White Mulberry Leaf
Summary
White mulberry leaf contains DNJ, which slows carbohydrate digestion. Small crossover trials found that 200–500 mg of a 5% DNJ extract taken with a carbohydrate load cut the glucose rise by about 14–42% (grade B). Longer-term fasting glucose and HbA1c effects are small and less consistent (grade C). Digestive upset is the main side effect.
Key facts
- 250 mg of an extract standardized to 5% DNJ (12.5 mg DNJ) per carbohydrate load in the main trials[4][5][6]
- Pooled data from 12 trials (615 people) showed fasting glucose about 0.47 mmol/L lower and HbA1c about 2.9 mmol/mol lower[2]
- Bloating, gas, loose stools or constipation; low blood sugar is a possible risk alongside glucose-lowering medicines[1][3]
- 6 graded human outcomes on this page
- October 13, 2026
How it works
EstablishedDNJ resembles glucose and inhibits gut enzymes (alpha-glucosidases) that break down sugars and starch, so carbohydrate is absorbed more slowly. A breath-test study in people confirmed lower starch digestion and absorption after a single dose; effects on insulin secretion are less clear.[7][4][5]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Blood sugar | Grade B | Improved | Crossover RCT · n = 38 · 2021 | 5 rows |
| Carbohydrate absorption | Grade D | Improved | Crossover RCT · n = 25 · 2017 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Post-meal glucose and insulin after a sucrose drink | Improved | Grade B | Crossover RCT · n = 38 · 2021 Healthy adults (UK) Form: Reducose mulberry leaf extract (5% DNJ) · Dose: 250 mg blended into 75 g sucrose · Duration: Single dose, 120-minute test Glucose incremental area was 42% lower and insulin incremental area 40% lower than with sucrose alone; no adverse events were reported. | 33858439 (opens PubMed)Source [5] |
| Post-meal glucose and insulin after maltodextrin (three extract doses) | Improved | Grade B | Crossover RCT · n = 37 · 2017 Healthy normoglycaemic adults aged 19–59, BMI 20–30 (UK) Form: Reducose water extract of mulberry leaf standardized to 5% DNJ · Dose: 125, 250 or 500 mg (6.25, 12.5 or 25 mg DNJ) with 50 g maltodextrin · Duration: Single doses, 120-minute tests Glucose rise (positive incremental area) was 14% lower with 250 mg and 22% lower with 500 mg than placebo; 125 mg was not significant. Insulin rise fell about 24–25% at the two higher doses. Gastrointestinal symptoms did not differ from placebo. | 28225835 (opens PubMed)Source [4] |
| Post-meal glucose and insulin after a mixed meal (three doses) | Improved | Grade B | Crossover RCT · n = 37 · 2024 Healthy adults (UK) Form: Reducose mulberry leaf extract capsules · Dose: 200, 225 or 250 mg before a meal of 150 g white bread with egg mayonnaise · Duration: Single doses, 3-hour tests All three doses lowered the 2-hour glucose incremental area by 30–33% and the insulin incremental area by 31–38% versus placebo. | 38892603 (opens PubMed)Source [6] |
| Fasting glucose, HbA1c and fasting insulin | Improved | Grade C | Meta-analysis · n = 615 · 2023 Adults in 12 randomized trials, healthy and with raised glucose Form: Mulberry leaf or mulberry leaf extract (various preparations) · Dose: Varied by trial · Duration: Varied; subgroup of 8 weeks or longer Fasting glucose fell by 0.47 mmol/L, HbA1c by 2.92 mmol/mol and fasting insulin by 0.58 µIU/mL. Effects were larger in trials of 8 weeks or more and in people with baseline fasting glucose above 6.1 mmol/L. | 36644880 (opens PubMed)Source [2] |
| Metabolic markers over 12 weeks in type 2 diabetes | Mixed | Grade D | RCT · n = 60 · 2022 Adults with type 2 diabetes (Iran) Form: Morus alba leaf extract · Dose: 300 mg twice daily · Duration: 12 weeks Insulin and malondialdehyde fell and HDL cholesterol rose versus placebo; other metabolic markers measured did not change. | 35623877 (opens PubMed)Source [8] |
