Effect of Hibiscus Extract on Metabolic Syndrome

Written by Chrystal Moulton, Science Writer. Overall results of this double-blind, placebo-controlled, randomized trial demonstrated no significant effect on HOMA-IR, fasting serum insulin and plasma glucose levels, nor HbA1C levels in the hibiscus group versus placebo.

hibiscus petals in black bowlMetabolic syndrome is a collection of chronic disorders which include obesity, dyslipidemia, hypertension, and diabetes. Lifestyle and dietary changes are required to improve health outcomes in those diagnosed with metabolic syndrome.1 Conventional treatment with prescription drugs for each associated ailment is common practice and sometimes leads to undesirable side effects. For roughly 12% to 31% of people globally who suffer from metabolic syndrome, supplementary or alternative methods also exist.1

Hibiscus sabdariffa L., commonly known as hibiscus, is rich in phenolic acids, flavonoids, and anthocyanins. Studies on the effectiveness of hibiscus have been mixed. Clinical trials demonstrated significant reduction in systolic blood pressure and fasting glucose levels.2,3 While some studies demonstrated no significant effects on body weight and others showed significant reduction in weight and abdominal obesity.4-6 Studies on the effect of hibiscus on serum lipids only showed significant reduction in LDL.2,3 In the current study, researchers investigated the effects of hibiscus extract on individuals with  metabolic syndrome in a double-blind, placebo-controlled, randomized trial.1

Two-hundred and forty-three participants, both men and women, between the ages 18-65 were recruited for this study. Eligible participants were required to have a waist circumference of 90cm for male participants and 80cm for female participants. They also needed to have 2 additional symptoms of metabolic syndrome, either:

  1. Fasting serum triglycerides >150mg/dL
  2. Fasting serum HDL <40mg/dL [men] or <50mg/dL [women]
  3. Blood pressure >130/85 mmHg
  4. Fasting glucose 100 -125 mg/dL

The study was 12 weeks. Hibiscus treatment was provided in a tablet which contained 125mg of aqueous extract for the calyx of Hibiscus sabdariffa L. The tablet provided 5.63mg/g of polyphenols per tablet. The placebo consisted of stearic acid, colloidal silicon dioxide, microcrystalline cellulose, and sodium carboxymethyl cellulose. Anthropometric measurements, blood pressure, along with blood samples were taken at baseline, week 6, and week 12. Participants were categorized into 3 groups based on BMI:

  1. Normal/overweight = 18.5 – 24.9 kg/m2
  2. Obesity I = 25.0 – 29.9 kg/m2
  3. Obesity II = >30 kg/m2

A 3-day food record (including 2 weekdays and 1 weekend) was recorded at baseline, week 6, and week 12. The primary outcomes of the study were changes in HOMA-IR, fasting plasma glucose, HbA1C, and insulin levels. Secondary outcomes were changes in BMI and waist circumference.

Of the 243 eligible participants recruited for the study, 108 were randomly allocated into each protocol in a 1:1 basis [treatment = 54, placebo = 54]. Data from a total of 84 participants were included in the analysis [treatment = 40, placebo = 44]. Researchers saw no significant differences between the groups as baseline in body weight, waist circumference, age, and sex. They also observed no difference in dietary intake and no serious adverse events throughout the study. Three participants in the placebo group reported an increase in urinary frequency and 1 participant in the hibiscus group reported increased bowel movements. No significant effect on liver function was observed in the hibiscus group. Overall results demonstrated no significant effect on HOMA-IR, fasting serum insulin and plasma glucose levels, nor HbA1C levels in the hibiscus group versus placebo. Further subgroup analysis showed no significant differences between individuals with pre-diabetes and metabolic syndrome. No significant differences were observed between the treatment and placebo in BMI and waist circumference at week 12. Furthermore, no significant differences were observed between placebo and hibiscus group in triglycerides, HDL, LDL, and total cholesterol at week 12, even after adjusting for physical activity, dietary intake, and additional subgroup analysis.

