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Scientific Name(s): Hibiscus sabdariffa L.
Common Name(s): Hibiscus, Jamaica sorrel, Karkade, Karkadi, Red sorrel, Red tea, Rosa de Jamaica, Rosella, Roselle, Soborodo, Sour tea, Zobo drink

Medically reviewed by Last updated on May 21, 2021.

Clinical Overview


The leaves and calyces have been used as food and the flowers steeped for tea. Hibiscus has been used in folk medicine as a diuretic and mild laxative, as well as in treating cancer and cardiac and nerve diseases. Although information is limited, the potential for hibiscus use in treating hypertension and cancer, as well as for its lipid-lowering and renal effects, are being investigated.


In trials investigating the hypotensive effect of hibiscus, daily dosages of dry calyx 10 g (approximately anthocyanin 9.6 mg) as an infusion in water, and total anthocyanin 250 mg per dose have been used for 4 weeks. Alternatively, doses of H. sabdariffa 3.75 g/day to 2 spoonfuls or 100 mg of aqueous H. sabdariffa for a duration of 15 days to 6 weeks was identified in a 2014 meta-analysis of trials investigating blood pressure effects.


Contraindications have not been identified.


Documented adverse reactions. Avoid use.


Studies in healthy volunteers have shown altered chloroquine, acetaminophen, and diclofenac pharmacokinetics. The clinical effects of these interactions have not been evaluated.

Adverse Reactions

Preparations used in clinical trials were well tolerated.


Data are limited.

Scientific Family

  • Malvaceae (mallow)


H. sabdariffa is native to Central and West Africa, but grows throughout many tropical areas. This annual herb grows to 1.5 m or higher and produces elegant red flowers. The flowers (calyx and bract portions) are collected when slightly immature. The major producing countries are Jamaica and Mexico.1, 2, 3 A related species, Hibiscus rosa-sinensis (rose of Sharon), is widely cultivated for ornamental planting.


Hibiscus has a long history of use in Africa and neighboring tropical countries for many conditions, including hypertension, liver diseases, cancer, constipation, and fever. The fleshy red calyx is used in the preparation of jams, jellies, drinks, and cold and warm teas. The plant is also widely used in Egypt, Iran, and Thailand, as well as in Western countries. Hibiscus flowers often are found as components of herbal tea mixtures2, 3, 4, 5, 6; it is a major component of the popular herbal blend Red Zinger.


A large variety of compounds have been isolated from the hibiscus plant.2 As expected from their vivid color, hibiscus flowers contain various polyphenols, including anthocyanins, proanthocyanidins, flavonols, and other pigments.2, 7, 8, 9 Oxalic, malic, citric, stearic, and tartaric acids have been identified and are, along with 15% to 28% of hibiscic or hibiscus acid (lactone of hydroxycitric acid), most likely contribute to the tartness of the herb and its teas. Roselle seed oil contains more than 25 volatile compounds, mainly unsaturated hydrocarbons, aldehydes, and alcohols.2, 5 The oil is rich in gamma tocopherol.10 The saturated fatty acids (palmitic and stearic) and unsaturated fatty acids (oleic and linoleic) contents have been described.2, 5 The seeds and flowers contain high amounts of protein and crude oil, ash, and carbohydrate. High amounts of arginine, aspartic acid, and glutamic acid were found in the protein isolated from the seed.5, 9

Uses and Pharmacology


Numerous in vitro experiments have evaluated the effects of hibiscus flower or anthocyanin extracts against various cancer cell lines. Proposed mechanisms of action focus on antioxidant activity and the ability to induce apoptosis.2, 11, 12, 13, 14, 15, 16, 17

Animal data

Studies in rats have evaluated effects against liver, oral, colon, bladder, and stomach cancers.2

Clinical data

Clinical trials evaluating the use of hibiscus as a chemopreventive or therapeutic agent are lacking. In vitro experiments have shown apoptotic activity against human leukemia (HL-60),2, 12, 13, 14 gastric,15 and cervical17 cell lines.


