How long can licorice root (glycyrrhizin) cause persistent hypertension after cessation?

Duration of Licorice-Induced Hypertension After Cessation

Blood pressure typically normalizes within 2 days to 3 weeks after stopping licorice consumption, though biochemical abnormalities may persist longer. 1

Timeline of Resolution

The evidence demonstrates variable recovery periods depending on the severity and duration of licorice exposure:

Rapid Resolution (Days)

• Blood pressure normalization: 2 days to 3 weeks is the most commonly reported timeframe 1, 2
• One case report documented BP returning to normal within 2 days of discontinuation in a patient who had used St. John's wort (though this was a different supplement, it demonstrates rapid resolution is possible) 1
• Another case showed BP normalization within 3 weeks alongside blood volume correction 3

Intermediate Resolution (Weeks to Months)

• Renal potassium wasting and hypertension can persist for 2 weeks even with potassium supplementation and spironolactone treatment 2
• Exchangeable sodium normalizes within 4 months, while plasma renin may take the same duration to recover 3
• Hypokalemia and metabolic alkalosis typically resolve within the first few weeks of cessation

Prolonged or Persistent Hypertension (Months to Permanent)

Critical caveat: One case report describes hypertension that remained elevated 6 months after licorice cessation, despite normalization of all laboratory parameters 4. This suggests that in patients with underlying genetic predisposition to hypertension (positive family history), licorice may trigger persistent hypertensive disease that does not resolve with cessation alone.

Mechanism Explaining Variable Duration

The persistence relates to the mineralocorticoid excess syndrome caused by glycyrrhetinic acid's inhibition of 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2):

• Cortisol accumulates at mineralocorticoid receptors causing sodium retention, hypervolemia, and hypertension 5
• The half-life and tissue accumulation of glycyrrhetinic acid metabolites determine recovery time
• Recent evidence identifies 3-epi-18β-glycyrrhetinic acid as a metabolite resistant to hepatic clearance, potentially prolonging effects 6
• Volume expansion and cardiac remodeling (left ventricular hypertrophy) may take months to reverse 7

Clinical Monitoring Recommendations

Monitor the following parameters after licorice cessation:

1. Blood pressure: Check weekly for the first month

   • Expect normalization within 2-3 weeks in most cases
   • If BP remains elevated beyond 3 weeks, consider underlying essential hypertension

2. Serum potassium: Recheck at 1-2 weeks

   • May require temporary potassium supplementation
   • Consider short-term mineralocorticoid receptor blocker (spironolactone) if severe 8

3. Renin and aldosterone: Recheck at 4-8 weeks if initially suppressed

   • These may remain suppressed for months 3

4. Sodium balance and volume status: Clinical assessment over 3-4 months

Important Clinical Pitfalls

• Do not assume permanent resolution: Patients with positive family history of hypertension may develop persistent disease triggered by licorice exposure 4
• Dose matters less than individual susceptibility: Recent evidence shows even 100 mg glycyrrhizic acid daily (previously considered safe) can significantly raise BP and suppress renin-aldosterone 9
• Age increases vulnerability: Elderly patients have age-related decline in 11β-HSD2 activity and reduced renal clearance, prolonging effects 6
• Intestinal microbiota variation: Individual gut bacteria profiles affect conversion to long-lasting metabolites 6

Management Algorithm

1. Immediate (Day 1): Stop all licorice-containing products
2. Week 1-2:
   • Supplement potassium if K+ <3.5 mmol/L
   • Consider spironolactone 25-50 mg daily for severe cases
   • Monitor BP 2-3 times weekly
3. Week 3-4:
   • Reassess BP and electrolytes
   • If normalized, continue monitoring monthly for 3 months
   • If persistent elevation, treat as essential hypertension
4. Month 4: Final assessment of renin-aldosterone axis recovery

The key clinical message: Most patients recover within 2-3 weeks, but a subset will have persistent hypertension requiring ongoing treatment, particularly those with genetic predisposition. 4