Reducose®: Standardized White Mulberry Leaf Extract for Post-Meal Glucose Support

Q: What is Reducose®?

Reducose® is a standardized white mulberry leaf (Morus alba) extract manufactured by Phynova Group Limited, standardized by HPLC to 4.5 to 5.5 percent 1-deoxynojirimycin (DNJ). DNJ slows the action of intestinal alpha-glucosidase, the enzyme that converts dietary carbohydrates into absorbable glucose. Reducose® qualifies as a dietary ingredient under US DSHEA.

Q: How does Reducose® work?

DNJ, the bioactive in Reducose®, is a structural analogue of glucose that competes with carbohydrates for the active site of intestinal alpha-glucosidase. This slows carbohydrate digestion, reduces the rate of glucose absorption, and supports a lower, more gradual post-meal glucose and insulin response.

Q: What dose of Reducose® is effective?

Three randomized controlled trials in healthy adults support 200 to 250 mg per administration when taken before a carbohydrate-containing meal. BIOSTRIPS® delivers 250 mg per serving, an exact match to the highest dose tested in all three trials.

Q: How is Reducose® different from generic white mulberry extract?

Reducose® is standardized to a verified DNJ range of 4.5 to 5.5 percent by HPLC. Generic mulberry leaf products rarely disclose DNJ content, and concentrations vary widely when tested independently. The published clinical trials are specific to the branded, standardized extract and do not transfer to unstandardized products.

Q: Is Reducose® the same as acarbose?

No. Both act on intestinal alpha-glucosidase, but acarbose is a prescription pharmaceutical approved for type 2 diabetes with substantially higher potency. Reducose® is a food-derived dietary ingredient and is not a treatment for any condition.

Q: How does Reducose® compare to berberine or chromium?

They act at different points. Reducose® works in the gut, slowing carbohydrate breakdown before glucose is absorbed. Berberine and chromium act after absorption, on cellular glucose uptake and insulin signalling. Reducose® has the more direct evidence base for post-meal glucose response specifically, with three placebo-controlled human trials at a single standardized dose.

Q: When should I take BIOSTRIPS® Glucose Support?

Take two strips 2 to 3 minutes before the first meal of the day, or before any carbohydrate-heavy meal. The pre-meal timing is a functional requirement, because the active compound must reach the small intestine at the same time as dietary carbohydrates to have any effect.

Q: How long does Reducose® take to work?

It acts on the meal it is taken with, not over weeks. In Thondre 2021, glucose was significantly lower than placebo at 15, 30, 45, and 120 minutes after the dose. There is no loading period, and no cumulative effect is claimed.

Q: Is Reducose® safe?

Three randomized controlled trials tested Reducose® from 125 to 500 mg per administration with no serious adverse events at any dose. The Lown 2017 trial formally assessed gastrointestinal tolerability and found no significant differences from placebo for nausea, cramping, bloating, or flatulence at any dose tested. Reducose® has not been studied in pregnant or lactating women.

Q: Can I take BIOSTRIPS® if I have diabetes or take blood sugar medication?

Persons with diabetes or any blood-glucose condition, and anyone taking glucose-lowering medications such as insulin, sulfonylureas, or metformin, should consult a healthcare provider before use. This product is formulated for healthy adults supporting normal glucose metabolism, not for managing a diagnosed medical condition.

Reducose® white mulberry leaf extract and a BIOSTRIPS® Glucose Support single-strip sachet on white mulberry foliage

Reducose® is a standardized white mulberry leaf (Morus alba) extract, tested by HPLC to 4.5–5.5% 1-deoxynojirimycin (DNJ). It slows the intestinal breakdown of dietary carbohydrates. In three randomized, double-blind, placebo-controlled trials in healthy adults, 250 mg taken before a carbohydrate-containing meal reduced post-meal glucose response by 14–42% and insulin response by 24–40% versus placebo.

By Joanna Bacchus, Certified Nutritional Advisor and Founder

What Is Reducose®?

Reducose® is a registered trademark of Phynova Group Limited, Banbury, Oxfordshire, United Kingdom (company number 05202283). It is a water extract of Morus alba L. leaves, standardized by HPLC to 4.5 to 5.5 percent 1-deoxynojirimycin (DNJ). DNJ is an iminosugar and the primary bioactive responsible for Reducose®'s effect on post-meal glucose.

White mulberry (Morus alba, family Moraceae) has a centuries-long history of use in traditional East Asian medicine for blood sugar support. Reducose® isolates and standardizes this bioactivity through a controlled extraction and quality process. The ingredient qualifies as a dietary ingredient under the US Dietary Supplement Health and Education Act (DSHEA, 21 U.S.C. Section 321(ff)).

