Skip to main content


Scientific Name(s): Lagerstroemia speciosa (L.) Pers.
Common Name(s): Banaba, Crepe myrtle, Pride of India, Queen's crepe myrtle, Queen's flower

Medically reviewed by Last updated on May 23, 2022.

Clinical Overview


Banaba leaf preparations have been used in Philippine folk medicine for treatment of diabetes. Certain constituents (eg, corosolic acid) possess hypoglycemic activity. Several animal studies of banaba have demonstrated hypoglycemic effects, but more clinical studies are needed.


Limited clinical trial data exist to provide dosing recommendations. Doses of 32 mg or 48 mg of the standardized extract from L. speciosa leaves (Glucosol) (standardized to 0.32 and 0.48 mg of corosolic acid, respectively) were given daily for 10 days in one small study of patients with type 2 diabetes.


None well documented.


Avoid use. Information regarding safety and efficacy in pregnancy and lactation is lacking.


A case report exists of nephrotoxicity in a diabetic patient, potentially related to an interaction with diclofenac. Anticoagulant/Antiplatelet drugs: Antithrombin activity has been reported for the related species Lagerstroemia indica. Xanthine oxidase: Aqueous extracts from the plant leaves may have an additive effect in the treatment of hyperuricemia.

Adverse Reactions

None well documented.


No toxicity has been reported, even in high doses.

Scientific Family

  • Lythraceae


Banaba is a deciduous, tropical, flowering tree that grows in India, Southeast Asia, and the Philippines. It typically grows 5 to 10 m in height, and sometimes up to 20 m. The smooth, large, spatulate, oblong to elliptic-ovate leaves measure 4 to 8 cm in width and 12 to 25 cm in length. The flowers are pink to purple when in bloom, and give way to oval, nut-like fruits; the leaves turn orange-red in the fall. The bark of the tree is smooth, grey to cream colored, and peels off in flakes.1, 2, 3


Banaba has been used as a folk medicine to treat diabetes in various parts of the world, especially in the Philippines and Southeast Asia. Folkloric use of banaba leaf decoctions for diuretic and purgative purposes and of root parts for stomach ailments has also been recorded. The first published research study evaluating the insulin-like activity of an aqueous extract of dried leaves given to rabbits was reported in 1940; since then, studies evaluating banaba for treatment of diabetes have been conducted in animal models, humans, and in vitro laboratory settings.3, 4


Banaba leaves contain ellagic acid derivatives.5 Reports have confirmed the presence of ellagitannins, lagerstroemin, flosin B, and reginin A, all possible glucose transport enhancers.6 Lagertannins, beta-sitosterol, stigmasterol, campesterol, and some olefins also have been found in banaba leaves and extracts.6, 7, 8, 9 Lageracetal (1,1-Dibutoxybutane), 1-pentanol, ellagic acid, and corosolic acid (a triterpene) have been isolated from the leaves.10, 11 One study reports that 16 amino acids, pyrogallol tannins, and lipids are also present in banaba leaf.12 Nonacosane, hentriacontane, tritriacontane, olefins, and esters of palmitic, daturic, stearic, arachinic, and behenic acids were identified from the neutral fraction of hot ethanol extracts of banaba leaves.13

Banaba bark contains similar constituents to its leaves. One report found ellagic acids, beta-sitosterols, and colosolic acids in bark extracts.14

L. speciosa seeds contain caprylic, lauric, myristic, palmitic, steric, arachidic, behenic, lignoceric, oleic, and linoleic acids in the oil15; 9-keotoctadec-cis-11-enoic acid has been isolated from the seed oil as well.16 Chemical investigation of amino acid components in banaba seed oil has been performed.17 The components nonanedioic acid, 12-acetyloxy-9-octadecenoic acid, and 16-methyl-heptadecandic acids, present in the seed extracts, have been identified as having antibacterial activity.18

L. speciosa and related species contain ellagic acid, campesterol, stigmasterol, and beta-sitosterol in their stem parts.19

