A long-approved diabetes medication that slows starch digestion, flattening post-meal blood sugar and lowering the chance that borderline-high blood sugar progresses to diabetes. It modestly improves weight and blood fats. Longevity interest rests on longer-lived mice, unproven in people. Its main downside is gas, bloating, and loose stools, which ease over time. (Full Review)

Protocol

Starting Dose

25 mg once daily

With the first bite of the largest meal; titrate every 1–2 weeks based on tolerance.

Target Dose

50–100 mg three times daily

Maximum labeled dose 100 mg three times daily (50 mg three times daily if under 60 kg).

Timing

First bite of a starch meal

Dosed per meal, not at a fixed clock time; longevity-oriented use sometimes concentrates a single dose on the largest starch meal.

Time to effect

Glucose Flattening

Immediate

Occurs with the very first dose at a meal.

HbA1c Change

8–12 weeks

Measurable changes in HbA1c (average blood sugar).

Longevity Effect

Long-term, unproven

Any longevity-relevant effect, if it exists in humans, would be a long-term, currently unproven proposition.

Benefits

High: Reduction of post-meal glucose and insulin spikes; prevention of progression from prediabetes to diabetes

Medium: Modest weight and triglyceride reduction; improved metabolic and inflammatory markers

Low: Lifespan and healthspan extension

Speculative: Gut microbiome and short-chain fatty acid benefits; cardiovascular risk reduction

Contraindications

Inflammatory bowel disease

Colonic ulceration

Partial intestinal obstruction or predisposition to it

Chronic digestion or absorption disorders

Cirrhosis

Significant renal impairment (creatinine >2 mg/dL or markedly reduced eGFR)

Pregnancy or breastfeeding

Key Interactions

Insulin and insulin secretagogues (sulfonylureas such as glipizide, glimepiride; meglitinides such as repaglinide)

Other glucose-lowering agents (metformin, SGLT2 inhibitors such as empagliflozin, GLP-1 receptor agonists such as semaglutide)

Digestive enzyme supplements (pancreatin, amylase-containing products) and activated charcoal

Digoxin

Over-the-counter antacids and simethicone

Supplements (berberine, cinnamon extract, white kidney bean/Phaseolus vulgaris extract, chromium)

Risk & Side Effects

High: Gastrointestinal side effects

Medium: Elevated liver enzymes

Low: Hypoglycemia in combination and its altered treatment

Speculative: Nutrient and long-term metabolic effects

Monitoring

Marker	Target	Why
Fasting glucose	70–85 mg/dL	Baseline metabolic health and treatment tracking
HbA1c	<5.4%	Average blood sugar over ~3 months
Post-meal (2 h) glucose	<120 mg/dL	Direct readout of acarbose's core action
ALT / AST (liver enzymes)	ALT <25 U/L (men), <20 U/L (women)	Screen for the reversible liver-enzyme elevation linked to acarbose
Fasting triglycerides	<80 mg/dL	Tracks the modest lipid benefit and metabolic status
Fasting insulin	2–5 µIU/mL	Assesses insulin resistance, which acarbose can improve
eGFR / creatinine	eGFR >90 mL/min/1.73m²	Safety screen; acarbose metabolites are renally cleared

Cadence: Liver enzymes every 3 months during the first year (especially at higher doses); HbA1c and fasting glucose at ~3 months, then every 6–12 months; post-meal glucose reviewed periodically.

Qualitative Assessment

Digestive comfort — degree of flatulence, bloating, and stool changes, which guide dose titration
Energy levels and post-meal alertness — reduced post-meal glucose crashes may improve steadiness of energy after starchy meals
Appetite and satiety patterns — slowed carbohydrate absorption can shift how full and how long-lasting a meal feels

Acarbose for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment