Trehalose
Summary
Trehalose is a sugar made of two glucose units. In two small manufacturer-run trials, swapping sucrose for 3.3–10 g/day of trehalose improved 2-hour glucose only versus baseline or in subgroups. Intravenous trehalose did not slow ALS in a 161-person trial. A 2018 lab study linked trehalose to virulent C. difficile strains; a later review found no proven human link.
Key facts
- A disaccharide of two glucose molecules, split by the gut enzyme trehalase[3]
- 25 g trehalose raised blood glucose and insulin less sharply than 25 g glucose and gave higher GLP-1 later on[3]
- 10 g/day for 12 weeks lowered 2-hour OGTT glucose versus baseline in 34 adults with BMI ≥23[2]
- Weekly intravenous trehalose for 24 weeks: disease rate ratio 0.87, not convincingly better than placebo; serious adverse events 16% vs 7%[5]
- Epidemic C. difficile strains use trehalose in lab and mouse studies; a 2021 review found no proven causal link to human infection[7][8]
- 6 graded human outcomes on this page
- October 13, 2026
How it works
ProposedTrehalose is digested to glucose by trehalase, but more slowly than sucrose or glucose, giving a flatter glucose and insulin curve and a later GLP-1 rise. In cell and animal studies it induces autophagy and stabilises proteins, which prompted trials in neurodegenerative disease; these effects have not been shown in people.[3][10]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Neurodegeneration | Grade C | No effect | RCT · n = 161 · 2025 | 2 rows |
| Bone | Grade D | Improved | RCT · n = 57 · 2026 | 1 row |
| Blood sugar | Grade D | Mixed | RCT · n = 50 · 2020 | 2 rows |
| Exercise | Grade D | Mixed | Crossover RCT · n = 12 · 2021 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Disease progression and survival in ALS (intravenous) | No effect | Grade C | RCT · n = 161 · 2025 Adults with ALS at 60 US sites (120 trehalose, 41 regimen placebo plus shared placebo) Form: Intravenous trehalose (not a supplement form) · Dose: 0.75 g/kg intravenously once weekly · Duration: 24 weeks Disease rate ratio 0.87 (95% credible interval 0.665–1.102); not convincingly better than placebo. Serious adverse events in 16% on trehalose versus 7% on placebo. | 40409314 (opens PubMed)Source [5] |
| Fracture union and hip function after pertrochanteric fracture surgery | Improved | Grade D | RCT · n = 57 · 2026 Adults aged 18–60 after surgery for pertrochanteric hip fracture (Iran); 64 enrolled Form: Trehalose versus sucrose placebo · Dose: 3.3 g/day · Duration: 12 weeks Radiographic union score (+2.09 points) and Harris Hip Score (+8.55 points) were higher than placebo at week 12; pain fell similarly in both groups. | 42243278 (opens PubMed)Source [9] |
| Glucose tolerance in healthy adults | Mixed | Grade D | RCT · n = 50 · 2020 Healthy Japanese adults Form: Trehalose versus sucrose · Dose: 3.3 g/day · Duration: 78 days (12 weeks) No between-group differences in body composition or blood tests. In a subgroup with higher post-meal glucose, 2-hour OGTT glucose was lower with trehalose than sucrose. | 32646428 (opens PubMed)Source [1] |
| Glucose tolerance and waist size in adults with BMI 23 or more | Mixed | Grade D | RCT · n = 34 · 2016 Japanese adults with BMI ≥23 Form: Trehalose versus sucrose · Dose: 10 g/day with meals · Duration: 12 weeks 2-hour OGTT glucose fell versus baseline in the trehalose group; weight, waist and systolic blood pressure differed from sucrose only in a subgroup with higher truncal fat. | 28202842 (opens PubMed)Source [2] |
| Ataxia severity in spinocerebellar ataxia type 3 | No effect | Grade D | RCT · n = 15 · 2024 Adults with spinocerebellar ataxia type 3 (Malaysia), interim analysis Form: Oral trehalose versus maltose · Dose: 100 g/day · Duration: 6 months No effect on ataxia severity versus placebo; executive function changed in exploratory analyses. 100 g/day was well tolerated. The trial stopped early for slow recruitment. | 38843619 (opens PubMed)Source [6] |
| Prolonged exercise performance | Mixed | Grade D | Crossover RCT · n = 12 · 2021 Healthy young men Form: 8% trehalose drink versus 8% glucose or water · Dose: 500 mL of 8% solution (40 g) during exercise · Duration: Single session Adrenaline was lower after trehalose than water in late exercise; the authors report it helped maintain performance. | 33923235 (opens PubMed)Source [4] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Trehalose powder (food-grade sweetener) | Varies[3] | Hydrolysed in the small intestine by trehalase; 25 g gave a slower, lower glucose and insulin rise than glucose.[3] | 3.3–10 g/day for 12 weeks raised no safety signals in sponsor trials; 100 g/day for 6 months was well tolerated in a small ataxia trial. People with low trehalase activity can get diarrhoea and gas after a 25 g load.[1][2][6][11] | Blood-sugar, fracture, exercise and ataxia trials |
