Alpha-Galactosidase
Also known as: α-galactosidase, Beano®, AGAL
α-galactosidase hydrolyses the α-1,6 galactosidic bonds linking galactose to sucrose in raffinose-family oligosaccharides (RFOs). Activity is measured in Galactose Activity Units (GalU).
Last reviewed: 2025-01-15 · 1 indexed study
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Overview
An enzyme derived from Aspergillus niger that breaks down indigestible oligosaccharides (raffinose, stachyose, verbascose) found in beans, lentils, and cruciferous vegetables before they reach the colon to be fermented into gas.
Mechanism & Function
Mechanism of Action
Hydrolyses RFOs in the small intestine into monosaccharides that can be absorbed, preventing their delivery to colonic bacteria that ferment them into hydrogen, methane, and CO₂.
Physiological Role
Pre-emptively digests fermentable oligosaccharides that humans lack the brush-border enzyme to digest.
Primary Pathways
Performance / Health Relevance
Reduces flatulence and bloating from high-fibre/legume-heavy diets common in plant-based athletes, supporting comfort during training.
Evidence Review
No meta-analyses or systematic reviews indexed for this ingredient yet.
Dimensions marked N/A have no indexed evidence of that class. They are shown as unavailable rather than scored.
Practical Use & Dosage
- Minimum Effective Dose
- 300 GalU per high-RFO meal
- Optimal Range
- 300–1200 GalU at the start of the meal
- Upper / Caution Level
- No established upper limit
- Timing
- With the first bite of beans/legumes/cruciferous vegetables
- Best Format
- Tablet, capsule, or liquid drops
- Bioavailability
- Acts locally; not absorbed.
- Absorption Considerations
- Must be taken with the offending food, not after symptoms appear.
Safety & Interactions
Side Effects
- •Rare allergic reaction to fungal-derived enzyme
Contraindications
- Galactosaemia
Drug Interactions
- •Acarbose (similar mechanism — may reduce diabetes drug effect)
Who Should Avoid
- •Patients with galactosaemia
Monitoring
Diabetics on acarbose should consult a clinician.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Alpha-Galactosidase typically used or indicated?
Alpha-Galactosidase is most commonly used for: Bean & legume tolerance, Cruciferous vegetable bloating, FODMAP-related gas. Pre-emptively digests fermentable oligosaccharides that humans lack the brush-border enzyme to digest.
How does Alpha-Galactosidase work?
Hydrolyses RFOs in the small intestine into monosaccharides that can be absorbed, preventing their delivery to colonic bacteria that ferment them into hydrogen, methane, and CO₂.
What is the recommended dose of Alpha-Galactosidase?
The optimal range is 300–1200 GalU at the start of the meal. with a minimum effective dose of 300 GalU per high-RFO meal. Best taken: With the first bite of beans/legumes/cruciferous vegetables. Upper / caution level: No established upper limit.
What are the side effects of Alpha-Galactosidase?
Reported side effects include: Rare allergic reaction to fungal-derived enzyme. Monitoring: Diabetics on acarbose should consult a clinician.
Does Alpha-Galactosidase interact with medications?
Known or theoretical interactions: Acarbose (similar mechanism — may reduce diabetes drug effect). Always check with a clinician before combining with prescription medication.
Who should avoid Alpha-Galactosidase?
Alpha-Galactosidase is generally not recommended for: Patients with galactosaemia; and Galactosaemia.
How strong is the evidence for Alpha-Galactosidase?
Evidence level: Moderate (overall score 68/100), based on 1 indexed study on SuppIndex.
Research & References (1)
Treatment of gas-related symptoms with alpha-galactosidase: a randomised, placebo-controlled trial
Di Stefano M et al. α-galactosidase significantly reduced flatulence and abdominal pain after a high-RFO meal vs placebo.
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Research Overview
Moderate EvidenceCite this ingredient
One-click citation export in APA, MLA, Chicago, BibTeX, or HTML. The URL below is stable and safe to link.
Stable URL
https://thesuppindex.com/ingredients/alpha-galactosidase
SuppIndex. (2026). Alpha-Galactosidase: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/alpha-galactosidase
Based on 1 indexed studies · Evidence level: Moderate.
Goal Ratings
Stack Compatibility
Combines well with full-spectrum digestive enzyme blends.