You might want to consider a food sensitivity test if you struggle with symptoms like headaches, skin woes, or indigestion. Here's what to know before ordering one.

With all the health and diet content filling up your social media feeds, you may have noticed ads for at-home food sensitivity tests like Everlywell or Pinnertest, which claim to help identify underlying food intolerances in individuals. Dig deeper and you'll find testimonials from people who learned that almonds were causing their stomach pains or dairy was creating their skin issues. But are these test kits legitimate—and should you try one, too? Here's everything to know before diving in and ordering a test yourself.

How Food Sensitivity Tests Work

So what exactly are these food sensitivity tests? They're fairly easy at-home blood tests (for those who aren't squeamish, of course) that you can order online. When the kit arrives, you prick your finger, deposit drops of blood on a card, then send your blood sample in for results that usually arrive via email in a week or two. 

As for the science, "they use your blood to identify systemic antibodies called IgG (Immunoglobulin G) that develop when a certain food leaks out of a permeable gut or 'leaky gut' and into the bloodstream," says Jill Carnahan, MD, a functional medicine expert based in Colorado. "The body reacts with an inflammatory storm, which you may experience as stomach problems, joint pain, brain fog, acne, headaches, or skin issues."

A Food Intolerance Is Not a Food Allergy

Food intolerances are not the same thing as allergies, though. Allergies can result in anaphylactic reactions like hives, tongue and throat swelling, trouble breathing, and itchiness. 

"While an intolerance or sensitivity is uncomfortable, allergies can be life-threatening," explains Katherine Metzelaar, MSN, RDN, CD, a Seattle-based dietitian and certified intuitive eating counselor. "When you go to a trained doctor specializing in allergies, you will often have a skin-prick allergy test, a blood test, or both. These will measure IgE antibodies (Immunoglobulin E) that indicate an acute immune response and a true allergy."

There's Some Debate Around Them

If you're struggling with vague symptoms—like nagging indigestion or upset stomach; headaches, fatigue, and fogginess; or skin irritation and inflammation—an at-home blood test may seem like the perfect DIY solution for identifying the root causes of your woes. But the truth is, experts are divided on the accuracy of the results. 

The Cons...

"At home IgG food sensitivity tests are not currently recommended by the American Academy of Allergy Asthma and Immunology because the presence of the antibodies doesn't necessarily indicate a negative reaction to a food," says Claire Carlton, MS, RD, LD/N, a Honolulu–based registered dietitian nutritionist and digestive health expert. "These tests reflect the memory of our immune system and are often considered to actually be a marker of our tolerance—not intolerance—to these foods." 

Also, if you have a history of disordered eating or anxiety around food and dieting, Metzelaar warns that these kinds of tests can do more harm than good, exacerbating and reinforcing existing issues. 

The Pros...

That said, many swear by the accuracy of their at-home test results and have seen major lifestyle improvements by cutting out the offending foods or ingredients specified in their results.

"While there hasn't been a lot of validation studies for how accurate [food sensitivity tests] are, if you are experiencing inflammatory symptoms, it means you are not digesting certain foods properly. So these tests can be a helpful screening tool and the basis for a short-term elimination diet," says Christina Stapke, RDN, CD, a Seattle-based integrative and functional dietician. 

Healthy Tips for Managing a Food Sensitivity

Don't go crazy with it

"I recommend taking 30 days off from the high reactive foods, and then reintroducing them one by one, every two to three days—or even one a week—so you're better able to interpret how your body is reacting," says Dr. Carnahan. "For example, if you notice headaches or stomach aches after reintroducing gluten, there's your answer." She adds that, as an integrative doctor, it's beneficial for a patient to feel empowered to make their own decisions based on their symptoms. 

Take care of your gut

Remember, too, that the foods themselves, like gluten or dairy or chickpeas or egg whites, aren't the only potential issue. While a certain ingredient may be causing an inflammatory reaction, it's likely a weakened gut that's actually allowing the offending food to wreak havoc. Gut health maintenance is absolutely key. To improve your digestive health, Stapke recommends trying some daily stress relief in the form of yoga, meditation, or another form of me-time. "By reducing your cortisol levels, you give your digestive system a chance to rest, allowing your gut to produce higher secretions of the enzymes you need to break down all foods, which will prevent intestinal permeability," she says. 

Always eat a variety of foods

Stapke also recommends having a lot of variety in your diet. "If you eat the same thing every day, you'll have a higher chance of developing a sensitivity to it. While it's fine to make a big batch of stew to enjoy all week, you don't want to be eating cauliflower or lentils every single day because, ultimately, your body may literally get sick of it." 

Consult a medical professional

Of course, if your nagging or chronic symptoms are not subsiding, or you're having more allergic reactions when you eat certain foods, see your primary care physician or other medical professional for a full diagnosis and treatment plan.