Benefits
Postprandial Glucose Spike Reduction
The Lown 2017 RCT (n=37, crossover) showed Reducose® 250 mg with 50g maltodextrin reduced glucose iAUC by ~40% and insulin iAUC by ~40% vs. placebo. The Thondre 2021 sucrose RCT (n=38) similarly showed glucose iAUC -42% (p=0.001) and insulin iAUC -40% (p<0.001). Effects are most pronounced acutely with carbohydrate-containing meals.
Postprandial Insulin Reduction
By blunting glucose spikes, mulberry extract reduces the corresponding insulin response. This may benefit insulin-resistant individuals and those targeting metabolic flexibility. The Lown and Thondre trials both showed proportional reductions in insulin AUC.
Possible Type 2 Diabetes Glycemic Support
The Hwang 2016 RCT in IGT patients showed glucose suppression. Mehrabani 2022 (n=60 T2DM, 12 weeks) found 300 mg twice daily improved HDL cholesterol, insulin, and MDA (oxidative stress) but did not significantly affect other metabolic markers. The 2022 Korean systematic review supports modest postprandial glucose effects but notes evidence quality limitations.
Carbohydrate Digestion Modulation
By inhibiting α-glucosidase enzymes, mulberry extract reduces digestion of complex carbohydrates and disaccharides (sucrase, maltase, isomaltase). This is the same mechanism as the prescription drug acarbose (Precose®), though mulberry extract has less potent and shorter-duration effects.
Weight Management Adjunct (Speculative)
By reducing postprandial glucose/insulin spikes, mulberry extract may indirectly support weight management — particularly in carbohydrate-heavy diets. Direct weight-loss RCTs with mulberry as primary intervention are limited; treat as a metabolic adjunct rather than weight-loss agent.
Mechanism of action
α-Glucosidase Inhibition (DNJ)
1-Deoxynojirimycin (DNJ) is an iminosugar that competitively inhibits intestinal α-glucosidases (sucrase, maltase, isomaltase). This slows the conversion of disaccharides and starch to absorbable monosaccharides, reducing the speed and magnitude of glucose absorption. Mulberry extract 1000-fold diluted has been shown to inhibit sucrase 96%, maltase 95%, isomaltase 99%.
Reduced Postprandial Glucose Excursion
By delaying carbohydrate digestion, mulberry extract flattens the postprandial glucose curve — both reducing peak glucose and delaying its time-to-peak. This directly mimics acarbose's mechanism of action, though with different potency profile and food synergies.
Reduced Insulin Demand
Lower glucose excursions trigger smaller insulin responses. Over time, reduced insulin demand may help preserve beta-cell function and reduce insulin-driven processes (lipogenesis, hunger signaling). The Lown and Thondre trials documented proportional insulin AUC reductions alongside glucose effects.
Possible GLUT4 Translocation Effects
Beyond α-glucosidase inhibition, gallic acid in mulberry leaves shows GLUT4 translocation effects in vitro — potentially enhancing peripheral glucose disposal independent of insulin. This adds a second mechanism beyond intestinal absorption blockade.
Antioxidant and Anti-Inflammatory Activity
Mulberry leaf phenolics (quercetin, kaempferol, rutin, chlorogenic acid) provide antioxidant and anti-inflammatory effects in vitro and in animal models. The Mehrabani 2022 trial showed reduced MDA (a lipid peroxidation marker) in T2DM patients, consistent with this mechanism.
Clinical trials
Double-blind, randomized, repeat-measure phase 2 crossover trial at Functional Food Centre, Oxford Brookes University. Three doses of mulberry-extract (Reducose® 5% DNJ — 125 mg, 250 mg, 500 mg) vs. placebo with 50 g maltodextrin in normoglycaemic healthy adults. (Lown, Fuller, Lightowler, Fraser, Gallagher, Stuart, Byrne 2017, PLoS One)
37 normoglycaemic healthy adults aged 19-59, BMI 20-30 kg/m². Crossover design.
Significant dose-dependent reductions in postprandial glucose (pIAUC) and insulin (pIAUC) over 120 minutes vs. placebo. Mulberry extract was well tolerated. Established Reducose® dose-response for glucose-spike reduction.
Randomized, double-blind clinical trial of standardized extract from Morus alba leaves (SEMA). α-glucosidase inhibitory effect compared to acarbose; acute oral toxicity assessment; clinical evaluation in patients with impaired glucose tolerance. (Hwang, Li, Lim, Wang, Hong, Huang 2016, Evid Based Complement Alternat Med)
Patients with impaired glucose tolerance (IGT). Animal toxicology + human clinical phases.
SEMA inhibited α-glucosidase at 4× higher levels than acarbose (positive control) in vitro, in concentration-dependent manner. Blood glucose suppression demonstrated in vivo and in IGT patients. Safe at tested doses without observable toxicity in 14-day animal observation.
Randomized, double-blind, placebo-controlled trial of Morus alba extract (300 mg twice daily) vs. placebo for 12 weeks in patients with type 2 diabetes mellitus. Primary outcomes: liver enzymes, inflammation/oxidative stress biomarkers, insulin metabolism, lipid profiles. (Mehrabani, Asemi, Vahidi, Khoroushi, Ghasemi, Ataee, Tahbaz, Najafzadeh-Moghaddam 2022, Complement Ther Med)
60 patients with T2DM (30 per arm). 12-week intervention.
12-week Morus alba extract had beneficial effects on HDL cholesterol, insulin, and MDA (malondialdehyde — oxidative stress marker) vs. placebo, but did NOT affect other metabolic profiles (fasting glucose, total cholesterol, LDL, triglycerides). Limited effect size; supports mulberry as a potential adjunct rather than primary diabetes intervention.
About this ingredient
White mulberry (Morus alba) is a deciduous tree native to East Asia, traditionally cultivated for silkworm food (silk industry) and used in traditional Chinese medicine for diabetes, cough, and other conditions. The principal hypoglycemic bioactive is 1-deoxynojirimycin (DNJ), an iminosugar that competitively inhibits intestinal α-glucosidase enzymes (sucrase, maltase, isomaltase). Standardized commercial extracts (Reducose®) typically contain 4.5-5.5% DNJ.
Other bioactives include gallic acid (which may enhance GLUT4 translocation), chlorogenic acid, and flavonoids (quercetin, rutin, kaempferol). EVIDENCE: Multiple RCTs (Lown 2017, Thondre 2021, Hwang 2016, Mehrabani 2022) support modest postprandial glucose-lowering effects. The 2022 Korean systematic review concluded mulberry CAN reduce postprandial glucose and insulin levels but noted insufficient evidence for being an effective intervention for clinical diabetes management.
Effects are real but modest. SAFETY: Excellent short-term safety. Hypoglycemia risk when combined with insulin/sulfonylureas.
NOT a substitute for prescribed diabetes medications. Best used pre-meal as a metabolic adjunct in prediabetes/early T2DM under physician guidance.