In vitro experiments attribute lipid-lowering action to inhibition of low-density lipoprotein (LDL) oxidation.2, 18, 19, 20, 21, 22, 23, 24

Animal data

Studies in hyperlipidemic mice, rats, and rabbits have evaluated the effects of dried calyx extracts on the lipid profile. Although not consistently, the experiments largely demonstrate decreases in serum cholesterol, triglycerides, and LDL, with no effect on high-density lipoprotein (HDL).2, 18, 19, 20, 21, 22, 23, 24

Additional effects observed in these experiments include a hypoglycemic effect24 and antiatherosclerotic (histological) action.23

Clinical data

Clinical trials evaluating the hypolipidemic effect of hibiscus are lacking.


Animal data

Experiments in animals have shown aqueous and methanol extracts of the plant calyces have hypertensive actions.2, 25, 26, 27 Suggested mechanisms of action include inhibition of angiotensin I converting enzyme,2 partial cholinergic and/or histaminic mechanisms,2 vasodilation,26 and natriuric effects.27

Clinical data

A number of small clinical trials evaluated the effect of aqueous calyx extracts on blood pressure.2 Methods of randomization and blinding are not clearly described in the studies. In addition, differences in baseline parameters among study groups and lack of intention-to-treat analyses limit confidence in the findings.6, 28, 29

A dose-dependent decrease in systolic and diastolic blood pressure has been demonstrated for aqueous preparations of the hibiscus calyx comparable in effect to that of captopril and lisinopril. A natriuric effect was also observed in these studies.28, 29 In an earlier trial, patients with essential, but untreated, hypertension demonstrated a decrease in blood pressure with sour tea therapy. Their hypertensive state returned on cessation of therapy.6 A systematic review and meta-analysis of randomized placebo-controlled parallel or crossover trials published through June 2014 that evaluated the effect of H. sabdariffa (sour tea) on blood pressure identified 5 trials (N = 390) that met inclusion criteria; drug-comparator trials were excluded. Doses ranged from 3.75 g/day to 2 spoonfuls or 100 mg of aqueous H. sabdariffa for a duration of 15 days to 6 weeks; 1 trial included healthy volunteers as well as patients with metabolic syndrome. Pooled estimates revealed a significant effect of sour tea on systolic blood pressure (SBP) and diastolic blood pressure (DPB), and fixed-effect meta-regression found a significant inverse relationship between baseline blood pressure and effect (P = 0.0005 for SBP and P = 0.002 for DBP). No adverse effects were observed.43

Renal system

Animal data

Studies in rats suggest a uricosuric effect of the calyx extract.2

Clinical data

Conflicting clinical data exist regarding the effect of hibiscus extracts on the excretion of uric acid.2, 30, 31 The study parameters vary with respect to dose, preparation used, and study population, making conclusions difficult. Increased urinary sodium excretion has been demonstrated in trials evaluating hypotensive effects of hibiscus extracts.2, 28, 29

Other effects

Aqueous hibiscus extracts have shown inhibitory effects on the contractility of various muscle tissues, including uterine.2, 32 In other experiments, extracts have demonstrated a mild cathartic activity in rats4 in the absence of increased peristalsis, as well as stimulatory effects in frogs' abdominal/rectal tissues.2

Roselle tea extract exhibited high inhibition against porcine pancreatic alpha-amylase. Proposed uses for this inhibition include decreased glucose absorption and inhibition of HIV replication.33

Protective effects of the plant extracts on induced testicular and hepatic toxicity have been demonstrated in animals and are attributed to antioxidant action.34, 35, 36


In trials investigating the hypotensive effect of hibiscus, daily dosages of dry calyx 10 g (equivalent to anthocyanin 9.6 mg) as an infusion in water28 and total anthocyanin 250 mg per dose29 have been used for 4 weeks. The kinetics and urinary excretion of the anthocyanin glycosides have been studied in healthy volunteers. An estimated half-life of 2.6 hours and a maximum excretion at 1.5 to 2 hours was noted.37 Alternatively, doses of H. sabdariffa of 3.75 g/day to 2 spoonfuls or 100 mg of aqueous H. sabdariffa for a duration of 15 days to 6 weeks was identified in a 2014 meta-analysis of trials investigating blood pressure effects.43

Pregnancy / Lactation

Documented adverse reactions. Avoid use.2, 32, 38


Studies in healthy volunteers have shown altered chloroquine,39 acetaminophen,2 and diclofenac40 pharmacokinetics with concomitant consumption of hibiscus preparations. The clinical effects of these interactions have not been evaluated.

