Health Guide

Grapefruit seed extract

What is it?

Grapefruit seed extract has been used to fight bacteria, viruses, and parasites, and to strengthen the immune system. As a preservative, it has been added to cosmetics and hair care products. Other uses for grapefruit seed extract include as a mouthwash and throat gargle, acne skin cleanser, and disinfectant.

Other names for grapefruit seed extract include: Citrus grandis, Citrus paradisi macfad, and Rutaceae.

Ask your doctor, nurse, or pharmacist if you need more information about this medicine or if any information in this leaflet concerns you.

Before Using:

Tell your doctor if you

  • are taking medicine or are allergic to any medicine (prescription or over-the-counter (OTC) or dietary supplement)
  • are pregnant or plan to become pregnant while using this medicine
  • are breast feeding
  • have any other health problems, such as high blood pressure or heart or blood vessel disease


Talk with your caregiver about how much grapefruit seed extract you should take. The amount depends on the strength of the medicine and the reason you are taking grapefruit seed extract. If you are using this medicine without instructions from your caregiver, follow the directions on the medicine bottle. Do not take more medicine or take it more often than the directions tell you to.

To store this medicine:

Keep all medicine locked up and away from children. Store medicine away from heat and direct light. Do not store your medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down and not work the way it should work. Throw away medicine that is out of date or that you do not need. Never share your medicine with others.

Drug and Food Interactions:

Do not take grapefruit seed extract without talking to your doctor first if you are taking:

  • Medicines used after organ transplant (examples: cyclosporine (Neoral(R), Sandimmune(R)) (1)


  • Before taking grapefruit seed extract, tell your doctor if you are pregnant or breast feeding.
  • Before taking grapefruit seed extract, tell your doctor if you are taking any other medicines.

Side Effects:

Call your doctor right away if you have any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing, or rash.

Other Side Effects:

You may have the following side effects, but this medicine may also cause other side effects. Tell your doctor if you have side effects that you think are caused by this medicine.

  • nausea and vomiting (2)
  • swollen or painful tongue (liquid drops) (2)
  • mouth, throat, or stomach burns (liquid drops) (2)


1. Hou YC, Hsiu SL, Tsao CW et al: Acute intoxication of cyclosporin caused by coadministration of decoctions of the fruits of Citrus aurantium and the Pericarps of Citrus grandis. Planta Med 2000; 66(7):653-655.

2. Holmgren A & Sjoberg G: Grapefruit seed extract-case reports. In: Clinical Toxicology, Abstracts of the European Association of Poison Centres and Clinical Toxicologists 19th International Congress 1999; 37:353-418.

3. Resnick SK: Grapefruit seed extract, natural antibiotic. Natural Health 1992; Jan-Feb:37-38.

4. von Woedtke T, Schluter B, Pflegel P et al: Aspects of the antimicrobial efficacy of grapefruit seed extract and its relation to preservative substances contained. Pharmazie 1999; 54:452-456.

Last Updated: 7/4/2018
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