Banaba leaf

What is banaba?

Banaba (Lagerstroemia speciosa) is a flowering tree native to Southeast Asia, India and the Philippines, where tea made from its leaves has long been used as a folk remedy for high blood sugar. The leaves contain corosolic acid, a triterpene, along with ellagitannins. Most banaba supplements are extracts standardized to a small percentage of corosolic acid.

What the research says

A review of the efficacy and safety of banaba and corosolic acid published in Phytotherapy Research summarizes research going back to 1940. Studies have used animal models, laboratory systems and a limited number of human subjects. The review reports that pure corosolic acid has been shown to lower blood sugar within 60 minutes in people, and it describes several proposed mechanisms, including increased glucose uptake into cells, reduced breakdown of starches and sucrose, and decreased glucose production by the liver. The authors reported that no adverse effects had been observed in animal studies or in controlled human trials.

It is important to read this in context. The review is a narrative summary rather than a meta-analysis, many of the findings come from animal or lab studies, and the human trials have been small and short. We found no evidence that banaba supports balance, the main claim for Claritox Pro, and its mechanism points squarely at blood sugar.

We rate the evidence as preliminary.

How it’s used in supplements

Banaba appears in capsules and in many multi-ingredient blood sugar products, usually as an extract standardized to about 1 percent corosolic acid. There is no well-established dose, and products vary in how much corosolic acid they deliver.

Because banaba may lower blood sugar, combining it with insulin, sulfonylureas or other glucose-lowering drugs, or with other glucose-lowering supplements such as berberine and chromium (both of which are also in Claritox Pro), could increase the risk of low blood sugar. Symptoms of low blood sugar include shakiness, sweating, confusion and, notably, dizziness. People with diabetes should talk to their doctor before using banaba and monitor their glucose. There is not enough information on its safety during pregnancy or breastfeeding, so it is best avoided then.

In Claritox Pro, banaba is listed without an amount or standardization.

The combination matters here. Claritox Pro is marketed to people who worry about feeling dizzy, yet it pairs three ingredients that may lower blood sugar. For someone on diabetes medication, that pairing could in theory make lightheadedness more likely rather than less, which is one more reason to involve a doctor before trying it.