Digoxin lab assay

Hibiscus, rose hip, and hibiscus-rose hip tea has been shown to interfere with the electrochemiluminescent immunoassay method for measuring serum digoxin levels resulting in false positives. Crossreactivity was not found using the Abbott Digoxin II (MEIA) or Immulite Digoxin assays.42

Adverse Reactions

Research reveals little to no information regarding adverse reactions with the use of hibiscus.2, 28


Data are limited. The median lethal dose of the calyx extract in rats is estimated to be higher than 5 g/kg.2

An experiment in rats using dosages of up to 5 g/kg daily over 12 weeks found a reduction in epididymal sperm count, evidence of histological damage, and disintegration of sperm cells.2 Conversely, a study evaluating the effects of hibiscus 1 g/kg/day on cisplatin-induced reproductive toxicity found a protective effect as measured by sperm motility. The effect was attributed to an antioxidant effect.41

Index Terms

  • Hibiscus rosa-sinensis
  • rose of Sharon


1. Hibiscus sabdariffa L. USDA, NRCS. 2009. The PLANTS Database (, January 2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
2. Ali BH, Al Wabel N, Blunden G. Phytochemical, pharmacological and toxicological aspects of Hibiscus sabdariffa L.: a review. Phytother Res. 2005;19(5):369-375.16106391
3. Leung AY. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics. New York, NY: J Wiley; 1980.
4. Haruna AK. Cathartic activity of soborodo: the aqueous extract of calyx of Hibiscus sabdariffa L. Phytother Res. 1997;11:307-308.
5. Abu-Tarboush HM, Ahmed SA, Al Kahtani HA. Some nutritional and functional properties of karkade (Hibiscus sabdariffa) seed products. Cereal Chem. 1997;74(3):352-355.
6. Haji Faraji M, Haji Tarkhani AH. The effect of sour tea (Hibiscus sabdariffa) on essential hypertension. J Ethnopharmacol. 1999;65(3):231-236.10404421
7. Du CT, Francis FJ. Anthocyanins of roselle (Hibiscus sabdariffa). J Food Sci. 1973;38:810-812.
8. Wilkinson M, Sweeney JG, Lacobucci GA. High performance liquid chromatography of anthocyanins. J Chromatogr. 1977;132:349-351.
9. Sayago-Ayerdi SG, Arranz S, Serrano J, Goni I. Dietary fiber content and associated antioxidant compounds in Roselle flower (Hibiscus sabdariffa L.) beverage. J Agric Food Chem. 2007;55(19):7886-7890.17705439
10. Mohamed R, Fernandez J, Pineda M, Aguilar M. Roselle (Hibiscus sabdariffa) seed oil is a rich source of gamma-tocopherol. J Food Sci. 2007;72(3):S207-S211.17995816
11. Tseng TH, Hsu JD, Lo MH, et al. Inhibitory effect of Hibiscus protocatechuic acid on tumor promotion in mouse skin. Cancer Lett. 1998;126(2):199-207.9585067
12. Tseng TH, Kao TW, Chu CY, Chou FP, Lin WL, Wang CJ. Induction of apoptosis by Hibiscus protocatechuic acid in human leukemia cells via reduction of retinoblastoma (RB) phosphorylation and Bcl-2 expression. Biochem Pharmacol. 2000;60(3):307-315.10856425
13. Chang YC, Huang HP, Hsu JD, Yang SF, Wang CJ. Hibiscus anthocyanins rich extract-induced apoptotic cell death in human promyelocytic leukemia cells. Toxicol Appl Pharmacol. 2005;205(3):201-212.15922006