Studied doses
Doses studied in human trials ranged from 3.3 g/day (about one teaspoon, 12 weeks) and 10 g/day (12 weeks) in blood-sugar and fracture studies to 100 g/day for 6 months in spinocerebellar ataxia.[1][2][9][6]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Medicines
- Diabetes medicinesPK studyTrehalose is digested to glucose, so it adds carbohydrate, though 25 g raised glucose and insulin less sharply than glucose. Effects alongside diabetes drugs have not been studied.[3]
Who should be careful
- Recent C. difficile infection or high risk of it
- Lab and mouse work showed epidemic C. difficile strains thrive on trehalose; a 2021 review found no proven link in people, but the question is not fully settled.[7][8]
- Trehalase deficiency or sensitive digestion
- In a 25 g trehalose load test, 19 of 64 people had clear abdominal symptoms; low trehalase activity lets trehalose reach the colon, causing loose stools and gas much like lactose intolerance.[11]
- People with diabetes
- It is still a sugar that breaks down into glucose; carbohydrate counts and glucose-lowering doses may need review.[3]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
Cost per studied dose, without the sales pitch
Compare any product you already have by the amount it delivers, not by capsule count or front-of-pack weight.
Cost per studied dose
Enter the price, servings and the amount per serving from your label.
Frequently asked questions
What is trehalose?
A natural, widely distributed sugar made of two glucose units, split into glucose by the gut enzyme trehalase.[1][3]
Does trehalose lower blood sugar?
It raises blood sugar more slowly than glucose. Sponsor trials found modest improvements in 2-hour glucose tolerance versus sucrose, mostly in subgroups.[1][2][3]
Does trehalose help ALS or other brain diseases?
Not so far. Weekly intravenous trehalose did not convincingly slow ALS, and an oral trial in spinocerebellar ataxia found no effect on ataxia.[5][6]
Sources
- [1]Daily consumption of one teaspoon of trehalose can help maintain glucose homeostasis: a double-blind, randomized controlled trial conducted in healthy volunteers.. Nutr J, 2020. RCT
- [2]Daily Intake of Trehalose Is Effective in the Prevention of Lifestyle-Related Diseases in Individuals with Risk Factors for Metabolic Syndrome.. J Nutr Sci Vitaminol (Tokyo), 2016. RCT
- [3]Glycemic, insulinemic and incretin responses after oral trehalose ingestion in healthy subjects.. Nutr J, 2017. crossover-RCT
- [4]Single Ingestion of Trehalose Enhances Prolonged Exercise Performance by Effective Use of Glucose and Lipid in Healthy Men.. Nutrients, 2021. crossover-RCT
- [5]Safety and efficacy of trehalose in amyotrophic lateral sclerosis (HEALEY ALS Platform Trial): an adaptive, phase 2/3, double-blind, randomised, placebo-controlled trial.. Lancet Neurol, 2025. RCT
- [6]Randomized double-blind placebo-controlled trial of the effects of oral trehalose in spinocerebellar ataxia type 3: An interim analysis.. Parkinsonism Relat Disord, 2024. RCT
- [7]Dietary trehalose enhances virulence of epidemic Clostridium difficile.. Nature, 2018. animal-study
- [8]Is there a causal relationship between trehalose consumption and Clostridioides difficile infection?. Curr Opin Gastroenterol, 2021. review
- [9]Effects of trehalose supplementation on bone healing, physical function, and pain in patients with pertrochanteric fractures: a randomized controlled trial.. Sci Rep, 2026. RCT
- [10]Disaccharide trehalose in experimental therapies for neurodegenerative disorders: Molecular targets and translational potential.. Pharmacol Res, 2022. review
- [11]Low trehalase activity is associated with abdominal symptoms caused by edible mushrooms.. Scand J Gastroenterol, 1999. observational
What changed
- Independent adversarial review: summary no longer says the sponsor trials beat sucrose (gains were versus baseline or in subgroups only); added missing safety item: trehalose intolerance from low trehalase activity (25 g load test, 19 of 64 symptomatic); ALS row discloses Seelos supplied the drug; exercise study names its Hayashibara co-author.
- Second-pass self-review: every PMID re-checked against NCBI esummary (title, year, no retraction or expression-of-concern flag), every dose, n and duration re-read against the PubMed abstract or PMC full text, grades held conservative, and interactions limited to what a cited source supports.
- First draft. Source titles and years taken from NCBI E-utilities esummary; abstracts read for every evidence row.