Uses and Pharmacology

Animal and clinical studies have demonstrated hypoglycemic effects of both the aqueous and methanol extracts; most studies have focused on corosolic acid. The water-soluble tannin fractions (ie, ellagitannins) may provide antioxidant, anti-inflammatory, insulin-like, and glucose regulatory activities.4


Animal data

Anti-inflammatory activity in mice has been reported.8 Insight into the anti-inflammatory mechanism of action of banaba may be gained from results of an in vitro experiment in a cardiomyocyte cell line in which an aqueous extract blocked activation of nuclear factor-kappaB by tumor necrosis factor in a time-dependent manner.4 Corosolic acid demonstrated effective anti-inflammatory activity against arachidonic acid and 12-O-tetradecanoylphorbol-13 acetate, as assessed in vivo using a mouse ear assay.4, 20

Clinical data

Research reveals no clinical data regarding the use of L. speciosa as an anti-inflammatory agent.


Animal data

In various reports, the constituent corosolic acid was shown to be a glucose transport activator, suggesting antidiabetic activity. Further investigation has revealed valoneaic acid dilactone as the amylase inhibitor. The ellagitannins lagerstroemin, flosin B, and reginin A increased glucose uptake by rat adipocytes.6, 11, 21

Another report observed inhibitory effects of banaba on postprandial hyperglycemia via inhibition of alpha-amylase and alpha-glucosidases.22, 23

Banaba extracts have been examined in several rodent studies, with reported beneficial effects on blood glucose levels and obesity.24, 25, 26, 27

Clinical data

Reviews of medical literature on the effects of banaba in diabetes have identified few quality clinical trials and a number of open-label or small clinical studies.2, 4, 28

One small clinical trial (N=10) involving patients with type 2 diabetes reported that banaba extract standardized to 1% corosolic acid and administered for 10 days reduced blood glucose levels.29 In a small, open-label study (N=15), 100 mg of a water-soluble banaba extract administered for 1 year produced a significant decrease (16.6%) in fasting blood glucose in individuals with blood glucose levels greater than 110 mg/dL. Improvements in both glucose tolerance and glycated albumin were observed after 6 months, as well as after 1 year of treatment.4

Data from other unpublished studies and reports are generally supportive of a role for banaba in treating diabetes; however, additional quality clinical trials are required before definitive statements or recommendations can be made.2, 4 Other studies have evaluated banaba in combination with other natural products.4, 28 For example, a combination of cinnamon and banaba improved insulin resistance in patients with impaired glucose tolerance.30 Clinical trials evaluating antiobesity effects are lacking.

Other uses

Banaba aqueous extract was shown to have potent radical scavenging activity, in a concentration-dependent manner, on 1,1-diphenyl-2-picrylhydrazyl radical and superoxide radicals generated by a hypoxanthine-xanthine oxidase system. Additionally, lipid peroxidation was inhibited in a rat liver homogenate system.31, 32 Further antioxidant activity has been reported.4, 33, 34, 35

Other reported activities of banaba preparations include antibacterial, antifungal, and antiviral.4, 18, 35, 36, 37, 38, 39 Protection of HIV-infected cells by ellagic acid constituents, possibly via inhibition of reverse transcriptase and HIV protease, has been reported.14, 40

Various in vitro studies report effects of corosolic acid on a variety of human tumor cells.4, 41 In vitro, valoneic acid, a constituent of banaba, has demonstrated xanthine oxidase–inhibiting activity.2



Limited clinical trial data exist to provide dosing recommendations. Doses of 32 mg or 48 mg of the standardized extract from L. speciosa leaves (Glucosol) (standardized to 0.32 and 0.48 mg of corosolic acid, respectively) were given daily for 10 days in one small study.29

Pregnancy / Lactation

Avoid use. Information regarding safety and efficacy in pregnancy and lactation is lacking.


