Trehalose, a low-cost sugar used as a food ingredient, drew longevity interest because in cells and animals it appears to help clear damaged proteins — an effect never measured in a person. Replacing glucose with it flattens a meal's blood sugar rise, and as a drink it improves output late in endurance exercise. A gut enzyme splits most of an oral dose into glucose; large doses reliably cause digestive upset. (Full Review)

Protocol

Low metabolic dose

3.3 g/day

Taken with a meal for 12 weeks; the dose of the glucose-tolerance and fracture-healing trials

Substitution dose

25 g

A single serving replacing an equivalent amount of glucose

Exercise dose

30 g per hour

As a drink during endurance exercise

Time to effect

After-meal glucose

Immediate

Within the same meal, when trehalose replaces glucose

Exercise performance

Same session

Improved time-trial work after 100 minutes of cycling

Bone healing, glucose tolerance, inflammation

12 weeks

The realistic trial length for anything beyond a single meal

Benefits

High: Lower after-meal glucose and insulin response when trehalose replaces glucose; improved exercise performance in the later stages of prolonged exercise

Medium: Faster radiographic bone healing and better hip function after hip fracture; comparable periodontal outcomes as a subgingival air-polishing powder

Low: Relief of dry eye disease symptoms with topical trehalose; improved oral glucose tolerance after sustained daily intake; reduced C-reactive protein in type 2 diabetes; improved resistance-artery endothelial function in middle-aged and older adults; stabilised ataxia scores in spinocerebellar ataxia type 3

Speculative: Enhanced autophagy and clearance of misfolded proteins; lifespan extension in model organisms

Contraindications

Documented trehalase deficiency or trehalose intolerance

Recent Clostridioides difficile infection, within 90 days, or recurrent infection

Active diarrhoeal illness, short bowel, or small intestinal bacterial overgrowth

Intravenous trehalose outside a clinical trial

Key Interactions

Theoretical (inferred from mechanism)

Alpha-glucosidase inhibitors (acarbose)

Metformin

Insulin and sulfonylureas (glimepiride, glipizide)

GLP-1 receptor agonists (semaglutide, liraglutide)

Osmotic laxatives and sugar alcohols (lactulose, erythritol, sorbitol)

Berberine and fermentable fibre supplements (inulin)

Broad-spectrum antibiotics (clindamycin, ciprofloxacin)

Fasting, fasting-mimicking and ketogenic protocols

Risk & Side Effects

High: Dose-dependent gastrointestinal intolerance

Medium: Serious adverse events with high-dose weekly intravenous trehalose

Low: Caloric and glycemic load at supplement-level doses; promotion of hypervirulent Clostridioides difficile

Speculative: Autophagic flux blockade and increased protein aggregation

Monitoring

Marker	Target	Why
Two-hour plasma glucose, 75 g oral glucose tolerance test	No established target — track the change from the individual's own baseline	Expected to change; glucose-tolerance endpoint
Alanine aminotransferase	7–56 U/L (standard reference range)	Liver safety check
High-sensitivity C-reactive protein	No established target — track the change from the individual's own baseline	Expected to change; inflammation
Body weight	Not specified in the ER	Checks whether added calories offset the intended effect

Cadence: Weight and digestive tolerance weekly during titration, then the full panel at 12 weeks and every 6 to 12 months thereafter if use continues

Qualitative Assessment

Digestive comfort: bloating, flatulence and abdominal cramping
Stool form and frequency
Perceived energy levels, which should not be read as a treatment effect
Eye comfort and dryness, where topical trehalose is being used

Trehalose for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment