Dandelion supplements may add to the effects of diuretics or glucose-lowering medicine and may alter the metabolism of some prescription drugs. Much of the metabolism evidence is preclinical, but a transplant case report makes concentrated tea and extract use worth reviewing with a clinician.

Use with caution. Healthcare professional review recommended before use.

Contraindications

Known allergy to dandelion or other Asteraceae plants
Use of high-dose extracts without attention to blood sugar or diuretic effects

Cautions

Memorial Sloan Kettering notes that dandelion can cause heartburn, stomach upset, rash, mild diarrhea, and low blood sugar in susceptible users.
MSK also notes preclinical estrogenic activity and advises caution with concentrated supplement use when hormone sensitivity is a concern.
Large amounts of tea or extract are more likely to cause side effects or medication interactions than ordinary food use.

Drug Interactions

Drug Class / Substrate	Mechanism	Severity	Source
Diuretics	Dandelion may add to diuretic effects and increase urination.	Moderate	Memorial Sloan Kettering About Herbs
Insulin and other glucose-lowering medicines	Preclinical evidence suggests an additive glucose-lowering effect.	Uncertain	Memorial Sloan Kettering About Herbs
CYP1A2 and CYP3A4 substrate medicines	Laboratory and animal findings suggest dandelion may change drug metabolism. A case report described toxic immunosuppressant levels after a tea containing dandelion.	Moderate	Memorial Sloan Kettering About Herbs
UGT substrate medicines	Animal research suggests dandelion may alter glucuronidation and drug levels. Clinical relevance is not known.	Uncertain	Memorial Sloan Kettering About Herbs

This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before using herbal medicines, especially if you take prescription medications.