The clinical evidence on this page is specific to the Reducose® branded, standardized extract. Unstandardized white mulberry leaf products have variable and often unlisted DNJ content and are not bioequivalent to any of the trials cited here.

Wikipedia: Morus alba
Wikidata: Q157307
Manufacturer: Phynova Group Limited — Reducose®

How Does Reducose® Work?

Three-step diagram showing carbohydrates entering the small intestine, DNJ occupying the alpha-glucosidase active site, and glucose being released more gradually

Intestinal alpha-glucosidase is a brush-border enzyme in the small intestine. It breaks dietary carbohydrates into free glucose for absorption into the bloodstream. Reducose® works by slowing this process.

DNJ is a structural analogue of glucose. It competes with carbohydrates for the active site of intestinal alpha-glucosidase, which slows the breakdown of carbohydrates into absorbable glucose. This supports a more gradual post-meal glucose response. Because insulin release responds to circulating glucose, the clinical trials also measured post-meal insulin markers.

Clinical trials have tested Reducose® against three different carbohydrate substrates: maltodextrin (Lown 2017), sucrose (Thondre 2021), and a mixed-macronutrient white bread meal (Thondre 2024), with consistent glucose and insulin reductions across all three. Wang et al. (2018, Medicine) reported additional activity against maltose in a supporting study using a non-branded mulberry extract.

BIOSTRIPS® strips dissolve in the mouth 2 to 3 minutes before a meal. This pre-meal timing is a functional requirement: alpha-glucosidase inhibition only works when the active compound is present in the small intestine at the same time as dietary carbohydrates.

Clinical Evidence

Three independent randomized, double-blind, placebo-controlled crossover trials in healthy adults have tested Reducose® at the 250 mg dose. All three are published in peer-reviewed journals and indexed on PubMed. All PMIDs below are verified against PubMed.

Lown et al., 2017 — PLoS One — PMID 28225835

Lown M, Fuller R, Lightowler H, Fraser A, Gallagher A, Stuart B, Byrne C, Lewith G. Mulberry-extract improves glucose tolerance and decreases insulin concentrations in normoglycaemic adults: Results of a randomised double-blind placebo-controlled study. PLoS One. 2017;12(2):e0172239. PMID 28225835.

Phase 2 randomised controlled trial, Oxford Brookes University. 37 normoglycaemic adults aged 19–59, BMI 20–30. Reducose® at 125 mg, 250 mg, or 500 mg, or placebo, co-administered with 50 g maltodextrin. At 250 mg: glucose pIAUC −14.0% versus placebo (95% CI −26.0 to −2.0, p=0.022); insulin pIAUC −23.8% (p=0.004). Dose-response confirmed: 125 mg not significant; 500 mg reduced glucose pIAUC −22.0% (p<0.001). No significant gastrointestinal symptom differences versus placebo at any dose.

Thondre et al., 2021 — Nutrition & Metabolism — PMID 33858439

Thondre PS, Lightowler H, Ahlstrom L, Gallagher A. Mulberry leaf extract improves glycaemic response and insulaemic response to sucrose in healthy subjects: results of a randomized, double blind, placebo-controlled study. Nutrition & Metabolism. 2021;18:41. PMID 33858439.

Randomised controlled trial. 38 healthy adults recruited, 36 evaluable, aged 20–58. Reducose® 250 mg or placebo with 75 g sucrose. Glucose iAUC −42% (p=0.001); peak glucose −40% (p<0.001); insulin iAUC −40% (p<0.001); peak insulin −41% (p<0.001). Glucose was significantly lower at 15, 30, 45, and 120 minutes post-dose. No adverse events. This trial's methods section formally documents the Reducose® 4.5 to 5.5 percent DNJ standardisation specification by HPLC.

Thondre et al., 2024 — Nutrients — PMID 38892603 (REDUCE Study)

Thondre PS, Butler I, Tammam J, Achebe I, Young E, Lane M, Gallagher A. 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;16(11):1670. PMID 38892603.

Four-arm crossover randomised controlled trial. 37 healthy adults completed the study. Reducose® at 200 mg, 225 mg, or 250 mg, or placebo, before a mixed meal of 150 g white bread and 50 g egg mayonnaise filler providing 68.7 g carbohydrate, 18.7 g protein, and 10.2 g fat. All three doses significantly reduced glucose iAUC (200 mg: −30%, p=0.003; 225 mg: −33%, p=0.001; 250 mg: −32%, p=0.002) and insulin iAUC (200 mg: −31%, p=0.024; 225 mg: −34%, p=0.004; 250 mg: −38%, p<0.001). The 250 mg dose produced the greatest insulin reduction. This is the most representative trial for real-world use: a normal mixed-macronutrient meal rather than a purified carbohydrate load.

What Dose of Reducose® Is Effective?

