A patient seated in the chair before a blood draw
In person

Grapefruit Allergy (IgE)

IgE antibodies to grapefruit, measured from one blood draw.

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  • 2,000+ lab locations. Find one near you
  • Nothing due at the lab. FSA / HSA accepted
  • Ordered by a licensed clinician

At a glance

Collection
Blood draw
A standard blood draw at the lab.
Preparation
None
Nothing to do ahead of time. Water is fine.
Results
3 to 5 days
Typical turnaround after your visit.
Where
2,000+ lab locations
Nationwide, with nothing due at the lab.

About this test

This blood test measures IgE antibodies to grapefruit. People often check it after a reaction to grapefruit, or before seeing an allergist. A positive result shows sensitization, which does not by itself mean allergy. There is nothing to do ahead of your visit.

For adults 18 and older. Test availability varies by lab location.

Who should take this test?

This test is for adults who want to know whether they are sensitized to grapefruit, for example after a reaction to grapefruit, or ahead of an allergist visit.

Ask about this test

Not sure this is the right test?

AI-generated. For information only, not medical advice. Call 911 for an emergency.

What does this test measure?

Your grapefruit result can help you and an allergist see whether you are sensitized, one piece of information read alongside your symptoms and history.

Grapefruit-specific IgE (f209)
Specific IgE is an antibody the immune system can make against a single food. This marker measures IgE that recognizes grapefruit, a citrus fruit. A level above the lab’s reference range shows sensitization, which an allergist reads with your history.
Why it’s measured: Checks for IgE sensitization to grapefruit, often after a reaction to grapefruit.

How it works

  1. Step 1

    Order online

    Check out here. A licensed clinician in your state reviews your order and sends it to the lab.

  2. Step 2

    Visit a lab

    Bring a photo ID to any of 2,000+ lab locations. No fasting needed, and nothing is due at the lab.

  3. Step 3

    Get your results

    Results post to your account, usually in 3 to 5 days, each number next to the lab’s reference range.

Find a lab near you

Choose from 2,000+ lab locations nationwide. Your order works at any of them.

What your results tell you

Your result is reported as an IgE level in kU/L and compared with the lab’s reference range. A level above the range shows sensitization.

  • Your number next to the lab’s reference range
  • Explained in plain language
  • A licensed clinician reviews your order and, if appropriate, orders the test.
  • A lab report you can download and share

Decisions about eating grapefruit belong with an allergist or other healthcare provider, who reads this result with your history.

Clinical-grade testing, from the comfort of home.

From the lab to your report, every step of our process meets the gold standard in medical testing.

  • CLIA-certified labs

    Every lab we partner with is certified under the Clinical Laboratory Improvement Amendments, meeting both state and federal standards with regular independent inspections.

  • We protect your health data

    We protect your health data with encryption and do not sell it. Some results must be reported to public health authorities by law. See our Privacy Notice.

  • Rigorous quality assurance

    All partner labs run regular internal quality checks, participate in proficiency testing, and comply with federal and state lab regulations.

  • Clinician-reviewed reports

    Results are reviewed by an independent, licensed clinician.

Questions

Common questions.

Anything else, our care team answers by phone, text, or email.

Orange, lemon, lime, grapefruit, and mandarin are closely related citrus fruits, which is why they are often checked together.

This test measures IgE to grapefruit on its own. A positive result shows sensitization, not that you will react. An allergist reads it with your history before any decision about eating citrus.

Not on its own. A positive result means your immune system has made IgE to grapefruit, which is called sensitization. Many people who are sensitized have no symptoms when they are exposed.

A diagnosis of allergy is made by a healthcare provider who looks at your symptoms and history along with results like this one. A negative result also does not by itself mean you are not allergic.

No. This test is not for urgent reactions. If you have trouble breathing, swelling of the face or throat, or you faint after eating any food, call 911 or get emergency care right away. If you have a prescribed epinephrine auto-⁠injector, use it as directed.

Once a reaction has passed, an allergist or other healthcare provider can help you decide on next steps, including whether testing fits.

Both look for IgE sensitization. A skin test checks how your skin responds to a small amount of an allergen, while this test measures IgE to grapefruit in a blood sample. In many cases the two are considered comparable.

A blood test may be preferred in some situations, such as a widespread skin condition or recent use of medicines that affect skin tests. Don’t stop or change any medicine without talking with your healthcare provider.

Lab tests are informational and don’t diagnose conditions on their own. Available to adults 18 and older; test availability varies by lab location. A licensed clinician reviews your order and, if appropriate, orders the test. All testing is performed at CLIA-certified laboratories. Not for emergencies: if you think you may be having a medical emergency, call 911.