| Starch digestion and absorption after a cornflake meal (13C breath test) | Improved | Grade D | Crossover RCT · n = 25 · 2017 Healthy young adults aged 19–27 (Poland) Form: Mulberry leaf extract · Dose: Extract providing 36 mg DNJ with 50 g cornflakes and milk · Duration: Single dose, one week apart Cumulative 13C recovery was lower than with placebo (median 13.9% vs 17.2%), indicating less starch digested and absorbed, from 120 minutes after the meal. | 28501729 (opens PubMed)Source [7] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Leaf extract standardized to 5% DNJ (e.g. Reducose) | Varies[4][9] | Its studied action is on carbohydrate digestion in the gut, so in trials a single dose was taken with the carbohydrate load it was meant to affect.[4][7] | Gastrointestinal symptoms did not differ from placebo at 125–500 mg in a single-dose trial, and no adverse events were reported in a sucrose trial.[4][5] | Post-meal glucose and insulin (single doses of 200–500 mg) |
| Dried mulberry leaf powder | Varies[3] | No head-to-head human data against DNJ-standardized extracts.[3] | Bloating, flatulence and loose stools were the most common adverse events over 12 weeks.[3] | Post-meal glucose dose-finding and 12-week glucose markers (12 mg DNJ three times daily) |
| Unstandardized or ratio extracts (e.g. 5:1) | Varies[10] | No head-to-head human data against DNJ-standardized extracts.[10] | No trial data specific to these products.[10] | Not directly studied; DNJ dose cannot be worked out from the label |
Studied doses
Doses studied in human trials ranged from 125–500 mg of a 5% DNJ extract (6–25 mg DNJ) as a single dose with a carbohydrate load, to 300 mg of leaf extract twice daily or leaf powder giving 12 mg DNJ three times daily for 12 weeks. About 12 mg DNJ was the smallest effective dose with a sugar or maltodextrin drink in two trials, and 200 mg of the same extract also lowered the glucose rise after a mixed meal.[3][4][5][6][8]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Medicines
- Diabetes medicinesNIH fact sheetNCCIH lists a potential risk of low blood sugar when white mulberry leaf is used with diabetes medications, because it lowers post-meal glucose. No controlled interaction study was found.[1]
Who should be careful
- People on glucose-lowering medicines
- NCCIH flags a potential risk of low blood sugar when combined with diabetes medications.[1]
- Pregnancy and breastfeeding
- NCCIH says little is known about whether white mulberry leaf is safe during pregnancy or breastfeeding.[1]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
- Check the DNJ contentTrial products gave 12.5 mg DNJ per 250 mg capsule (5% DNJ). Some labels state 5% DNJ; others list only an extract ratio such as 5:1 with no DNJ amount, so the DNJ dose is unknown.[4][9][10]
- Label dose vs studied doseA 250 mg capsule at 5% DNJ matches the main trial dose per meal. In trials it was taken with the carbohydrate load, not at a separate time of day.[4][5][9]
- Leaf vs fruitThe trials tested leaf preparations. NCCIH notes there is insufficient reliable safety information on white mulberry berries.[1][2]
Cost per studied dose, without the sales pitch
Compare any product you already have by the amount it delivers, not by capsule count or front-of-pack weight.
Cost per studied dose
Enter the price, servings and the amount per serving from your label.
Frequently asked questions
Does white mulberry leaf lower blood sugar?
Mainly after meals. Small crossover trials found a 5% DNJ extract taken with a carbohydrate load cut the glucose rise by about 14–42%. Pooled longer-term data show small drops in fasting glucose and HbA1c.[4][5][6][2]
How much DNJ was used in studies?
