Dandelion: digestion, diuretic effect, forms and precautions — what does the evidence say?

EMA lists traditional use of dandelion root for mild digestive symptoms such as fullness, flatulence and slow digestion, and for temporary loss of appetite. It also lists traditional use to increase urine and support urinary flushing in minor complaints.

A review of gastrointestinal research describes laboratory and animal findings for different constituents and preparations. It also states that clinical research on efficacy, bioavailability and safety is still needed.

A pilot trial studied a hydroethanolic leaf extract in 17 volunteers. With 8 ml three times in one day, urination frequency increased after the first dose and the urine-to-fluid intake ratio increased after the second. The third dose changed none of the measured parameters.

Adequate fluid intake is needed when a preparation is used for urinary flushing, unless a doctor has advised fluid restriction. More urination does not automatically detoxify the body or treat a urinary infection.

Monographs distinguish dried root for decoction, fresh-root juice, liquid extracts, tincture, and root with aerial parts as tea or solid/liquid preparations. Taraxacum species, plant parts and preparations differ; results do not automatically transfer from one form to another.

Root preparations are contraindicated with bile-duct obstruction, cholangitis, liver disease, gallstones or other biliary disease. A monograph on root with aerial parts also advises avoiding use with renal failure, diabetes or heart failure, partly because of possible hyperkalaemia. Allergy to Asteraceae is possible.

Fever, painful or spasmodic urination, difficulty urinating or blood in urine require medical advice. Digestive symptoms that persist for more than two weeks or worsen also need assessment.