The common dandelion, enemy of suburban lawns, is an unusually nutritious food. Its leaves contain substantial levels of vitamins A, C, D, and B complex as well as iron, magnesium, zinc, potassium, manganese, copper, choline, calcium, boron, and silicon.

Worldwide, the root of the dandelion has been used for the treatment of a variety of liver and gallbladder problems. Other historical uses of the root and leaves include the treatment of breast diseases, water retention, digestive problems, joint pain, fever, and skin diseases.

The most active constituents in dandelion appear to be eudesmanolide and germacranolide, substances unique to this herb. Other ingredients include taraxol, taraxerol, and taraxasterol, along with stigmasterol, beta-sitosterol, caffeic acid, and p-hydroxyphenylacetic acid.1

Dandelion leaves are widely recommended as a food supplement for pregnant women because of the many nutrients they contain. The scientific basis for any other potential use of dandelion is scanty.

Dandelion leaves have been found to produce a mild diuretic effect,6 which has led to its proposed use for people who suffer from mild fluid retention, such as may occur in premenstrual syndrome (PMS). However, no double-blind, placebo-controlled studies have been reported on the effectiveness of dandelion for this purpose. (For information on double-blind studies, and why they are so important, see Why Does This Database Rely on Double-blind Studies?)

In the folk medicine of many countries, dandelion root is regarded as a "liver tonic," a substance believed to support the liver in an unspecified way. This led to its use for many illnesses traditionally believed to be caused by a "sluggish" or "congested" liver, including constipation, headaches, eye problems, gout, skin problems, fatigue, and boils. Building on this traditional thinking, some modern naturopathic physicians believe that dandelion can help detoxifyor clean out the liver and gallbladder.2This concept has led to the additional suggestion that dandelion can reduce the side effects of medications processed by the liver, as well as relieve symptoms of diseases in which impaired liver function plays a role. However, while preliminary studies do suggest that dandelion root stimulates the flow of bile,3,4,5 there is as yet no meaningful scientific evidence that this observed effect leads to any of the benefits described above.

Dandelion root is also used like other bitter herbs to improve appetite and treat minor digestive disorders. When dried and roasted, it is sometimes used as a coffee substitute. Finally, dandelion root is sometimes recommended for mild constipation.