Acarbose

Mechanism of Action

Acarbose is a complex oligosaccharide that competitively inhibits alpha-glucosidase enzymes (maltase, isomaltase, sucrase, glucoamylase) in the brush border of the small intestinal enterocytes, delaying the digestion and absorption of dietary carbohydrates. This blunts postprandial glucose and insulin spikes, reducing glycemic variability. In the longevity context, chronic postprandial glucose/insulin reduction mimics aspects of caloric restriction signaling, potentially reducing mTOR activation, AGE formation, and oxidative stress. Undigested carbohydrates reaching the colon serve as prebiotics, increasing short-chain fatty acid (SCFA) production by gut bacteria.

Dosing Protocol

Notes

Acarbose extended lifespan by 22% in male and 5% in female HET3 mice in the NIA Interventions Testing Program at 1000 ppm — one of only a handful of compounds with robust, multi-site replicated lifespan extension. Combined with rapamycin, the effect was additive (19% increase in males, more than either alone). The primary barrier to use is GI side effects — start at 25 mg with one meal and titrate slowly over 4-6 weeks. GI symptoms typically improve as gut microbiome adapts. The gender disparity in mice (much larger effect in males) is noted but not fully understood. Required bloodwork: Fasting glucose, postprandial glucose, HbA1c, liver function panel (AST/ALT) at baseline and every 6 months. Low-carb dieters will see minimal benefit as the mechanism requires carbohydrate substrate. Medical supervision required.

Stacking

• Metformin (complementary glucose-lowering via different mechanism)
• Rapamycin (ITP-validated combination — additive lifespan extension)
• Berberine (alternating, not concurrent — similar glucose-lowering)

Interactions

• Insulin / Sulfonylureas [MEDIUM] — Additive hypoglycemia risk. IMPORTANT: If hypoglycemia occurs while on acarbose, must treat with glucose (dextrose) not sucrose — acarbose blocks sucrose digestion.
• Digestive enzyme supplements (amylase, pancreatin) [MEDIUM] — Digestive enzymes counteract acarbose's mechanism. Avoid concurrent use.
• Activated charcoal / Adsorbents [LOW] — May adsorb acarbose and reduce efficacy.
• Additive effects with other glucose-lowering therapies

Contraindications

• Inflammatory bowel disease (Crohn's, ulcerative colitis)
• Intestinal obstruction or predisposition to obstruction
• Chronic intestinal diseases with maldigestion/malabsorption
• Severe renal impairment (creatinine >2.0 mg/dL)
• Cirrhosis
• Known hypersensitivity to acarbose
• GI intolerance
• IBD or bowel obstruction

Side Effects

• Flatulence and bloating (very common — from colonic fermentation of undigested carbohydrates)
• Diarrhea
• Abdominal pain and cramping
• Elevated liver transaminases (rare, reversible — typically at doses >100 mg TID)

Key Papers

• 10.1111/acel.12898
• 10.1038/s41598-022-11229-1
• 10.1111/acel.13088
• Metabolic and ITP literature on acarbose

Source Quality

FDA-approved pharmaceutical (Precose/Glucobay). Generic acarbose widely available. 25 mg, 50 mg, and 100 mg tablets. Stable at room temperature.

Should Acarbose Be in Your Stack?

Take the free assessment and get personalized recommendations based on your biology and goals.