The main trials used 250 mg of extract standardized to 5% DNJ, which is 12.5 mg DNJ, with each carbohydrate load. About 12 mg DNJ was the smallest effective dose with a sugar or maltodextrin drink in two trials; in a mixed-meal trial, 200 mg of the same extract also worked.[4][3][6]
When was it taken in trials?
With or just before the carbohydrate meal or drink, because it acts on digestion of that meal.[5][6]
What are the side effects?
Bloating, gas, loose stools and constipation are the most common. Studies of up to 12 weeks reported no serious harms.[1][3]
Can it be combined with diabetes medication?
NCCIH warns of a potential risk of low blood sugar when white mulberry leaf is used with diabetes medications.[1]
Is mulberry fruit the same as mulberry leaf?
No. The trials tested leaf preparations, and NCCIH notes there is insufficient reliable safety information on the berries.[1]
Sources
- [1]White Mulberry Leaf: Usefulness and Safety. NCCIH (National Center for Complementary and Integrative Health), 2023. fact-sheet
- [2]Effect of mulberry leaf or mulberry leaf extract on glycemic traits: a systematic review and meta-analysis.. Food Funct, 2023. meta-analysis
- [3]A randomized controlled study of dose-finding, efficacy, and safety of mulberry leaves on glycemic profiles in obese persons with borderline diabetes.. Complement Ther Med, 2020. RCT
- [4]Mulberry-extract improves glucose tolerance and decreases insulin concentrations in normoglycaemic adults: Results of a randomised double-blind placebo-controlled study.. PLoS One, 2017. crossover-RCT
- [5]Mulberry leaf extract improves glycaemic response and insulaemic response to sucrose in healthy subjects: results of a randomized, double blind, placebo-controlled study.. Nutr Metab (Lond), 2021. crossover-RCT
- [6]Understanding the Impact of Different Doses of Reducose® Mulberry Leaf Extract on Blood Glucose and Insulin Responses after Eating a Complex Meal: Results from a Double-Blind, Randomised, Crossover Trial.. Nutrients, 2024. crossover-RCT
- [7]Mulberry leaf extract decreases digestion and absorption of starch in healthy subjects-A randomized, placebo-controlled, crossover study.. Adv Med Sci, 2017. crossover-RCT
- [8]Morus Alba leaf extract affects metabolic profiles, biomarkers inflammation and oxidative stress in patients with type 2 diabetes mellitus: A double-blind clinical trial.. Clin Nutr ESPEN, 2022. RCT
- [9]White Mulberry Leaf (ProCaps Laboratories), DSLD label 275214: 250 mg leaf extract standardized to 5% 1-deoxynojirimycin per capsule. NIH Office of Dietary Supplements, Dietary Supplement Label Database, 2022. label
- [10]White Mulberry Leaf Extract (NusaPure), DSLD label 247129: 500 mg 5:1 leaf extract per capsule, no DNJ content stated. NIH Office of Dietary Supplements, Dietary Supplement Label Database, 2022. label
What changed
- Independent review: "smallest effective dose about 12 mg DNJ" was overstated; the 2024 mixed-meal trial (PMID 38892603) found 200 mg of the same extract effective. All PMIDs re-checked.
- Adversarial review pass: every evidence row, key fact, form, label line, FAQ and insight re-read against its PubMed abstract, PMC full text, fact sheet, FDA page or DSLD label; all PMIDs re-checked by esummary (titles and years match; no retraction or expression-of-concern flags). Fixed: removed unsourced statements on leaf DNJ variability and powder dose, reworded the gut-action note, dropped an inferred side-effect explanation. Page set indexable.
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year from the record) and abstracts read for each cited row; Reducose doses taken from PMC full texts (PMC5321430, PMC8047566). Label amounts from the NIH Dietary Supplement Label Database. Safety and interaction wording from the NCCIH fact sheet (updated September 2023). The 2020 Thai trial is cited for dose and tolerability only because its abstract gives no participant count.