The clinically established dose of Reducose® is 200 to 250 mg per administration, taken before a carbohydrate-containing meal. This range is supported by all three randomized controlled trials. The 250 mg dose used in BIOSTRIPS® is the highest tested across all three trials and the dose associated with the greatest insulin reduction in the REDUCE study.

Reducose® is standardized by HPLC to 4.5 to 5.5 percent DNJ. At 250 mg per serving,
BIOSTRIPS® delivers 11.25 to 13.75 mg of DNJ, consistent with the 12.5 mg per serving reported in Lown 2017. Unstandardized white mulberry powders cannot confirm equivalent bioactive delivery.

Study	Reducose® dose	Primary outcome vs placebo	BIOSTRIPS® dose
Lown et al., 2017 PLoS One	250 mg 50 g maltodextrin	Glucose pIAUC −14.0% (p=0.022) Insulin pIAUC −23.8% (p=0.004)	250 mg Exact match
Thondre et al., 2021 Nutr Metab (Lond)	250 mg 75 g sucrose	Glucose iAUC −42% (p=0.001) Peak glucose −40% (p<0.001)	250 mg Exact match
Thondre et al., 2024 Nutrients (REDUCE)	250 mg Mixed-macronutrient meal	Glucose iAUC −32% (p=0.002) Insulin iAUC −38% (p<0.001)	250 mg Exact match

Table 1. Study dose versus BIOSTRIPS® dose.

Why Reducose® Is in BIOSTRIPS® Glucose Support

Reducose® was selected as the primary active ingredient on three grounds: dose match, standardization, and delivery compatibility.

The BIOSTRIPS® serving of 250 mg corresponds exactly to the dose tested in all three published trials. Reducose® is tested by HPLC to a specific DNJ range, while generic mulberry extracts vary in bioactive content and carry no equivalent clinical record.

Alpha-glucosidase inhibition requires the active compound to reach the small intestine at the same time as dietary carbohydrates. An oral dissolving strip taken 2 to 3 minutes before a meal supports that timing reliably, with no water and no swallowing required.

Delivery mechanism and formulation detail: BIOSTRIPS® Glucose Support. Background on the extract: White Mulberry Leaf Extract: A Complete Guide.

Is Reducose® Safe?

Reducose® has been tested in three randomized controlled trials at doses from 125 mg to 500 mg per administration. No serious adverse events have been reported at any dose. The Lown 2017 trial conducted a formal gastrointestinal tolerability assessment and found no significant differences versus placebo at 125, 250, or 500 mg for nausea, cramping, distension, or flatulence.

Trial	Dose / participants	Safety finding
Lown et al., 2017, PLoS One	125–500 mg, n=37	No serious adverse events. No significant GI symptom differences versus placebo at any dose.
Thondre et al., 2021, Nutr Metab	250 mg, n=36	Well tolerated. No adverse events reported.
Thondre et al., 2024, Nutrients	200–250 mg, n=37	Well tolerated across all three dose levels.

Table 2. Safety findings across the three Reducose® trials.

Recommended Use

Adults 18 years and older.
Two strips taken 2 to 3 minutes before the first meal of the day. May also be taken before dinner. Maximum four strips per day.
Not recommended for pregnant or lactating women. Not studied in these populations.

Consult a healthcare provider before use if you are:

Diagnosed with diabetes, pre-diabetes, or any condition affecting blood glucose.
Taking insulin, sulfonylureas, metformin, or any other glucose-lowering medication.
Taking any prescription medication that affects blood sugar or carbohydrate metabolism.

Regulatory Status

Reducose® qualifies as a dietary ingredient under DSHEA (21 U.S.C. Section 321(ff)). All structure/function claims for BIOSTRIPS® Glucose Support are framed under 21 CFR Section 101.93.

Frequently Asked Questions

What is Reducose®?

Reducose® is a standardized white mulberry leaf (Morus alba) extract manufactured by Phynova Group Limited, standardized by HPLC to 4.5 to 5.5 percent 1-deoxynojirimycin (DNJ). DNJ slows the action of intestinal alpha-glucosidase, the enzyme that converts dietary carbohydrates into absorbable glucose. Reducose® qualifies as a dietary ingredient under US DSHEA.

How does Reducose® work?

DNJ, the bioactive in Reducose®, is a structural analogue of glucose that competes with carbohydrates for the active site of intestinal alpha-glucosidase. This slows carbohydrate digestion, reduces the rate of glucose absorption, and supports a lower, more gradual post-meal glucose and insulin response.

What dose of Reducose® is effective?

Three randomized controlled trials in healthy adults support 200 to 250 mg per administration when taken before a carbohydrate-containing meal. BIOSTRIPS® delivers 250 mg per serving, an exact match to the highest dose tested in all three trials.

How is Reducose® different from generic white mulberry extract?