A SYSTEMATIC REVIEW ON THE EFFICACY, SIDE EFFECTS AND INTERACTIONS OF HIBISCUS SABDARIFFA ON BLOOD PRESSURE CONTROL

Background Control of hypertension remains a critical global health challenge, particularly in lower to middle-income nations where access is constrained. This is complicated by the side effects associated with conventional antihypertensive medications and the preference towards natural remedies. Hibiscus sabdariffa (HS) is emerging as a non-pharmacological medicinal solution given its cardio-protective and antihypertensive effects. Objective To systematically review the evidence for the efficacy, side effects and interactions of Hibiscus sabdariffa in blood pressure management among hypertensive adults. Methods A comprehensive search of major databases (PubMed, Academia, ResearchGate, AJOL and Google Scholar) was conducted, identifying randomized controlled studies, systematic reviews and review articles published from January 2015 up till September 2024 that assessed the antihypertensive effects of Hibiscus sabdariffa. The review was registered in PROSPERO (PROSPERO2025CRD420251007414) and followed the PRISMA guidelines. The study considered hypertensive adults aged 18 to 64 years and HS was tested as monotherapy. Risk of bias was evaluated using Cochrane Handbook guidelines. Results From the 884 articles retrieved, 18 studies matched the inclusion criteria and were reviewed. HS was shown to decrease both systolic and diastolic blood pressure across different ethnic groups and population centres. HS was shown to have equivalent efficacy as standard antihypertensive agents in comparative studies such as with hydrochlorothiazide and lisinopril. Additional findings suggest HS may also have lipid-lowering, antidiabetic, and organ-protective effects. Minimum adverse effects were reported and safety profile was generally favourable. The potential for herb-drug interaction with diuretics was noted but remains insufficiently explored. Conclusion Hibiscus sabdariffa shows promise as an effective, safe, and affordable alternative or adjunct in the management of mild to moderate hypertension. There is, however, a need for more standardized trials to establish dosage, treatment duration, and interactions with conventional antihypertensive medications.