A case report exists of nephrotoxicity in a diabetic patient, potentially related to an interaction with diclofenac.42

Hypoglycemic drugs, insulin: Banaba has been shown to produce insulin-like actions and may have additive effects if taken concomitantly with diabetic drugs.2 Anticoagulant/Antiplatelet drugs: Antithrombin activity has been reported for the related species L. indica.2

Xanthine oxidase: Aqueous extracts from the plant leaves may have an additive effect in the treatment of hyperuricemia.2 An extract of banaba has been shown to inhibit the sulfation of dopamine and ritodrine, with a 50% inhibition at concentrations of 16 and 7.5 mcg/mL, respectively. The bioavailability of drugs detoxified by intestinal sulfotransferase 1A3 may be increased by banaba.4

Adverse Reactions

No adverse effects have been reported; clinical trials are lacking to provide information regarding adverse effects.4, 43 Use caution in patients with diabetes due to the potential of banaba to lower blood sugar.2


No toxicity has been reported, even in high doses.44 In one report, large oral doses did not produce toxic effects or convulsions.45


1. Lagerstroemia speciosa (L.) Pers. [pride of India]. USDA, NRCS. 2016. The PLANTS Database (, December 2016). National Plant Data Team, Greensboro, NC 27401-4901 USA. Accessed December 2016.
2. Ulbricht C, Dam C, Milkin T, Seamon E, Weissner W, Woods J. Banaba (Lagerstroemia speciosa L.): an evidence-based systematic review by the Natural Standard research collaboration. J Herb Pharmacother. 2007;7(1):99-113.
3. Banaba Lagerstroemia speciosa (L.) Pers. Philippine Medicinal Plants website. Updated March 2017. Accessed April 27, 2017.915708
4. Stohs SJ, Miller H, Kaats GR. A review of the efficacy and safety of banaba (Lagerstroemia speciosa L.) and corosolic acid. Phytother Res. 2012;26(3):317-324.22095937
5. Takahashi M, Ueda J, Sasaki JI. The components of the plants of Lagerstroemia genus. IV. On the presence of the ellagic acid derivatives from the leaves of Lagerstroemia subcostata Koehne, and L. speciosa (L.) Pers. and the synthesis of 3,4-di-O-methylellagic acid [in Japanese]. Yakugaku Zasshi. 1977;97(8):880-882.915708
6. Hayashi T, Maruyama H, Kasai R, et al. Ellagitannins from Lagerstroemia speciosa as activators of glucose transport in fat cells. Planta Med. 2002;68(2):173-175.11859474
7. Takahashi M, Osawa K, Ueda J, Yamamoto F, Tsai CT. The components of the plants of Lagerstroemia genus. ΙΙΙ. On the structure of the new tannin "lagertannin" from the leaves of Lagerstroemia speciosa (L.) Pers. [in Japanese]. Yakugaku Zasshi. 1976;96(8):984-987.1035947
8. Garcia LL, Fojas FR, Castro IR, Venzon EL, Sison FM, Capal TV. Pharmaceutico-chemical and pharmacological studies on a crude drug from Lagerstroemia speciosa (L.) Pers. Philipp J Sci. 1987;116:361-375.4738533
9. Tanaka T, Tong HH, Xu Y, Ishimaru K, Nonaka G, Nishioka I. Tannins and related compounds. CXVII. Isolation and characterization of three new ellagitannins, lagerstannins A, B, and C, having a gluconic acid core, from Lagerstroemia speciosa (L.) Pers. Chem Pharm Bull. 1992;40:2975-2980.
10. Takahashi M, Osawa K, Sato T, Ueda J, Fujita Y. The chemical structure of the new component "lageracetal" from the leaves of Lagerstroemia speciosa (L.) Pers. [in Japanese]. Yakugaku Zasshi. 1973;93(7):861-863.4738533
11. Egawa K. Lagerstroemia speciosa (Banaba). Ota M, Shokuhin KS II, eds. Tokyo, Japan: Shi Emu Shi; 2001:237-241.