Within group analysis showed significant decreases in LDL, systolic and diastolic BP, HbA1C, and waist circumference at week 12 compared to baseline within the hibiscus group (P<0.05). They also observed a significant reduction in HbA1C, fasting plasma glucose, and systolic and diastolic blood pressure within the placebo group at week 12 compared to baseline (P<0.05). Furthermore, the reduction in systolic blood pressure was larger in the placebo group compared to the treatment group [placebo = -9.18 mmHg v. treatment = -5.20 mmHg]. However, in the treatment group researchers saw a larger reduction in diastolic blood pressure compared to the placebo group [treatment = -5.23 mmHg v. placebo = -4.77 mmHg]. Nonetheless, the overall effect of hibiscus on blood pressure was non-significant when compared to placebo. Additionally, sensitivity analysis confirmed no significant effect of hibiscus on lipid profile, glycemic markers, waist circumference, BMI, blood pressure, nor HOMA-IR compared to placebo.

Results from this study demonstrated no significant effect of hibiscus tablets (45.04 mg of total polyphenols per day) on lipid profile, glycemic markers, insulin resistance, blood pressure, and anthropometric measurements in individuals diagnosed with metabolic syndrome compared to placebo. Researchers, however, observed significant within group changes in blood pressure in both the placebo and treatment groups. Conversely, researchers observed significant within group changes in fasting glucose in the placebo group and LDL in the hibiscus group. Additional studies are needed to understand the effect of hibiscus intake on individuals with metabolic syndrome.

Source: Chaisungnern, Kanchaporn, Thanapoom Rattananupong, Rossukon Klinhom, Srisuphak Nanta, Kamonwan Banchuen, Arunporn Itharat, Pranporn Kuropakornpong, Thanan Supasiri, Preecha Nootim, and Wiroj Jiamjarasrangsi. “Efficacy of Hibiscus sabdariffa L. extract on metabolic parameters in participants with abdominal obesity and mild metabolic syndrome in Bangkok, Thailand: A double-blind, randomized, placebo-controlled trial.” Complementary Therapies in Medicine 91 (2025): 103185.

© 2025 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license

Click here to read the full text study.

Posted July 7, 2026.

Chrystal is a 2008 graduate of the University of Illinois at Chicago. She graduated with a bachelor’s in psychology with a focus on premedical studies and is a licensed project manager. She currently resides in Chicago.

References:

  1. Chaisungnern K, Rattananupong T, Klinhom R, et al. Efficacy of Hibiscus sabdariffa L. extract on metabolic parameters in participants with abdominal obesity and mild metabolic syndrome in Bangkok, Thailand: A double-blind, randomized, placebo-controlled trial. Complement Ther Med. Aug 2025;91:103185. doi:10.1016/j.ctim.2025.103185
  2. Ellis LR, Zulfiqar S, Holmes M, Marshall L, Dye L, Boesch C. A systematic review and meta-analysis of the effects of Hibiscus sabdariffa on blood pressure and cardiometabolic markers. Nutr Rev. May 9 2022;80(6):1723–1737. doi:10.1093/nutrit/nuab104
  3. Bule M, Albelbeisi AH, Nikfar S, Amini M, Abdollahi M. The antidiabetic and antilipidemic effects of Hibiscus sabdariffa: A systematic review and meta-analysis of randomized clinical trials. Food research international (Ottawa, Ont). Apr 2020;130:108980. doi:10.1016/j.foodres.2020.108980
  4. Han TS, Lean ME. A clinical perspective of obesity, metabolic syndrome and cardiovascular disease. JRSM Cardiovasc Dis. Jan–Dec 2016;5:2048004016633371. doi:10.1177/2048004016633371
  5. Al-Chalabi S, Syed AA, Kalra PA, Sinha S. Mechanistic Links between Central Obesity and Cardiorenal Metabolic Diseases. Cardiorenal Med. 2024;14(1):12–22. doi:10.1159/000535772
  6. Jeffery TD, Richardson ML. A review of the effectiveness of hibiscus for treatment of metabolic syndrome. J Ethnopharmacol. Apr 24 2021;270:113762. doi:10.1016/j.jep.2020.113762

 

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