Banaba leaf extract is derived from the banaba tree (Lagerstroemia speciosa), which grows throughout Asia. The mature leaves are washed and extracted, and the extract is then filtered, concentrated, and spray-dried. It is standardized to contain 1% corosolic acid, usually most concentrated in mature leaves.Other active components include gallic acid and ellagic acid. Banaba has been traditionally valued in the Philippines as a medicinal herb.
Corosolic acid in Banaba leaf extract may contain antioxidant properties and lower lipid levels in the blood (antihyperlipidemic).Corosolic acid may alsoand thus decrease the risk of type 2 diabetes. It has been suggested in a preclinical study that gallic and ellagic acid may contain anti-HIV activity.
Individuals taking diabetic medication should consult a professional before consuming banaba leaf extracts. Corosolic acid in Banaba leaf extract has been seen to lower blood sugar levels within 60 minutes of administration, which might cause glucose levels to be too low if taken with diabetic medication.