corosolic acid

PhytochemicalTriterpene

What is it

Corosolic acid is a pentacyclic triterpenoid most abundant in banaba leaf (Lagerstroemia speciosa) and present in smaller amounts in some other plants. It is the principal active studied for banaba's blood glucose effects.

Evidence for 1 use

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Postprandial blood glucose support

Limited Evidence

Small RCTs using banaba extract standardized to corosolic acid show modest reductions in postprandial blood glucose.

How it works

In cell and animal studies, corosolic acid promotes translocation of GLUT4 glucose transporters to the cell surface, supports insulin signaling, and inhibits enzymes involved in carbohydrate digestion. Small human trials show modest reductions in postprandial glucose at the standardized doses commonly delivered by banaba extracts.

Dosage

Supplements typically supply 1-10 mg of corosolic acid per day, usually as banaba leaf extract standardized to 1-3% corosolic acid.

When and how to take it

Often taken before carbohydrate-containing meals to support postprandial glucose.

2 commercial forms

Compare the main delivery options and what they’re best suited for.

Banaba leaf extract standardized to corosolic acid

Most common commercial source.

Lipophilic; absorption may improve with food containing fat.

Isolated corosolic acid

Rare in finished products.

Limited human pharmacokinetic data.

Safety

Generally well tolerated at typical doses. Mild GI symptoms occasional. Long-term high-dose human data are limited.

Who should be cautious

Caution with insulin or oral diabetes medications because of additive glucose lowering. Pregnancy and breastfeeding data are insufficient.

Interactions

May add to blood-glucose-lowering effects of antidiabetic medications. Monitor blood sugar when combining.

Food sources

Banaba leaf tea

Amount
varies
%DV
—

Frequently asked questions

Is corosolic acid a drug?⌄

No. It is a plant compound sold as a dietary supplement, not an approved medication.

How much corosolic acid is in a typical banaba product?⌄

Many products label extract standardized to 1-3% corosolic acid, delivering 1-10 mg per dose.

References

corosolic acid on Wikidata — Wikidata link

corosolic acid (ChEBI:67895) — ChEBI link

corosolic acid (PubChem CID 6918774) — PubChem link

corosolic acid on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on corosolic acid (PubMed search) — PubMed link

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.