12. Manalo J, DeVera FV, Bonifacio TS, Unalivia FD, Arida VP. Phytochemical investigation of Lagerstroemia speciosa leaves (banaba) I. Pers. Philipp J Sci. 1993;122:15-31.
13. Takahashi M, Osawa K, Ueda J, Yamazaki J. The components of the plants of Lagerstroemia speciosa (L.) Pers [in Japanese]. Annual Report of the Tohoku College of Pharmacy. 1979;26:65-68.
14. Faruk MJ, Nahar N, Aziz MA, Mosihuzzaman M, Rashid MA. Two new ellagic acids from Lagerstroemia speciosa Linn. plant. J Bangladesh Chem Soc. 2002;15:73-78.
15. Badami R, Kudari SM. Component acids of Lagerstroemia speciosa seed oil. Indian J Appl Chem. 1970;33:213-215.
16. Jehan C, Daulatabad D, Mirajkar AM. A keto fatty acid from Lagerstroemia speciosa seed oil. Phytochemistry. 1990;29:2323-2324.
17. Laskarz S, Sinhababu A, Thakur S, Basak B. Extraction and chemical investigation of Lagerstroemia speciosa seed proteins. Am Lab. 1998;30:22,24.
18. Sinhababu A, Das S, Laskar S, Thakur S, Sen SK. Characterization and identification of antibacterial components in extracts of seeds from Lagerstroemia speciosa. Adv Food Sci. 1999;21:19-22.
19. Takahashi M, Sato T, Ueda J. The components of the plants of Lagerstroemia genus. VII. The components in the stems. Annual Report of the Tohoku College of Pharmacy. 1981;28:85-87.
20. Kim SJ, Cha JY, Kang HS, et al. Corosolic acid ameliorates acute inflammation through inhibition of IRAK-1 phosphorylation in macrophages. BMB Rep. 2016;49(5):276-281.26615974
21. Murakami C, Myoga K, Kasai R, et al. Screening of plant constituents for effect on glucose transport activity in Ehrlich ascites tumour cells. Chem Pharm Bull (Tokyo). 1993;41(12):2129-2131.8118906
22. Suzuki Y, Hayashi K, Sakane I, Kakuda T. Effect and mode of action of banaba (Lagerstroemia speciosa L.) leaf extracts on postprandial blood glucose in rats [in Japanese]. Nihon Eiyo Shokuryo Gakkai Shi. 2001;54:131-137.
23. Trinh BT, Staerk D, Jäger AK. Screening for potential α-glucosidase and α-amylase inhibitory constituents from selected Vietnamese plants used to treat type 2 diabetes. J Ethnopharmacol. 2016;186:189-195.
24. Kakuda T, Sakane I, Takihara T, Ozaki Y, Takeuchi H, Kuroyanagi M. Hypoglycemic effect of extracts from Lagerstroemia speciosa L. leaves in genetically diabetic KK-AY mice. Biosci Biotechnol Biochem. 1996;60(2):204-208.9063966
25. Hamamoto S, Kogami H, Kohata K, Moriwaki M, Kanada H, Matsuyama F. Glucosol effect on blood glucose in rats [in Japanese]. Yakuri To Chiryo. 1999;27:1075-1077.
26. Suzuki Y, Unno T, Ushitani M, Hayashi K, Kakuda T. Antiobesity activity of extracts from Lagerstroemia speciosa L. leaves on female KK-Ay mice. J Nutr Sci Vitaminol (Tokyo). 1999;45(6):791-795.10737232
27. Mishra Y, Khan MS, Zafar R, Agarwal SS. Hypoglycaemic activity of leaves of Lagerstroemia speciosa (L.) Pers. Indian J Pharmacol. 1990;22:174-176.
28. Miura T, Takagi S, Ishida T. Management of diabetes and its complications with banaba (Lagerstroemia speciosa L.) and corosolic acid. Evid Based Complement Alternat Med. 2012;2012:871495.23082086
29. Judy WV, Hari SP, Stogsdill WW, Judy JS, Naguib YM, Passwater R. Antidiabetic activity of a standardized extract (Glucosol) from Lagerstroemia speciosa leaves in type II diabetics. A dose-dependence study. J Ethnopharmacol. 2003;87(1):115-117.12787964
