If certain foods leave you bloated, tired or foggy, you've probably seen two very different kinds of at-home tests online: ones that use a few strands of hair, and finger-prick blood kits. Add in your primary care doctor and an allergist, and it's easy to lose track of which test answers which question. This guide compares hair and blood testing side by side for US readers: what each one looks at, what it usually costs, and where an at-home food sensitivity test can fit in.
Start with the question you're asking: allergy or sensitivity?
A food allergy involves the immune system, usually comes on quickly (often within minutes) and can be serious. A food sensitivity or intolerance tends to build more slowly, often hours after eating, and shows up as everyday discomfort: bloating, gas, stomach pain, diarrhea, headaches, tiredness or brain fog.
True allergies are only around 10% of reactions to food. Intolerances and sensitivities are the main cause of the everyday discomfort people put up with, which is why so many people look into sensitivities first. Our symptoms page lists common signs.
In the US, the FDA lists nine major food allergens that must be declared on packaged food: milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame. Checking labels for these is a good habit whichever route you take.
If you ever have swelling of the lips, tongue or throat, trouble breathing, or feel faint after eating, that's an emergency: call 911.
The blood route: what each blood test checks
"Blood test" can mean several different things, so it helps to know which one you're looking at.
- IgE blood testing (through your doctor or an allergist). This looks for IgE antibodies, the antibodies involved in true food allergies. It's ordered by a clinician and the results are read alongside your history.
- Celiac disease blood tests (through your primary care doctor). Celiac disease is an autoimmune condition, not an intolerance, but the symptoms overlap. The NIDDK explains how doctors test for celiac disease. Keep eating gluten until you've been tested, because cutting it out first can affect the results.
- Mail-in IgG finger-prick kits (bought online). These measure IgG antibodies to a panel of foods. You prick your finger at home, fill a small card or tube and mail it back. Panels vary from brand to brand, so check how many foods are included.
For lactose, a different kind of check is often used: your doctor may suggest a short trial without dairy, or a hydrogen breath test.
How allergists test
If your doctor thinks you might have a true food allergy, they may refer you to a board-certified allergist. Allergists generally use skin-prick testing and IgE blood testing, and sometimes a supervised oral food challenge, where you eat small, increasing amounts of a food under medical supervision. These methods are designed for allergies, so they aren't used to look for everyday sensitivities.
The hair route: what a hair sensitivity test checks
A hair sensitivity test works differently from any of the blood tests above. It doesn't measure antibodies. You send a small hair sample, and our testing team uses bioresonance to look for potential sensitivity patterns across hundreds of food and non-food items, such as additives, metals and environmental items. Our guide to how hair sensitivity testing works explains the method in more detail.
In the US, our tests come with digital instructions: you get a link by email, cut a small hair sample and mail it to us in your own envelope. Here's what you're ordering with digital instructions and what happens after you send your hair sample. Results arrive in 5–7 working days once your sample is received.
If you want to start with the widest range of items, the Optimum Sensitivity Test covers 1,600. If you'd rather start smaller, the Individual Sensitivity Test covers 600.
Hair vs. blood at a glance
| At-home hair sensitivity test | Allergist IgE testing | Mail-in IgG finger-prick kit | |
|---|---|---|---|
| What it looks at | Potential sensitivity patterns, using bioresonance | IgE antibodies linked to true allergies | IgG antibodies to a panel of foods |
| Sample | A few strands of hair | Skin prick and/or blood draw | Finger-prick blood |
| Where | At home, mailed in | Clinic visit | At home, mailed in |
| Items covered | 600, 1,000 or 1,600 food and non-food items | Foods your allergist chooses from your history | Depends on the kit's food panel |
| How it's paid for | Out of pocket, from US$44.95 | Usually billed through your health insurance | Usually out of pocket; prices vary by brand and panel |
What it costs in the US
Allergist and doctor visits. These are usually billed through your health insurance, so what you pay depends on your plan's copay, deductible and coinsurance, and on whether you need a referral from your primary care doctor first. It's worth calling your insurer before you book.
Mail-in blood kits. These are usually paid out of pocket. Prices vary by brand and by how many foods are on the panel, so compare what's included, and check whether there are extra fees.
Our hair sensitivity tests. These are paid out of pocket. If you hope to use an HSA or FSA, check with your plan administrator first. Here are our current US prices:
| Test | Items checked | 1 person | 2 people | 4 people |
|---|---|---|---|---|
| Individual Sensitivity Test | 600 | US$44.95 | n/a | n/a |
| Ultimate Individual Test | 1,000 | US$49.95 | US$89.95 | US$149.95 |
| Optimum Sensitivity Test | 1,600 | US$59.95 | US$99.95 | US$159.95 |
Prices shown are for US orders on October 27, 2026, with digital instructions. Your current price is on each test page. Every hair sensitivity test comes with our 30-day 100% money-back guarantee.
Not sure which level suits you? Our guide to comparing food sensitivity tests explains the differences, so we won't repeat it here. Testing the whole household? The Ultimate Individual Test and the Optimum test both come in 2- and 4-person versions, which work out cheaper per person.
A sensible order of steps
Here's how many of our US customers combine the routes:
- See your primary care doctor to rule out anything that needs medical attention, including celiac disease (keep eating gluten until you've been tested).
- Ask about an allergist referral if you've had fast reactions such as hives or swelling.
- Start a food and symptom diary straight away. Our free food and symptom diary template makes this easy.
- Take an at-home food sensitivity test if you'd like a shortlist of potential sensitivities to explore.
- Compare your results with your diary and look for foods that appear in both.
- Trial changes one food at a time, ideally with a registered dietitian nutritionist (RDN). You can find an RDN near you and filter by insurance.
Common questions
Is a hair test or a blood test better for food sensitivities? They look at different things. Allergist IgE testing is for true allergies. Mail-in IgG kits measure IgG antibodies to foods. A hair sensitivity test uses bioresonance to look for potential sensitivity patterns across food and non-food items, without a needle. Many people use a hair test as a starting point alongside a food diary.
Does insurance cover at-home food sensitivity tests? At-home tests are usually paid out of pocket. Check with your insurer or plan administrator if you'd like to know about HSA or FSA use.
How long do results take? Results arrive in 5–7 working days once your sample is received. Mailing time is separate.
What if I'm not happy? We offer a 30-day 100% money-back guarantee on hair sensitivity tests.
Ready to start? Compare our sensitivity tests and choose the one that suits you.
About our tests
Test My Food Sensitivity has offered at-home hair sensitivity tests since 2008. Our tests use bioresonance, which looks at energetic frequencies from a hair sample to identify potential sensitivity patterns. They don't measure immune antibodies (IgE or IgG) and they aren't a medical diagnosis. Use your personalized results as a starting point for exploration, and talk to your primary care doctor or a registered dietitian nutritionist before making big or long-term changes to your diet.
