Hibiscus is a tart, caffeine-free plant drink that modestly lowers elevated blood pressure and may slightly improve "bad" cholesterol and fasting blood sugar. Benefits are largest for those with high-normal numbers and depend on continued daily intake. Evidence is consistent in direction but mixed in strength. Avoid during pregnancy and alongside blood-pressure drugs. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Systolic / Diastolic Blood Pressure | ~110–120 / 70–80 mmHg | Primary outcome of interest |
| LDL Cholesterol | < 100 mg/dL | Tracks the lipid benefit |
| Fasting Plasma Glucose | 70–90 mg/dL | Detects the modest glucose effect |
| HbA1c | < 5.4% (functional); < 5.7% conventional | Reflects average glucose over ~3 months |
| AST (aspartate aminotransferase) | ~10–26 U/L (functional) | Screens for the minor liver-enzyme signal |
| Serum Potassium | 4.0–4.5 mmol/L | Reassurance given diuretic activity |
Cadence: At 4 weeks after starting, again at 8–12 weeks, then every 6–12 months with stable long-term use; more frequently when combined with antihypertensive or antidiabetic medication.