Health Guide


What is it?

Onion is a food substance that may be used to treat coronary heart disease, cancer, hyperglycemia (high blood sugar), and blot clots.

Other names for onion include: Allium cepa, Kuechenzwiebel, zwiebel, Allium fistulosum, or Welsh onion.

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 breastfeeding
  • have any other health problems, such as high blood pressure or heart or blood vessel disease


Talk with your caregiver about how much onion you should take. The amount depends on the strength of the medicine and the reason you are taking onion. 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 Throw away medicine that is out of date or that you do not need.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 Interaction: Do not take onion without talking to your doctor first if you are taking:

  • Blood thinning medicine (examples: warfarin (Coumadin(R)) (5)


  • Before taking onion, tell your doctor if you are pregnant or breastfeeding

Side Effects:

Stop taking your medicine right away and talk to your doctor if you have any of the following side effects. Your medicine may be causing these symptoms which may mean you are allergic to it.

  • Breathing problems or tightness in your throat or chest
  • Chest pain
  • Skin hives, rash, or itchy or swollen skin

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.

  • Your breast fed infant may develop colic if you eat onions (4)


1. Blumenthal M, Busse M, Goldberg A et al: Onion. In: The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. The American Botanical Council, Austin, TX; 1998.

2. Sharma KK, Gupta RK, Gupta S et al: Antihyperglycemic effect of onion: effect on fasting blood sugar and induced hyperglycemia in man. Indian J Med Res 1977, 65(3):422-429.

3. Mathew PT & Augusti KT: Hypoglycaemig effects of onion, Allium cepa Linn, on diabetes mellitus - a preliminary report. Indian J Physiol Pharmacol 1975; 19(4):213-217.

4. Lust KD, Brown JE & Thomas W: Maternal intake of cruciferous vegetables and other foods and symptoms in exclusively breast-fed infants. J Am Diet Assoc 1996; 96(1):46-48.

5. Product Information: COUMADIN(R) oral tablets, IV injection, warfarin sodium oral tablets, IV injection. Bristol-Myers Squibb Company, Princeton, NJ, 2007.

Last Updated: 7/4/2018
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