A study published in the Journal of Ethnopharmacology showed hibiscus tea reduced both systolic and diastolic blood pressure in study participants by over 10 percent, after 12 days of treatment.
References
- The Effect of Sour Tea (Hibiscus Sabdariffa) on Essential Hypertension; Journal of Ethnopharmacology Volume 65, Issue 3; M. Haji Farajia, A. H. Haji Tarkhani; June 2009
