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acarbose

Precosealpha-glucosidase inhibitor

Acarbose is an oral alpha-glucosidase inhibitor for type 2 diabetes. It slows the enzymes that digest starch and sucrose in the small intestine, so glucose enters the blood more gradually and post-meal blood sugar rises stay smaller. It is used alongside diet and exercise in adults.

This page is based on the FDA label for acarbose, cross-checked with MedlinePlus and the National Cancer Institute dictionary; the mechanism is explained in plain language, and analogies are used only where they stay accurate.

How it works

Explains what the medicine does in the body, not dosing, side effects, or safety.

An analogy

After a starchy meal, the gut is like a conveyor belt that chops long carbohydrate chains into single sugar packets. Acarbose dulls the cutting blades, so packets come off the belt slowly instead of all at once, and the blood sugar counter is not flooded in one rush.

In simple terms

When you eat carbohydrates, enzymes in the small intestine cut them into glucose, which then passes into the blood. Acarbose reversibly blocks those enzymes, especially alpha-glucosidase, so digestion takes longer and glucose is released step by step. The result is a smaller rise in blood sugar after meals, which is the main problem in type 2 diabetes.

In depth

Acarbose is a pseudotetrasaccharide that binds competitively and reversibly to alpha-glucosidases in the brush border of the small intestine, inhibiting the hydrolysis of oligosaccharides and disaccharides into monosaccharides. It also inhibits pancreatic alpha-amylase, delaying the breakdown of complex starches. By postponing carbohydrate digestion, acarbose blunts postprandial glucose and insulin excursions without stimulating insulin secretion, so it does not cause hypoglycemia when used alone.

Target: Alpha-glucosidase

An enzyme on the brush border of the small intestine that breaks oligosaccharides and disaccharides down into absorbable glucose; its activity drives the post-meal rise in blood sugar.

Approved uses

Approved uses differ by country and change over time. Always follow your local prescribing information.

Approved uses in United States

FDAas of Aug 22, 2026
  • As an adjunct to diet and exercise, to improve glycemic control in adults with type 2 diabetes mellitus

Official sources

The statements on this page trace back to these records.

  1. U.S. Food and Drug Administration: acarbose prescribing information

    U.S. Food and Drug Administration · Retrieved Aug 22, 2026

  2. MedlinePlus: acarbose

    MedlinePlus, U.S. National Library of Medicine · Retrieved Aug 22, 2026

  3. National Cancer Institute: acarbose

    National Cancer Institute · Retrieved Aug 22, 2026

Editorial review

Reviewed
Aug 23, 2026
Next review
Feb 23, 2027
Cross-checked by
researcher-regulatory - FDA label · researcher-nlm - MedlinePlus and NCI · editor - plain-language paraphrase and cross-check
Method
independent multi-source collection -> cross-check for agreement -> original English paraphrase -> item-by-item verification against the evidence bundle

MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.