Food and medicine interaction
Black licorice and licorice root (glycyrrhizin) and blood pressure medicines and diuretics (water pills)
EstablishedEvidence level: established. Shown in drug labeling or in controlled studies in people.
Last reviewed
What can happen
Regular licorice raises blood pressure and lowers potassium, working against blood pressure treatment. Reviews of interaction reports include low potassium after licorice combined with antihypertensives.
- Why it happens
- Glycyrrhizin makes the kidneys hold on to sodium and lose potassium, mimicking excess aldosterone.
- At ordinary food amounts
- Candy amounts can matter. A meta-analysis of 18 studies found products giving at least 100 mg of glycyrrhizic acid a day raised blood pressure and lowered potassium, even at modest doses. Many licorice-flavored sweets use anise instead; check the label for licorice extract.
What to do
If you take blood pressure medicine or a diuretic, ask your prescriber before eating licorice candy or taking licorice root regularly. Products labeled deglycyrrhizinated (DGL) have the glycyrrhizin removed.
Never stop or change a prescribed medicine without talking to the prescriber.
Common questions
Can I have black licorice and licorice root (glycyrrhizin) while taking antihypertensives and diuretics?
If you take blood pressure medicine or a diuretic, ask your prescriber before eating licorice candy or taking licorice root regularly. Products labeled deglycyrrhizinated (DGL) have the glycyrrhizin removed. Candy amounts can matter. A meta-analysis of 18 studies found products giving at least 100 mg of glycyrrhizic acid a day raised blood pressure and lowered potassium, even at modest doses. Many licorice-flavored sweets use anise instead; check the label for licorice extract.
Sources
- Penninkilampi R, et al. The association between consistent licorice ingestion, hypertension and hypokalaemia: a systematic review and meta-analysis. J Hum Hypertens. 2017. PMID 28660884.
- Izzo AA, et al. Cardiovascular pharmacotherapy and herbal medicines: the risk of drug interaction. Int J Cardiol. 2005. PMID 15676159.
- National Center for Complementary and Integrative Health. Licorice Root: Usefulness and Safety.