My kitchen table is currently cluttered with small test tubes, envelopes, and plastic lancets. On one side, I have a package containing all the necessary components to perform a food intolerance blood test from a well-known company in this industry, along with a food and environmental allergy test bundle that set me back just over £200.
On the opposite side of the table, I have everything required to conduct an advanced ALEX2 allergy blood test, which I obtained from the allergy clinic led by Dr. Helen Evans-Howells, a general practitioner and allergy expert with clinics in Hampshire, Belfast, and online. This test costs £295 and includes two lancets for pricking my fingertips, a blood collection tube, disinfecting wipes, and a return envelope. In the center of the table rests a bowl of hot water where my left hand is soaking. Additionally, I’ve cut a lock of hair, which is now stored in a sandwich bag, ready to be shipped to a lab tomorrow for bioresonance testing. My objective is to compare the results from all three tests, which will be conducted on the same day. Since I do not have any food or environmental allergies or intolerances, I expect that all three tests will yield identical results: negative.
My daughters are eager to observe me as I draw my own blood, but I send them out of the room. The last time I attempted a home blood test for hormonal levels, I began to feel lightheaded and, with everyone else in bed, had to lie down on the kitchen floor while still trying to collect the required 30ml of blood. I am not looking forward to this procedure, and I prefer to avoid an audience.
It is challenging to ascertain the total expenditure on home allergy or intolerance tests, as well as the number of individuals utilizing them. However, globally, allergy diagnostics, including those conducted in hospitals, generate approximately $5.3 billion annually, while the market for at-home food sensitivity tests was estimated at $2.6 million in 2025.
If these figures are accurate, they are astonishing for two reasons. First, without a healthcare professional familiar with your medical history, even the most reliable allergy test results can be difficult to interpret, and not all tests available on the market meet high standards.
Second, aside from the hydrogen breath test for lactose intolerance and blood tests for celiac disease—which are medically validated alongside biopsies—there is no scientific evidence supporting the efficacy of the various intolerance tests available for purchase online or through alternative healthcare practitioners.
While living with allergies and food intolerances can be quite challenging, it is important to note that they are distinct conditions. Approximately 6% of adults have a clinically confirmed food allergy, whereas about 24% report experiencing at least one intolerance.
There are two primary types of allergies: immediate IgE-mediated and delayed non-IgE allergies. The latter typically leads to gastrointestinal symptoms that may manifest hours or days after exposure and are often challenging to diagnose since they do not show up in blood tests. IgE allergies occur when our immune system mistakenly identifies a harmless substance, such as dairy, as a threat. Once this error occurs, the blood will contain immunoglobulin E (IgE) antibodies specific to dairy.
IgE allergies can manifest in various forms, including hay fever, dust mite allergies, and food allergies, leading to symptoms ranging from sneezing and coughing to rashes, swelling, vomiting, diarrhea, and in severe cases, anaphylaxis. IgE blood tests can assist healthcare providers in identifying allergies, but these tests must be interpreted alongside a comprehensive medical history.
In contrast, food intolerances do not engage the immune system in the same way allergies do. They arise when the body struggles to properly digest certain foods, resulting in primarily digestive symptoms. Common triggers for food intolerances include gluten, lactose, dairy, and sulfites; however, any food item can potentially cause an intolerance.
All home intolerance tests lack scientific validity and should be prohibited. None of the available home intolerance tests are accurate, evidence-based, or recognized by mainstream health organizations. The only reliable method to determine a food intolerance (or a non-IgE allergy) is through an elimination diet followed by reintroducing the eliminated foods to assess any correlation with symptoms.
Moreover, it should not be so simple to purchase an allergy test; although these tests are generally more scientifically sound, their quality varies, and even the most reputable tests can yield false positives if not conducted with a clinician’s guidance. This concern is particularly critical for children with eczema, according to Professor Helen Brough, a pediatric allergy consultant at Evelina London Children’s Hospital. She points out that in children with eczema, IgE tests often return slightly positive results for many foods due to elevated total IgE levels.
One of the most commonly bought food intolerance tests is the fingertip blood IgG test, which measures IgG (immunoglobulin G) levels in the blood. However, IgG is not indicative of food intolerances or allergies. As stated by the British Dietetics Association, “IgG antibodies are normal components of the immune response to infections and are produced in response to food intake.” We produce IgG antibodies in response to every food we consume.
When I spoke with Theresa MacPhail, a medical anthropologist and author of “Allergic: How Our Immune System Reacts to a Changing World,” she expressed strong criticism of IgG tests. “IgG tests are worthless,” she asserts. “Every person who drinks a glass of milk will generate an IgG antibody response because it is a foreign protein. People are spending hundreds of dollars to indicate their body is reacting to food, which is a normal response.”
