Hibiscus Extract
Research reviewed: Up until 03/2026
Hibiscus Extract (Hibiscus sabdariffa (Roselle)) is a dietary supplement with 10 published peer-reviewed studies involving 2,980 participants, researched for Blood Pressure Reduction, Cholesterol & Metabolic Health.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Blood Pressure Reduction
ModerateCholesterol & Metabolic Health
StrongResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Blood Pressure Reduction
To evaluate the efficacy of Hibiscus sabdariffa on blood pressure and cardiometabolic markers.
Study Type
Systematic review and meta-analysis of randomised controlled trials
Purpose
To evaluate the efficacy of Hibiscus sabdariffa on blood pressure and cardiometabolic markers.
Dose
Various Hibiscus preparations (250–1000 mg/day)
Participants
1,205 participants across 13 RCTs
Duration
4–12 weeks
Results
Hibiscus sabdariffa significantly reduced SBP by −7.6 mmHg and DBP by −3.5 mmHg vs control. Greater effects in hypertensive subjects. Lipid and glucose markers improved in some studies.
How They Measured It
Pooled SBP and DBP from 13 RCTs; secondary: lipids, glucose, CRP
To comprehensively assess the effects of Hibiscus sabdariffa on blood pressure and cardiometabolic markers.
Study Type
Systematic review and meta-analysis
Purpose
To comprehensively assess the effects of Hibiscus sabdariffa on blood pressure and cardiometabolic markers.
Dose
Various Hibiscus preparations
Participants
Multiple RCTs included
Duration
4–12 weeks
Results
Hibiscus significantly reduced SBP and DBP across all included studies. Pooled mean reductions of −5 to −10 mmHg in SBP were observed. Cardiometabolic improvements including LDL-C and fasting glucose also noted in subgroup analyses.
How They Measured It
Pooled SBP, DBP, lipids, glucose, BMI from eligible RCTs
To compare the antihypertensive effects of Hibiscus sabdariffa tea vs placebo in mild-to-moderate hypertension.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To compare the antihypertensive effects of Hibiscus sabdariffa tea vs placebo in mild-to-moderate hypertension.
Dose
Three 240 mL cups/day Hibiscus tea (1.25 g dried calyx/cup)
Participants
65 pre- and mildly hypertensive adults
Duration
6 weeks
Results
Hibiscus tea reduced SBP by 7.2 mmHg vs 1.3 mmHg for placebo (p<0.001). DBP reduced by 3.1 mmHg vs 0.5 mmHg (p=0.04). Greater reductions in subjects with highest baseline BP.
How They Measured It
Clinic SBP and DBP at 4, 8, and 12 weeks
To compare Hibiscus sabdariffa extract with captopril in hypertensive patients.
Study Type
Randomised, double-blind, controlled trial
Purpose
To compare Hibiscus sabdariffa extract with captopril in hypertensive patients.
Dose
250 mg Hibiscus extract capsule vs 25 mg captopril twice daily
Participants
193 hypertensive adults
Duration
4 weeks
Results
Hibiscus extract produced comparable antihypertensive effects to captopril (SBP −11.2 vs −11.5 mmHg). DBP reductions were similar. Acceptable safety profile. Mechanism linked to ACE inhibition and antioxidant activity.
How They Measured It
Blood pressure at 2 and 4 weeks; safety labs
To investigate Hibiscus sabdariffa as an adjunct for patients with uncontrolled hypertension on standard treatment.
Study Type
Randomised controlled pilot trial
Purpose
To investigate Hibiscus sabdariffa as an adjunct for patients with uncontrolled hypertension on standard treatment.
Dose
400 mg Hibiscus extract three times daily
Participants
42 patients with uncontrolled hypertension on medication
Duration
4 weeks
Results
Addition of Hibiscus to standard treatment provided further significant SBP reductions (−9.4 mmHg, p=0.02) and DBP (−5.1 mmHg, p=0.03). Well tolerated with no significant adverse events.
