ModerateSynergy
Berberine
Both may lower glucose and can increase hypoglycemia risk when stacked.
Recommendation: Monitor glucose and avoid high-dose stacking with diabetes medications.
Banaba Leaf (Corosolic Acid)
Herb ·Emerging evidence ·Reviewed May 2026
Banaba leaf extract from Lagerstroemia speciosa is standardized for corosolic acid and used for glucose and insulin-sensitivity support. Early human studies suggest possible postprandial and fasting glucose benefits, but the evidence base is smaller than for mainstream diabetes therapies. Product standardization and glucose monitoring are central to safe use.
What it's good for
The bottom line
Evidence rating emerging. Most-documented uses: may support fasting glucose control, may blunt postprandial glucose rise, may improve insulin sensitivity markers. 3 sources indexed (2006–2012), with 3 interaction records on file.
The science
How it works, mechanistically.
Core mechanism
Corosolic acid and ellagitannin constituents may stimulate GLUT4 translocation, improve cellular glucose uptake, inhibit alpha-glucosidase and alpha-amylase activity, and influence PPAR and AMPK-related metabolic signaling. These effects are biologically plausible for post-meal glucose control but vary by extract chemistry. Because it can lower glucose, additive effects with other glucose-lowering agents are clinically relevant.3,1
Class
Corosolic-acid glucose support extract
Found in food
None as a common food; used as leaf tea or extract
Low-status signs
None - banaba is not an essential nutrient and has no deficiency state
Absorption
Water-soluble; take with food
Dosing
Dosing & protocol.
Common range
24-48 mg/day corosolic-acid standardized extract, or 500-1,000 mg/day banaba leaf extract depending on standardization
Recommended form
Leaf extract standardized to corosolic acid with disclosed percentage
Take with meals for glucose support. Extracts vary substantially, so standardization matters more than total milligrams.
Forms
Forms & what to buy.
Ranked by evidence and value.
Corosolic Acid Standardized Extract Recommended
Best matches human glucose studies when standardization is clear. Take with meals.
Banaba Leaf Capsule
Less predictable unless extract ratio and corosolic acid are stated. Take with meals.
Banaba Leaf Tea
Low and variable active compound delivery. Drink with or after meals.
Cost
What it actually costs.
Real-world pricing across three quality tiers. Assumes Corosolic acid standardized capsule.
BudgetBest value
$5 /mo
$0.18 per dose
Mid
$14 /mo
$0.45 per dose
Premium
$29 /mo
$0.95 per dose
Costs depend heavily on disclosed corosolic acid standardization. Updated 2026-06-04.
Goals
Goal-based dosing.
Postprandial Glucose Support
Dose: 24-48 mg corosolic-acid equivalent daily1,3
Timing: With higher-carbohydrate meals
Monitor glucose response rather than assuming benefit.
Fasting Glucose Support
Dose: 500-1,000 mg/day standardized leaf extract1,3
Timing: Divided with meals
Recheck fasting glucose and HbA1c after 8-12 weeks.
Insulin Sensitivity Support
Dose: 24 mg corosolic-acid equivalent daily
Timing: With meals
Best paired with resistance training and weight management when appropriate.
Lab work
Markers to track.
What to test, the optimal window inside the conventional range, and how long a response takes.
Fasting Plasma Glucose FPG
May modestly lower fasting glucose and HbA1c in responders.1,3
Optimal
70–90 mg/dL
Conventional
70–99 mg/dL
Responds in
8-12 weeks
70optimal99
Check fasting glucose at baseline and after a consistent trial; monitor more closely if using glucose-lowering medication.
Hemoglobin A1cFasting insulinTriglycerides
Hemoglobin A1c HbA1c
May modestly lower HbA1c when glycemic control improves.
Optimal
4.8–5.4 %
Conventional
4–5.6 %
Responds in
12 weeks
4optimal5.6
HbA1c reflects roughly 2-3 months of glycemia and should not be interpreted alone in anemia or altered red cell turnover.
Fasting plasma glucosePostprandial glucoseFasting insulin
Why people use it
Symptoms it's matched to.
Where this appears in the symptom-to-supplement map, ranked by relevance.
Post-meal glucose spikes
48% relevance
May enhance glucose uptake and slow carbohydrate digestion.1,3
MetabolicEmerging evidenceCorosolic acid standardized extract
Response should be measured.
High fasting glucose
42% relevance
May support insulin sensitivity and glucose utilization.1,3
MetabolicEmerging evidenceStandardized extract with meals
Evidence base is small.
Insulin resistance pattern
40% relevance
May influence GLUT4 and AMPK-related pathways.
MetabolicEmerging evidenceCorosolic acid extract
Lifestyle measures remain primary.
Safety
Full safety detail.
Side effects
- Mild stomach upset
- Dizziness or symptoms of low glucose
- Headache
- Possible additive glucose lowering with diabetes medications
Interactions
Interaction records.
ModerateSynergy
Alpha-Lipoic Acid
Both may improve insulin sensitivity and glucose disposal.
Recommendation: Start one product at a time and monitor glucose.
InfoSynergy
Psyllium Husk
Psyllium slows carbohydrate absorption and may complement banaba for post-meal glucose.
Recommendation: Take psyllium with adequate water and separate medications as needed.
Search all 3 interaction records for Banaba Leaf (Corosolic Acid) →
Sources
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Randomized controlled trials
1- 1A corosolic acid-containing extract from Lagerstroemia speciosa leaves lowers glucose levels in humansNeeds reviewNo linkFukushima M et al. · Journal of Nutritional Science and Vitaminology · 2006
Corosolic-acid standardized banaba extract was associated with lower blood glucose after administration.
Reviews & position papers
2- 2The antidiabetic and anti-obesity effects of Lagerstroemia speciosa L. and its active constituentsNeeds reviewNo linkStohs SJ et al. · Phytotherapy Research · 2012
Evidence supports biologic plausibility but calls for better standardized clinical trials.
- 3Anti-diabetes and anti-obesity activity of Lagerstroemia speciosaNeeds reviewNo linkKlein G et al. · Evidence-Based Complementary and Alternative Medicine · 2007
Review summarized corosolic acid, ellagitannins, glucose transport, and enzyme inhibition mechanisms.
Keep exploring
Deep dives & adjacent profiles.
This page is educational. Do not start, stop, or change a supplement or medication based on it without checking with a qualified healthcare professional.
Use this with your stack
Banaba Leaf (Corosolic Acid) in NutriStack.
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.