Dandelion

What side effects can dandelion cause?

Dandelion in food amounts is considered likely safe. Less is known about larger amounts. 1

Reported side effects include heartburn, stomach upset, skin rash and mild diarrhea at high intake. Allergic reactions can occur, and their frequency is not known. 2 3 4

Case reports describe low blood sugar after eating dandelion, bleeding of the bladder lining after a slimming product containing dandelion, and skin damage in fingers from oxalate build-up in a man with chronic kidney disease who drank 10 to 15 cups of dandelion tea daily for six months. 2

Allergy to daisy-family plants

People who are allergic to plants of the daisy family (Asteraceae) should not use dandelion medicines. The sesquiterpene lactones in dandelion are thought to cause allergic skin reactions, and anaphylaxis has been reported. 2 3 5

Topical dandelion may cause allergic reactions in people with eczema. Whether people sensitive to ragweed, chrysanthemums, marigolds or daisies also react to dandelion is uncertain. 1

Who should avoid dandelion preparations?

The EU monographs advise against dandelion preparations in bile duct obstruction, inflammation of the bile ducts, liver disease, gallstones and other biliary diseases, because dandelion may stimulate bile flow. The leaf monograph and the root and herb assessment also list active stomach ulcers. 3 4 5

Dandelion leaf should be avoided in kidney failure, diabetes or heart failure because its potassium could raise blood potassium too far. Root preparations are not recommended when a doctor has advised reduced fluid intake. 3 4

Use in children under 12 is not recommended because data are lacking. 3 4

Fever, painful urination, cramps or blood in the urine during use are reasons to see a doctor. 3 4

Can dandelion interact with medicines?

The EU monographs report no known interactions, but this reflects a lack of study rather than proof of safety. NCCIH notes theoretical reasons to suspect interactions with diabetes drugs, anticoagulants, antiplatelet drugs and water pills. 1 3 4

Pregnancy and breastfeeding

Little is known about the safety of dandelion in amounts above those in food during pregnancy or breastfeeding. Because safety has not been established, the EU monographs do not recommend dandelion preparations during pregnancy and breastfeeding. 1 3 4

Is long-term use a problem?

Using dehydrating detox products with ingredients such as dandelion for long periods and at high doses can increase the loss of sodium, potassium, calcium and magnesium, disturb electrolyte balance and weaken the effect of medicines. 8

There are no data on genotoxicity, cancer risk or reproductive toxicity of dandelion preparations, and no upper intake level has been set. 3 5