1-Deoxynojirimycin (DNJ)
Also known as: DNJ, 1-deoxynojirimycin, moranoline, mulberry leaf extract alkaloid
Effective Dosage
2.9–10.2 mg per meal based on study doses
What the Science Says
1-Deoxynojirimycin (DNJ) is a natural sugar-like compound found in mulberry leaves and fruit. It works by blocking alpha-glucosidase, an intestinal enzyme that breaks down carbohydrates into glucose — slowing how fast sugar enters your bloodstream after a meal. Multiple clinical trials show it meaningfully reduces post-meal blood glucose and insulin spikes, with effects seen at doses as low as 2.9 mg taken alongside a carbohydrate-rich meal. One small pilot study also found it may reduce the temporary arterial stiffening that follows a blood sugar spike.
What It Doesn't Do
Won't lower fasting blood sugar on its own. Not a substitute for diabetes medication. No evidence it causes meaningful long-term weight loss. Won't work if you take it hours before or after eating carbs — timing with meals is essential. No proven benefit for people eating low-carb diets.
Evidence-Based Benefits
1-Deoxynojirimycin (DNJ) is a natural sugar-like compound found in mulberry leaves and fruit. It works by blocking alpha-glucosidase, an intestinal enzyme that breaks down carbohydrates into glucose — slowing how fast sugar enters your bloodstream after a meal. Multiple clinical trials show it meaningfully reduces post-meal blood glucose and insulin spikes, with effects seen at doses as low as 2.9 mg taken alongside a carbohydrate-rich meal. One small pilot study also found it may reduce the temporary arterial stiffening that follows a blood sugar spike.
Moderate EvidenceEffective at: 2.9–10.2 mg per meal based on study doses
Source: auto-research
Absorption & Bioavailability
Moderate — plasma DNJ levels are measurable after oral intake, but interestingly higher when consumed as mulberry fruit extract than as isolated pure DNJ, suggesting other compounds in the whole extract (like 2-O-alpha-D-galactopyranosyl-DNJ) may act as precursors and enhance absorption.
Red Flags to Watch For
- Most studies use mulberry-derived products, not isolated DNJ supplements — product quality and actual DNJ content in commercial supplements can vary widely
- 29 registered supplement products exist but DNJ content is rarely standardized or verified on labels
- People taking diabetes medications (especially alpha-glucosidase inhibitors like acarbose) should not combine without medical supervision — additive blood sugar lowering could cause hypoglycemia
- Most human trials are short-term (single-meal or crossover designs); long-term safety data from the provided studies is limited
- Animal studies suggest potential liver effects at high doses, but human safety data at typical supplement doses is not well characterized in the provided papers
Products Containing 1-Deoxynojirimycin (DNJ)
See how 1-Deoxynojirimycin (DNJ) is used in these analyzed products:
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-09