Banaba is a variety of crepe myrtle that grows in the Philippines, India, Malaysia and Australia. A tea made from the leaves is used to treat diabetes.

Active ingredients include corsolic acid and tannins, including lagerstroemin. These ingredients are thought to stimulate glucose uptake and have insulin-like activity. The latter activity is thought to be secondary to activation of the insulin receptor tyrosine kinase or the inhibition of tyrosine phosphatase.

Banaba has been used for diabetes and weight loss, although information regarding long-term human use is not available. No adverse effects have been reported with its use.

Drug Interactions

Banaba may cause blood glucose to be excessively lowered when combined with drugs that can cause hypoglycemia, such as sulfonylureas (glyburide or glipizide), or with complementary and alternative medicines (CAM) that have hypoglycemic activity (Gymnema sylvestre, American ginseng, and the like). Doses of these medications or CAM therapies may have to be adjusted to prevent excessive lowering of blood glucose.

What is banaba, and can it help my diabetes?

Banaba is a leaf extract from a crepe myrtle species found in the Philippines and Southeast Asia. This product may help promote glucose uptake and produce insulin-like effects. It has been studied in rodents, but a small study in patients with type 2 diabetes found that a soft-gel formulation of the extract, called Glucosol (now called GlucoTrim), lowered glucose.

There are no serious side effects associated with the use of banaba, but hypoglycemia may occur, and the patient’s dose of diabetes medications may have to be lowered. There is limited information regarding the use of this product, so it is not recommended at this time.

A 15-day randomized control trial on banaba was done in 10 patients with type 2 diabetes and fasting glucose levels between 140 and 250 mg/dl. The results of the trial were published in a 2003 issue of the Journal of Pharmacological Sciences (93:69-73).

Diabetes medications were stopped 45 days before the study. Three different doses of banaba—16 mg, 32 mg, or 48 mg—in either a soft-gel or hard-gel formulation were used.

Five subjects in each group received the three different doses for 15 days, with a 10-day washout between doses. Basal glucose was determined by a fasting blood sample seven days before starting banaba.

During the study, three samples were taken, and an average of the three readings was compared to the basal value. The 32- and 48-mg soft-gel formulations showed 11 percent and 30 percent decreases, respectively, from basal values after 15 days of treatment. Only the 48 mg hard-gel formulation showed a significant decrease of 20 percent, but it was still lower than the soft-gel formulation.

Some online sources for gel and tea formulations of banaba are

www.tropicaltraditions.com/banaba.htm

www.bodybuilding.com/store/banaba.html

www.FindSupplements.com

www.HerbsMD.com

www.herbalnutricon.com