MODERATE — Monitor Closely
🟡 CAUTION — Licorice root causes pseudoaldosteronism (sodium retention, potassium wasting, blood pressure elevation) that directly opposes Guanfacine. Avoid licorice root if taking antihypertensive medications, or use DGL (deglycyrrhizinated licorice) which lacks this effect.
Evidence level: STRONG
Licorice root elevates blood pressure by forcing sodium retention and potassium excretion through pseudoaldosteronism. Guanfacine reduces blood pressure by activating alpha-2A receptors in the prefrontal cortex to lower sympathetic outflow. These two drugs work on completely separate systems, so Guanfacine cannot prevent licorice from raising your blood pressure.
Glycyrrhizin in licorice root inhibits 11-beta-hydroxysteroid dehydrogenase type 2, causing cortisol to activate mineralocorticoid receptors (pseudoaldosteronism). This causes sodium retention, potassium wasting, and blood pressure elevation — directly opposing the antihypertensive action of Guanfacine.
Avoid licorice root if you take Guanfacine. Guanfacine is widely prescribed for ADHD (especially in children and teens) in its extended-release form (Intuniv), not just for blood pressure. If your child takes Guanfacine for ADHD, ensure they avoid licorice-containing supplements, candies, and herbal teas. Licorice-induced blood pressure changes can cause headaches and dizziness that mimic ADHD medication side effects, masking the real problem. DGL licorice is safe.
Be consistent with how you take Guanfacine relative to meals — take it with food or without food consistently each day. Licorice Root — sudden large changes in diet composition can affect how your body processes many medications. Grapefruit, leafy greens, and high-fiber foods are the most common food-drug interaction culprits.
Higher risk for: elderly, those with liver or kidney impairment, polypharmacy (5+ medications), recent medication changes, or those with multiple chronic conditions. Consult your pharmacist for specific risk factors.
Rising blood pressure despite medication, headache, swelling in legs/ankles, muscle weakness or cramps, irregular heartbeat (from low potassium).
No urgent need to discuss, but always keep your doctor informed of your full supplement and medication list. An up-to-date list helps them make the best treatment decisions.
Adjust the timing or quantity of Licorice Root relative to your medication. Maintain consistent daily intake rather than large sporadic amounts. Your pharmacist can advise on specific timing windows.
Licorice root elevates blood pressure by forcing sodium retention and potassium excretion through pseudoaldosteronism. Guanfacine reduces blood pressure by activating alpha-2A receptors in the prefrontal cortex to lower sympathetic outflow. These two drugs work on completely separate systems, so Guanfacine cannot prevent licorice from raising your blood pressure.
Be consistent with how you take Guanfacine relative to meals — take it with food or without food consistently each day. Licorice Root — sudden large changes in diet composition can affect how your body processes many medications. Grapefruit, leafy greens, and high-fiber foods are the most common food-drug interaction culprits.
Rising blood pressure despite medication, headache, swelling in legs/ankles, muscle weakness or cramps, irregular heartbeat (from low potassium).
Adjust the timing or quantity of Licorice Root relative to your medication. Maintain consistent daily intake rather than large sporadic amounts. Your pharmacist can advise on specific timing windows.
No urgent need to discuss, but always keep your doctor informed of your full supplement and medication list. An up-to-date list helps them make the best treatment decisions.
Or browse the full interaction database (121,000+ pairs).