14. Hou DX, Tong X, Terahara N, Luo D, Fujii M. Delphinidin 3-sambubioside, a Hibiscus anthocyanin, induces apoptosis in human leukemia cells through reactive oxygen species-mediated mitochondrial pathway. Arch Biochem Biophys. 2005;440(1):101-109.16018963
15. Lin HH, Chen JH, Kuo WH, Wang CJ. Chemopreventive properties of Hibiscus sabdariffa L. on human gastric carcinoma cells through apoptosis induction and JNK/p38 MAPK signaling activation. Chem Biol Interact. 2007;165(1):59-75.17145051
16. Lo CW, Huang HP, Lin HM, Chien CT, Wang CJ. Effect of Hibiscus anthocyanins-rich extract induces apoptosis of proliferating smooth muscle cell via activation of P38 MAPK and p53 pathway. Mol Nutr Food Res. 2007;51(12):1452-1460.18030661
17. Olvera-García V, Castaño-Tostado E, Rezendiz-Lopez RI, et al. Hibiscus sabdariffa L. extracts inhibit the mutagenicity in microsuspension assay and the proliferation of HeLa cells. J Food Sci. 2008;73(5):75-81.18577016
18. Hirunpanich V, Utaipat A, Morales NP, et al. Antioxidant effects of aqueous extracts from dried calyx of Hibiscus sabdariffa Linn. (Roselle) in vitro using rat low-density lipoprotein (LDL). Biol Pharm Bull. 2005;28(3):481-484.15744073
19. Hirunpanich V, Utaipat A, Morales NP, et al. Hypocholesterolemic and antioxidant effects of aqueous extracts from the dried calyx of Hibiscus sabdariffa L. in hypercholesterolemic rats. J Ethnopharmacol. 2006;103(2):252-260.16213683
20. Chang YC, Huang KX, Huang AC, Ho YC, Wang CJ. Hibiscus anthocyanins-rich extract inhibited LDL oxidation and oxLDL-mediated macrophages apoptosis. Food Chem Toxicol. 2006;44(7):1015-1023.
21. Carvajal-Zarrabal O, Waliszewski SM, Barradas-Dermitz DM, et al. The consumption of Hibiscus sabdariffa dried calyx ethanolic extract reduced lipid profile in rats. Plant Foods Hum Nutr. 2005;60(4):153-159.16395625
22. Alarcon-Aguilar FJ, Zamilpa A, Perez-Garcia MD, et al. Effect of Hibiscus sabdariffa on obesity in MSG mice. J Ethnopharmacol. 2007;114(1):66-71.17765418
23. Chen CC, Hsu JD, Wang SF, et al. Hibiscus sabdariffa extract inhibits the development of atherosclerosis in cholesterol-fed rabbits. J Agric Food Chem. 2003;51(18):5472-5477.12926900
24. Farombi EO, Ige OO. Hypolipidemic and antioxidant effects of ethanolic extract from dried calyx of Hibiscus sabdariffa in alloxan-induced diabetic rats. Fundam Clin Pharmacol. 2007;21(6):601-609.18034661
25. Odigie IP, Ettarh RR, Adigun SA. Chronic administration of aqueous extract of Hibiscus sabdariffa attenuates hypertension and reverses cardiac hypertrophy in 2K-1C hypertensive rats. J Ethnopharmacol. 2003;86(2-3):181-185.12738084
26. Ajay M, Chai HJ, Mustafa AM, Gilani AH, Mustafa MR. Mechanisms of the anti-hypertensive effect of Hibiscus sabdariffa L. calyces. J Ethnopharmacol. 2007;109(3):388-393.16973321
27. Mojiminiyi FB, Dikko M, Muhammad BY, et al. Antihypertensive effect of an aqueous extract of the calyx of Hibiscus sabdariffa. Fitoterapia. 2007;78(4):292-297.17482378
28. Herrera-Arellano A, Flores-Romero S, Chavez-Soto MA, Tortoriello J. Effectiveness and tolerability of a standardized extract from Hibiscus sabdariffa in patients with mild to moderate hypertension: a controlled and randomized clinical trial. Phytomedicine. 2004;11(5):375-382.15330492
