Banaba has been used in the Philippines for blood sugar control. See diabetes for information on supplements and herbs that have an influence on blood sugar, including lipoic acid. One of the active ingredients in banaba leaf is corosolic acid and there has been some research done with banaba in Japan. I have not come across any human studies with banaba, but there has been at least one human study with corosolic acid (an extract found in banaba) that showed improvement in blood sugar control in type II diabetics. At this point it is difficult to predict the blood sugar response to a banaba supplement and it is difficult to know what dosage works best and how often to take a banaba supplement or how it interacts with other supplements used for blood sugar control. We also don't know how a banaba supplement would interact with oral medicines used in diabetes and how it would interact with insulin. If you are a type II diabetic, discuss with your doctor regarding the use of a banaba supplement to see if this herbal supplement is appropriate for your particular condition. This banaba will be updated on a regular basis when new banaba research is published. 
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Banaba Leaf Extract, 250 mg
12:1 Extract 60 Capsules Club Natural
Other herbs and nutrients involved in blood sugar control include cinnamon, fenugreek, chromium, and lipoic acid.

Banaba leaf is naturally extracted using only the finest quality banaba leaves. Banaba Leaf potent extract provides active levels of corosolic acid, without isolating, fractionizing or using toxic solvents, harsh chemicals or gases. Banaba leaf extract may stimulate glucose transport into cells.

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Subscribe to a FREE Supplement Research Update newsletter. Twice a month you will receive an email with several studies on various supplements and natural medicine topics, including banaba and blood sugar control, and their practical interpretation by Ray Sahelian, M.D.

Banaba Leaf Supplement Facts:
Banaba leaf extract 12:1
(Lagerstoemia speciosa) 250 mg *
    (Equivalent to 3,000 mg whole leaf) 1.5 % Corosolic Acid = 3.75 mg
* Banaba leaf daily value not established

Suggested Use: 1 or 2 Banaba leaf extract capsules daily or as directed by a qualified healthcare professional. Since each patient with diabetes is unique, it is difficult to predict the appropriate banaba dosage.

Benefits of Diet Rx with banaba
All natural appetite suppressant, decreases appetite so you eat less
Helps you maintain healthy blood sugar levels
Helps you maintain healthy cholesterol and lipid levels
Provides a variety of antioxidant from two dozen herbs and nutrients
Provides healthy fiber
Improves energy
Balances mood
Improves mental concentration and focus
Improves will power and choice of food selection

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Banaba Leaf Research Update
Effects of dietary mulberry, Korean red ginseng, and banaba on glucose homeostasis in relation to PPAR-alpha, PPAR-gamma, and LPL mRNA expressions.
Life Sci. 2005 Nov 12;77(26):3344-54. Department of Food and Nutrition, College of Human Ecology, Sookmyung Women's University, Seoul, Korea.
Mulberry leaf water extract, Korean red ginseng, banaba leaf water extract, and the combination of these herbs fed to mice at the level of 0.5% of the diet significantly increased insulin sensitivity and improved hyperglycemia possibly through regulating PPAR-mediated lipid metabolism.

Effects of malted barley extract and banaba extract on blood glucose levels in genetically diabetic mice.
J Med Food. 2004 Winter;7(4):487-90.
This study investigated the therapeutic effects of a malted barley extract (MBE) and of banaba extract on blood glucose, insulin, and other biochemical parameters in genetically diabetic mice. The mice were divided into three groups-control, MBE, and banaba-according to supplementation. Both MBE and banaba extracts were orally administered to the animals for 12 weeks at doses of 62 mg/kg of body weight and 0.8 mg/kg of body weight, respectively. The body and organ (liver and kidney) weights were not different among groups. Fasting blood glucose was significantly lower in the MBE group compared with the control. Hemoglobin A1c content was significantly lower in the MBE group compared with either the control or banaba group. There was no significant difference in the serum insulin level among groups. The glucose-6-phosphatase activity in kidney was significantly lower in both the MBE and banaba groups compared with the control group, but there was no significant difference between the MBE and banaba groups. Therefore, the results of this study demonstrate that MBE alleviates many of the symptoms of diabetes in genetically obese mice and may offer promise as a therapeutic supplement for the normalization of blood glucose levels in humans with hyperglycemia and have beneficial effects in patients with non-insulin-dependent diabetes mellitus.