How They Measured It
24-hour ambulatory blood pressure, adverse events
Cholesterol & Metabolic Health
To assess Hibiscus sabdariffa on lipid profile and antioxidant status in hyperlipidaemic patients.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess Hibiscus sabdariffa on lipid profile and antioxidant status in hyperlipidaemic patients.
Dose
450 mg Hibiscus extract daily
Participants
60 hyperlipidaemic patients
Duration
4 weeks
Results
Hibiscus extract significantly reduced TC (−8.3%), LDL-C (−9.6%) and TG (−12.0%) vs placebo. HDL-C slightly increased. Oxidative stress markers (MDA) significantly reduced. Combined lipid-lowering and antioxidant effects confirmed.
How They Measured It
TC, LDL-C, HDL-C, TG, oxidative stress markers at baseline and after 4 weeks
To evaluate Hibiscus sabdariffa on blood pressure and endothelial function.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate Hibiscus sabdariffa on blood pressure and endothelial function.
Dose
300 mg Hibiscus extract standardised to anthocyanins
Participants
54 adults with pre-hypertension
Duration
6 weeks
Results
Hibiscus extract significantly improved endothelial function (FMD +2.1%) and reduced SBP (−5.8 mmHg) and DBP (−3.2 mmHg) vs placebo. Nitric oxide bioavailability increased, supporting vasodilatory mechanism.
How They Measured It
Flow-mediated dilation (FMD), blood pressure, nitric oxide levels
To assess the effect of Hibiscus sabdariffa tea on blood pressure in adults with metabolic syndrome.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess the effect of Hibiscus sabdariffa tea on blood pressure in adults with metabolic syndrome.
Dose
Hibiscus tea (3 x 250 mL cups/day)
Participants
75 adults with metabolic syndrome
Duration
8 weeks
Results
Hibiscus tea significantly reduced SBP and DBP. Fasting glucose and TG also improved. Weight and BMI unchanged. Multi-target effect particularly relevant for metabolic syndrome.
How They Measured It
SBP, DBP, fasting glucose, lipids, BMI
To provide a comprehensive overview of Hibiscus sabdariffa effects on cardiometabolic health across all clinical conditions.
Study Type
Systematic review and updated meta-analysis
Purpose
To provide a comprehensive overview of Hibiscus sabdariffa effects on cardiometabolic health across all clinical conditions.
Dose
Various (tea, extract, capsule)
Participants
1,797 participants across 26 primary RCTs
Duration
Various
Results
Hibiscus sabdariffa significantly reduced SBP and DBP across all populations. Lipid profiles improved particularly in dyslipidaemic subjects. No significant adverse effects. Evidence supports Hibiscus as a multi-target cardiometabolic supplement.
How They Measured It
Blood pressure, lipids, glucose, liver enzymes, body weight from RCTs
To evaluate the effect of Hibiscus sabdariffa on blood pressure in mildly hypertensive patients with type 2 diabetes.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate the effect of Hibiscus sabdariffa on blood pressure in mildly hypertensive patients with type 2 diabetes.
Dose
500 mg Hibiscus extract twice daily
Participants
70 adults with type 2 diabetes and mild hypertension
Duration
8 weeks
Results
Hibiscus extract significantly reduced SBP (−10.2 mmHg) and DBP (−5.8 mmHg) vs placebo. HbA1c improved modestly (−0.3%). LDL-C and TC were reduced. Well tolerated with no hypoglycaemic events.
How They Measured It
Clinic blood pressure, HbA1c, fasting glucose, lipid panel
Frequently Asked Questions
Common questions about Hibiscus Extract research
There are currently 10 peer-reviewed studies on Hibiscus Extract (Hibiscus sabdariffa (Roselle)), involving 2,980 total participants. Research covers Blood pressure reduction, Cholesterol management, Antioxidant support and 1 more areas. The overall evidence strength is rated as Very Strong.
The evidence is currently rated as "Very Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (10 human studies), and reported outcomes.
Hibiscus Extract has been researched for: Blood pressure reduction, Cholesterol management, Antioxidant support, Metabolic health. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 10 out of 10 studies are human trials. Human trials carry more weight in our evidence scoring system.
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