Onion

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What other names is Onion known by?

Allii Cepae Bulbus, Allium cepa, Cebolla, Échalote, Green Onion, Oignon, Oignon Vert, Onions, Palandu, Piyaj, Shallot.

What is Onion?

Onion is a plant. The bulb (rounded underground part) of the onion is used to make medicine.

Onion is used for treating digestion problems including loss of appetite, upset stomach, and gallbladder disorders; for treating heart and blood vessel problems including chest pain (angina) and high blood pressure; and for preventing "hardening of the arteries" (atherosclerosis). It is also used for treating sore mouth and throat, whooping cough, bronchitis, asthma, dehydration, intestinal gas, parasitic worms, and diabetes. Some people use it as a diuretic to increase urine output.

Onion is applied directly to the skin for insect bites, wounds, light burns, boils, warts, and bruises.

In foods, onion is used in many recipes.

In manufacturing, the oil is used to flavor foods.

Possibly Effective for...

  • Scarring. Most research suggests that applying onion extract, usually as a specific product containing heparin and allantoin (Contractubex), to the skin for 10 weeks to 6 months improves scar color and appearance, as well as pain and itching, in people with scars due to burns, tattoo removal, injuries, or surgical removement of tissue. However, using a specific product containing onion exract and allantoin (Mederma, Merz Pharmaceuticals) for 4-11 weeks does not seem to improve the appearance of new surgical scars.

Insufficient Evidence to Rate Effectiveness for...

More evidence is needed to rate the effectiveness of onion for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

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How does Onion work?

Onion might help reduce cholesterol levels, a risk factor for hardening of the arteries. There is some evidence that onion might also reduce lung tightness in people with asthma.

Are there safety concerns?

Onion is LIKELY SAFE when taken by mouth in amounts commonly found in food or when applied to the skin. It is POSSIBLY SAFE for most people when taken by mouth in larger amounts. Taking up to a maximum of 35 mg of the onion ingredient "diphenylamine" per day for several months seems to be safe.

Special Precautions & Warnings:

Pregnancy and breast-feeding: There is not enough reliable information about the safety of taking onion as a medicine if you are pregnant or breast-feeding. Stay on the safe side and avoid using onion in amounts larger than usual food amounts.

Bleeding disorder: Onion might slow blood clotting. There is concern that onion might increase the risk of bleeding when taken as a medicine. Don't use medicinal amounts of onion or onion extract if you have a bleeding disorder.

Diabetes: Onion might lower blood sugar. If you have diabetes and use onion in medicinal amounts, check your blood sugar carefully.

Surgery: Onion might slow blood clotting and lower blood sugar. In theory, onion might increase the risk for bleeding or interfere with blood sugar control during and after surgical procedures. Stop using onion as a medicine at least 2 weeks before a scheduled surgery.

Are there any interactions with medications?



Aspirin
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Some people are allergic to onions. Aspirin might increase your sensitivity to onions if you are allergic to onions. This has only been reported in one person. But to be on the safe side, if you are allergic to onions do not take aspirin and eat onions.



Lithium
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Onion might have an effect like a water pill or "diuretic." Taking onion might decrease how well the body gets rid of lithium. This could increase how much lithium is in the body and result in serious side effects. Talk with your healthcare provider before using this product if you are taking lithium. Your lithium dose might need to be changed.



Medications changed by the liver (Cytochrome P450 2E1 (CYP2E1) substrates)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Some medications are changed and broken down by the liver. Onion might slow down how quickly the liver breaks down some medications. Taking onion along with some medications that are broken down by the liver might increase the effects and side effects of some medications. Before taking onion, talk to your healthcare provider if you are taking any medications that are changed by the liver.

Medications that might be affected include acetaminophen, chlorzoxazone (Parafon Forte), ethanol, theophylline, and anesthetics such as enflurane (Ethrane), halothane (Fluothane), isoflurane (Forane), methoxyflurane (Penthrane), and others.



Medications for diabetes (Antidiabetes drugs)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Onion might decrease blood sugar. Diabetes medications are also used to lower blood sugar. Taking onion along with diabetes medications might cause your blood sugar to go too low. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.

Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.



Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Onion might slow blood clotting. Taking onion along with medications that also slow clotting might increase the chances of bruising and bleeding.

Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others.

Dosing considerations for Onion.

The appropriate dose of onion depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for onion. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

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You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Reviewed on 3/29/2011 12:35:40 PM

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