Antidiabetic activity of a standardized extract (Glucosol) from Lagerstroemia speciosa leaves - banaba - in Type II diabetics. A dose-dependence study.
J Ethnopharmacol. 2003 Jul;87(1):115-7. Judy WV, Hari SP, Stogsdill WW, Judy JS, Naguib YM, Passwater R.
SIBR, Inc., 4112 20th Street West, Bradenton, FL
The antidiabetic activity of an extract from the leaves of Lagerstroemia speciosa standardized to 1% corosolic acid (Glucosol) has been demonstrated in a randomized clinical trial involving Type II diabetics. Subjects received a daily oral dose of Glucosol and blood glucose levels were measured. Glucosol at daily dosages of 32 and 48mg for 2 weeks showed a significant reduction in the blood glucose levels.

[Isolation and quantitative analysis of the alpha-amylase inhibitor in Lagerstroemia speciosa (L.) Pers. (Banaba)]
Yakugaku Zasshi. 2003 Jul;123(7):599-605.
Banaba has been used as a folk medicine for diabetes in the Philippines. Using bioassay-guided separation, valoneaic acid dilactone (1) was isolated from the leaves as a potent alpha-amylase inhibitor. A simple and efficient method for the quantitative determination of valoneaic acid and its derivatives in Banaba extract was established. Valoneaic acid exists as the structural part of the polyphenols, which like flosin A, reginin A, and lagerstroemin, are characteristic constituents of Banaba. These derivatives were hydrolyzed to valoneaic acid by HCl and extracted with 2-butanone. This extract was subjected to HPLC analysis, and the contents of valoneaic acid determined as the whole valoneaic acid contents. Using this method, the whole valoneaic acid contents were measured in eight Banaba leaf decoctions. The alpha-amylase-inhibiting activities of the decoctions were dependent on the whole valoneaic acid contents. In addition, a strong linear correlation was observed between the whole valoneaic acid contents and total polyphenol contents. This analytical procedure is applicable to the chemical evaluation of Banaba.

An extract of Lagerstroemia speciosa L. has insulin-like glucose uptake-stimulatory and adipocyte differentiation-inhibitory activities in 3T3-L1 cells.
J Nutr. 2001 Sep;131(9):2242-7.
The effects of extracts isolated from Lagerstroemia speciosa L. ( banaba ) on glucose transport and adipocyte differentiation in 3T3-L1 cells were studied. Glucose uptake-inducing activity of banaba extract was investigated in differentiated adipocytes using a radioactive assay, and the ability of banaba extract to induce differentiation in preadipocytes was examined by Northern and Western blot analyses. The unique combination of a glucose uptake stimulatory activity, the absence of adipocyte differentiation activity and effective inhibition of adipocyte differentiation induced by IS-IBMX-DEX in 3T3-L1 cells suggest that banaba extract may be useful for prevention and treatment of hyperglycemia and obesity in type II diabetics.

Antiobesity activity of extracts from Lagerstroemia speciosa L. leaves on female KK-Ay mice.
J Nutr Sci Vitaminol (Tokyo). 1999 Dec;45(6):791-5.
Banaba in the Tagalog name, Lagerstroemia speciosa L., has been used as a folk medicine for a long time among diabetics in the Philippines. Extracts from banaba leaves have been reported to reduce diabetic symptoms in genetically diabetic mice. In the present study, female mice of the same strain showing remarkable body weight gain were used to examine the antiobesity effect of dietary banaba extract. Five-week-old female KK-Ay mice were fed a control diet or test diet containing 5% of a hot-water extract from banaba leaves instead of cellulose for 12 wk. Neither group showed any changes in diet intake during the experimental period. Body weight gain and parametrial adipose tissue weight were lowered significantly in the banaba diet group. Blood glucose levels were not suppressed in the banaba diet group, but hemoglobin A1C was found to be suppressed at the end of the experiment. No effects on the serum lipids were observed, but the mice fed banaba extract showed a significant decrease, to 65% of the control level in total hepatic lipid contents. This decrease was due to a reduction in the accumulation of triglyceride. These results suggest that banaba had a beneficial effect on obese female KK-Ay mice.
banaba leaf extract banaba herbs.