30. Manaf A, Tjandrawinata RR, Malinda D. Insulin sensitizer in prediabetes: a clinical study with DLBS3233, a combined bioactive fraction of Cinnamomum burmanii and Lagerstroemia speciosa. Drug Des Devel Ther. 2016;10:1279-1289.27099473
31. Unno T, Sakane I, Masumizu T, Kohno M, Kakuda T. Antioxidative activity of water extracts of Lagerstroemia speciosa leaves. Biosci Biotechnol Biochem. 1997;61(10):1772-1774.27393177
32. Unno T, Sakane I, Kakuda T. Inhibition of xanthine oxidase by an aqueous extract of banaba leaves (Lagerstroemia speciosa) [in Japanese]. Nippon Shokuhin Kagaku Kogaku Kaishi. 2000;47:740-743.
33. Sahu BD, Kuncha M, Rachamalla SS, Sistla R. Lagerstroemia speciosa L. attenuates apoptosis in isoproterenol-induced cardiotoxic mice by inhibiting oxidative stress: possible role of Nrf2/HO-1. Cardiovasc Toxicol. 2015;15(1):10-22.24853613
34. Guo X, Cui R, Zhao J, Mo R, Peng L, Yan M. Corosolic acid protects hepatocytes against ethanol-induced damage by modulating mitogen-activated protein kinases and activating autophagy. Eur J Pharmacol. 2016;791:578-588.27663281
35. Sinhababu A, Basak B, Laskar S, Chakrabarty D, Sen SK. Effect of different fractions of petroleum ether (60-80 degrees) extract of the seeds of Lagerstroemia speciosa (Linn. ex Murray) Pers. on some microorganisms. Hindustan Antibiot Bull. 1994;36(1-2):39-45.7737896
36. Singh BN, Singh HB, Singh A, Singh BR, Mishra A, Nautiyal CS. Lagerstroemia speciosa fruit extract modulates quorum sensing-controlled virulence factor production and biofilm formation in Pseudomonas aeruginosa. Microbiology. 2012;158(pt 2):529-538.22117007
37. Song JH, Park KS, Kwon DH, Choi HJ. Anti-human rhinovirus 2 activity and mode of action of quercetin-7-glucoside from Lagerstroemia speciosa. J Med Food. 2013;16(4):274-279.23566054
38. Song JL, Zhao X, Wang Q, Zhang T. Protective effects of Lagerstroemia speciosa on 3-morpholinosydnonimine (SIN-1)-induced oxidative stress in HIT-T15 pancreatic β cells. Mol Med Rep. 2013;7(5):1607-1612.23545843
39. Park SW, Kwon MJ, Yoo JY, Choi HJ, Ahn YJ. Antiviral activity and possible mode of action of ellagic acid identified in Lagerstroemia speciosa leaves toward human rhinoviruses. BMC Complement Altern Med. 2014;14:171.24885569
40. Nutan, Modi M, Goel T, et al. Ellagic acid & gallic acid from Lagerstroemia speciosa L. inhibit HIV-1 infection through inhibition of HIV-1 protease & reverse transcriptase activity. Indian J Med Res. 2013;137(3):540-548.23640562
41. Sung B, Kang YJ, Kim DH, et al. Corosolic acid induces apoptotic cell death in HCT116 human colon cancer cells through a caspase-dependent pathway. Int J Mol Med. 2014;33(4):943-949.24481288
42. Zheng JQ, Zheng CM, Lu KC. Corosolic acid-induced acute kidney injury and lactic acidosis in a patient with impaired kidney function. Am J Kidney Dis. 2010;56(2):419-420.
43. Posadzki P, Watson LK, Ernst E. Adverse effects of herbal medicines: an overview of systematic reviews. Clin Med (Lond). 2013;13(1):7-12.23472485
44. Vohora SB, Khan MS. Pharmacological studies on Lagerstroemia speciosa. J Res Ayur Sidba. 1982;3:23-27.
45. Garcia F. Distribution and deterioration of the insulin-like principle in Lagerstroemia speciosa (banaba). Acta Med Philipp. 1941;3:99-104.


This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.

This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.

More about banaba

Related treatment guides

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.