29. Herrera-Arellano A, Miranda-Sánchez J, Avila-Castro P, et al. Clinical effects produced by a standardized herbal medicinal product of Hibiscus sabdariffa on patients with hypertension. A randomized, double-blind, lisinopril-controlled clinical trial. Planta Med. 2007;73(1):6-12.17315307
30. Kirdpon S, Nakorn SN, Kirdpon W. Changes in urinary chemical composition in healthy volunteers after consuming roselle (Hibiscus sabdariffa Linn.) juice. J Med Assoc Thai. 1994;77(6):314-321.7869018
31. Prasongwatana V, Woottisin S, Sriboonlue P, Kukongviriyapan V. Uricosuric effect of Roselle (Hibiscus sabdariffa) in normal and renal-stone former subjects. J Ethnopharmacol. 2008;117(3):491-495.18423919
32. Fouda AM, Daba MH, Dahab GM. Inhibitory effects of aqueous extract of Hibiscus sabdariffa on contractility of the rat bladder and uterus. Can J Physiol Pharmacol. 2007;85(10):1020-1031.18066103
33. Hansawasdi C, Kawabata J, Kasai T. α-Amylase inhibitors from roselle (Hibiscus sabdariffa Linn.) tea. Biosci Biotechnol Biochem. 2000;64(5):1041-1043.10879476
34. Wang CJ, Wang JM, Lin WL, Chu CY, Chou FP, Tseng TH. Protective effect of Hibiscus anthocyanins against tert-butyl hydroperoxide-induced hepatic toxicity in rats. Food Chem Toxicol. 2000;38(5):411-416.10762726
35. Amin A, Hamza AA. Effects of Roselle and Ginger on cisplatin-induced reproductive toxicity in rats. Asian J Androl. 2006;8(5):607-612.16751998
36. Liu JY, Chen CC, Wang WH, Hsu JD, Yang MY, Wang CJ. The protective effects of Hibiscus sabdariffa extract on CCl4-induced liver fibrosis in rats. Food Chem Toxicol. 2006;44(3):336-343.16176854
37. Frank T, Janssen M, Netzel M, et al. Pharmacokinetics of anthocyanidin-3-glycosides following consumption of Hibiscus sabdariffa L. extract. J Clin Pharmacol. 2005;45(2):203-210.15647413
38. Ernst E. Herbal medicinal products during pregnancy: are they safe? BJOG. 2002;109(3):227-235.11950176
39. Mahmoud BM, Ali HM, Homeida MM, Bennett JL. Significant reduction in chloroquine bioavailability following coadministration with Sudanese beverages Aradaib, Karkadi, and Lemon. J Antimicrob Chemother. 1994;33(5):1005-1009.8089046
40. Fakeye TO, Adegoke AO, Omoyeni OC, Famakinde AA. Effects of water extract of Hibiscus sabdariffa, Linn (Malvaceae) 'Roselle' on excretion of a diclofenac formulation. Phytother Res. 2007;21(1):96-98.17094172
41. Amin A, Hamza AA. Hepatoprotective effects of Hibiscus, Rosmarinus and Salvia on azathioprine-induced toxicity in rats. Life Sci. 2005;77(3):266-278.15878355
42. Fresz T, Nagy E, Hilbert A, Tomcsanyi J. The role of flavonoids in false positive digoxin assays caused by the consumption of hibiscus flower and rose hip tea. Int J Cardiol. 2014;171(2):273-274.24365615
43. Serban C, Sahebkar A, Ursoniu S, Andrica F, Banach M. Effect of sour tea (Hibiscus sabdariffa L.) on arterial hypertension: asystematic review and meta-analysis of randomized controlled trials. J Hypertens. 2015;33(6):1119-1127.25875025


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