Hypoglycemic effect of extracts from Lagerstroemia speciosa L. banaba leaves in genetically diabetic KK-AY mice.
Biosci Biotechnol Biochem. 1996 Feb;60(2):204-8. banaba tea banaba extract
The hypoglycemic effects of Lagerstroemia speciosa L., known by the Tagalog name of banaba in the Phillipines, were studied using hereditary diabetic mice. The mice were fed a test diet containing 5% of the hot-water extract from banaba leaves for a feeding period of 5 weeks. It is suggested that extracts obtained from banaba leaves have beneficial effects on control of the level of plasma glucose in non-insulin dependent diabetes mellitus.

Tannic acid in banaba herb
Tannic acid stimulates glucose transport and inhibits adipocyte differentiation in 3T3-L1 cells.
J Nutr. 2005 Feb;135(2):165-71.
Liu X, Kim JK, Li Y, Li J, Liu F, Chen X. Department of Biochemistry, Edison Biotechnology Institute, College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA.
Adipogenesis, the differentiation and proliferation of adipocytes, is a major mechanism leading to weight gain and obesity. Previously, we reported that an extract from Lagerstroemia speciosa L. ( banaba ) possessed activities that both stimulated glucose transport and inhibited adipocyte differentiation in 3T3-L1 cells. We showed that the banaba extract with tannin removed was devoid of the 2 activities, and tannic acid, a major component of tannins, had the same 2 activities as banaba extract. We also demonstrated that tannic acid inhibited the expression of key genes for adipogenesis. These results suggest that tannic acid may be useful for the prevention and treatment of type 2 diabetes and its associated obesity. Tannic acid may have the potential to become the lead compound in the development of new types of antidiabetic pharmaceuticals that are able to reduce blood glucose levels without increasing adiposity.

Banaba leaf emails
Q. Is banaba for diabetes? Does banaba have side effects?
   A. Historically banaba for diabetes has been tried in other cultures, but the use of banaba for diabetes in the US is still very new and we don't really know the right dosage or how often to take banaba and also how it interacts with insulin or hypoglycemic medicines. There is no proof yet that taking a banaba supplement will help those who have diabetes, although rodent studies thus far look promising. We also don't know whether long term use of a banaba supplement will lead to side effects. I am not aware of any studies combining banaba with metformin or other medicines used in diabetes.

Q. How does banaba tea compare to banaba capsule?
   A. I really don't know how potent banaba tea is compared to a banaba supplement.

Q. I see a product called GlucoTrim which states "Lagerstroemia speciosa extract standardized to 1% corosolic acid, 24 mg." Does this mean this banaba product has 24 mg of corosolic acid, or does it have 1% corosolic acid out of the 24 mg of banaba herb present?
   A. We are trying to figure this out ourselves. We're not sure if GlucoTrim is 24 mg of corosolic acid or whether it is just a banaba extract with 1% corosolic acid.

Q. What's the right dosage of banaba to treat diabetes or blood sugar problems?
   A. Since so little research has been done with banaba, corosolic acid, and diabetes, that it is very difficult to say at this time what the ideal dosages of banaba or corosolic should be, or how often to take these supplements, and how effective they are in the long run. We also don't have much knowledge on potential banaba side effects, if any. Another point to keep in mind is that we are not sure if there are other compounds in banaba besides corosolic acid that could help with blood sugar control. Sometimes it is tempting to focus on one substance in an herb, but there could be synergism with other substances found within the plant.

Q. Can you tell me of any studies done with horses using banaba? is it poisonous for horses? where could I look for information using this for a horse with insulin resistance?
   A. We don't deal with horses so we don't know whether banaba is helpful to animals. A quick search on Medline did not reveal any studies with the keywords banaba horse or banaba equine.

Q. I want to know can banaba herb be used as a hepatoprotective herb ?
   A. We have not seen any human studies evaluating the effect of banaba herb supplementation on liver enzymes.

Q. My kidneys are about half as functional due to diabetes. Would banaba product help me without further damage to kidneys. i do take Byetta plus Novalog plus Lantus. Would it conflict with this?
   A. Banaba supplement has not been tested in combination with Byetta, Novalog, Lantus, or other medications used for diabetes. We are not aware of any kidney damage that would occur from the use of a banaba supplement, however very little human research is available with this supplement.

This banaba page was last updated March 2008.