies — but one should be interpreted with great caution, and the other shouldn’t be used at all.
IgE food allergy tests
Many at-home food allergy tests measure immunoglobulin E (IgE) antibodies to dozens of foods at once. These tests involve doing a finger-prick sample that you send to a lab. But food allergy testing works best when it’s targeted to specific foods linked to symptoms.
Testing many foods at once increases the chance of false-positive results. In other words, a test may suggest you’re allergic to a food even if you aren’t. This could lead you to eliminate foods that you don’t actually need to avoid.
Given that the American Academy of Allergy, Asthma & Immunology recommends IgE testing for a food only when symptoms suggest a possible food allergy, and at-home kits test IgE levels for many foods at once, this type of test isn't recommended.
IgG tests
Some at-home tests marketed for food allergies measure immunoglobulin G levels (IgG), instead of IgE.
But IgG antibodies aren’t involved in an allergic reaction. Experts don’t recommend using IgG testing to diagnose food allergies because there’s no evidence that these tests accurately identify food triggers. In fact, IgG antibodies may simply reflect the foods you eat regularly — not foods causing symptoms.
How to test for food sensitivities at home
Unlike food allergies, food sensitivities — also known as food intolerances — don’t involve IgE antibodies. They’re usually related to digestion or difficulty processing certain foods. So, you can’t test for them with allergy tests.
With food sensitivities, symptoms are often delayed. They may happen hours or even days after eating a trigger food. Common examples include lactose intolerance and non-celiac gluten sensitivity.
Symptoms may include:
Bloating or gas
Abdominal pain
Diarrhea
Fatigue
Headache or migraines
For many people, keeping a food and symptom journal may be more helpful than taking an at-home sensitivity test. Tracking what you eat and how you feel afterward can sometimes reveal patterns over time.
At-home tests for food intolerances usually aren’t needed. And, in most cases, they aren’t accurate — with one exception: breath testing for lactose intolerance.
At-home breath tests for lactose intolerance
Lactose intolerance can be diagnosed with a special breath test. This test measures hydrogen and methane levels in your breath after you drink something with lactose. Some companies offer versions of this test that can be done at home and then sent back to the lab.
Hydrogen breath testing is one of the few at-home food intolerance tests supported by evidence. But these tests can be expensive. And you don’t necessarily need a test to know if you have a lactose intolerance. Many people can identify lactose intolerance based on symptoms alone.
If milk or dairy products consistently cause bloating, gas, or diarrhea, try avoiding dairy for a period of time. If symptoms improve, try reintroducing it later. If your symptoms come back, that often means that lactose is the trigger.
Other at-home tests for food sensitivities
There are several other types of testing for food sensitivities that are marketed for home use. But most haven’t been proven to be accurate in diagnosing food sensitivities:
Genetic tests: These tests use saliva or cheek swabs to look for genes related to food intolerances. But having these genes doesn’t mean you’ll actually have symptoms.
Hair tests: These tests claim to measure mineral content or “bioresonance” patterns in hair samples. There’s no good evidence that hair testing can accurately diagnose food sensitivities.
IgG tests: Experts don’t recommend IgG testing for food sensitivities. As with food allergies, IgG results can be misleading because they often reflect foods that you tolerate and eat regularly.
Are food allergy and sensitivity tests accurate?
At-home allergy tests are more convenient than a visit to your provider. But most of these tests won’t provide valid or helpful results. At-home allergy tests are considered direct-to-consumer tests. The FDA doesn’t always review these tests to make sure that they’re accurate. This makes them harder to trust.
Most at-home food sensitivity tests aren’t accurate or well supported by evidence. One possible exception is hydrogen breath testing for lactose intolerance, which can help diagnose trouble digesting lactose.
Should I see an allergist?
If you suspect a food allergy, you may want to see an allergist. Although it may feel less convenient, there are several benefits to consulting with an allergist. And it may save you time and money in the long run.
To start, an allergist can help determine whether testing is actually needed and which foods should be tested. They can also offer an allergy skin test, which may be more accurate than blood tests. And the allergist can help you understand your results. If an IgE test is positive but your symptoms aren’t clear, an oral food challenge may be recommended. This can help you avoid eliminating foods unnecessarily.
If you’re diagnosed with a true food allergy, an allergist can also help guide you on how to best avoid that food in the future and provide a treatment plan in case of a severe allergic reaction.
But, if you suspect a food sensitivity, seeing your regular healthcare provider or a gastroenterologist would be more helpful.
Frequently asked questions
The cost of at-home food allergy tests varies depending on the type of test and the number of foods it covers. Many kits cost between $100 and almost $400. And they’re usually not covered by insurance.
Allergy testing kits will usually test for the foods that are most likely to cause allergies. The most common foods include peanuts, tree nuts, milk, eggs, soy, wheat, shellfish, and fish. Some at-home kits test dozens or even hundreds of foods at once.
The cost of at-home food allergy tests varies depending on the type of test and the number of foods it covers. Many kits cost between $100 and almost $400. And they’re usually not covered by insurance.
Allergy testing kits will usually test for the foods that are most likely to cause allergies. The most common foods include peanuts, tree nuts, milk, eggs, soy, wheat, shellfish, and fish. Some at-home kits test dozens or even hundreds of foods at once.
The bottom line
At-home food allergy and food sensitivity tests may sound like an easy way to get answers. But in most cases, they’ll create more confusion than clarity. Many tests aren’t well supported by evidence, and broad food panels are more likely to lead to false positives. When it comes to food reactions, symptoms matter more than long lists of test results. True food allergies usually cause symptoms quickly after eating a trigger food, whereas food intolerances tend to cause delayed digestive symptoms.
If you think a food is causing problems, the best place to start is to pay attention to patterns in your symptoms. Talk with a healthcare professional before cutting multiple foods out of your diet.
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References
American Academy of Allergy, Asthma & Immunology. (2020). The myth of IgG food panel testing.
American Academy of Allergy, Asthma & Immunology. (2023). Testing and diagnosis.
Barrett, S. (2020). Why bioresonance hair testing is preposterous. Quackwatch.
Food Allergy Research & Education. (n.d.). Oral food challenge.
Gupta, R. S., et al. (2019). Prevalence and severity of food allergies among U.S. adults. JAMA.
Kelso, J. M. (2018). Unproven diagnostic tests for adverse reactions to foods. The Journal of Allergy and Clinical Immunology.
Parrish, C. P. (2023). A review of food allergy panels and their consequences. Annals of Allergy, Asthma & Immunology.
Shrestha, A., et al. (2019). Validity of a portable breath analyser (AIRE) for the assessment of lactose malabsorption. Nutrients.
U.S. Food and Drug Administration. (2019). Direct-to-consumer tests.
Warren, C. M., et al. (2020). Epidemiology and burden of food allergy. Current Allergy and Asthma Reports.
