Dandelion : Dosing and Safety

by MedlinePlus

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Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Standardization

Standardization involves measuring the amount of certain chemicals in products to try to make different preparations similar to each other. It is not always known if the chemicals being measured are the "active" ingredients. There are no standard or well-studied doses of dandelion, and many different doses are used traditionally. Safety of use beyond four months has not been evaluated.

Dandelion leaves are a source of vitamin A, containing up to 1400 IU per 100 grams.

Adults (18 years and older)

Dried root: Doses of two to eight grams taken by infusion or decoction have been used.

Leaf fluid extract: Doses of four to eight milliliters of a 1:1 extract in 25 percent alcohol have been used.

Root tincture: Doses of one or two teaspoons of a 1:5 tincture in 45 percent alcohol have been used.

Children (younger than 18 years)

There is not enough scientific research to recommend dandelion for use in children in amounts greater than found in food.

Safety

Allergies

Dandelion should be avoided by individuals with known allergy to dandelion, honey, chamomile, chrysanthemums, yarrow, feverfew or any members of the Asteraceae / Compositae plant families (ragweed, sunflower, daisies).

The most common type of allergy is dermatitis (skin inflammation) after direct skin contact with dandelion, which may include itching, rash, red/swollen or eczematous areas on the skin. Skin reactions are also reported in dogs. The main chemicals in dandelion responsible for allergic reactions are believed to be sesquiterpene lactones. Patch tests have been developed to assess for dandelion allergy.

Rhinoconjunctivitis and asthma have been reported after handling products such as birdfeed containing dandelion and other herbs, with reported positive skin tests for dandelion hypersensitivity.

Side Effects and Warnings

Dandelion has been well tolerated in a small number of available human studies. Safety of use beyond four months has not been evaluated.

The most common reported adverse effect is skin allergy, eczema, or increased sun sensitivity following direct contact.

According to traditional accounts, gastrointestinal symptoms may occur, including stomach discomfort, diarrhea and heartburn. There is a 1966 case of a patient who developed intestinal blockage from ingesting a large amount of dandelion greens three weeks after undergoing a stomach operation.

Parasitic infection due to ingestion of contaminated dandelion has been reported, affecting the liver and bile ducts, and characterized by fever, stomach upset, vomiting, loss of appetite, coughing and liver damage.

Dandelion may lower blood sugar levels based on one animal study, although another study notes no changes. Effects in humans are not known. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare professional, and medication adjustments may be necessary.

In theory, due to chemicals called coumarins found in dandelion leaf extracts, dandelion may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin, Advil) or naproxen (Naprosyn®, Aleve®).

Historically, dandelion is believed to possess diuretic (increased urination) properties and to lower blood potassium levels.

Dandelion may be prepared as a tincture containing high levels of alcohol. Tinctures should therefore be avoided during pregnancy or when driving or operating heavy machinery.

Pregnancy and Breastfeeding

Dandelion cannot be recommended during pregnancy and breast-feeding in amounts greater than found in foods, due to a lack of scientific information. Many tinctures contain high levels of alcohol and should be avoided during pregnancy.

About the Author

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