Inulin (inulin-type fructans)
Summary
Inulin and related fructans are prebiotic fibres from chicory root. In chronic constipation, five small trials found more frequent, softer stools, but no less pain or bloating. A 55-trial review found small falls in LDL cholesterol, triglycerides and weight (about 1 kg), with low-certainty evidence. Gas and bloating are common; 10 g a day was tolerated in one study.
Key facts
- Inulin-type fructans are the leading prebiotic fibres; oligofructose (FOS) is the shorter-chain form[2][3]
- 5 trials (252 people): more frequent and softer stools and faster transit; pain and bloating did not improve[1]
- 55 trials (2,518 adults): LDL −0.14 mmol/L, triglycerides −0.06 mmol/L and weight −0.97 kg; low to very low certainty[2]
- Up to 10 g/day of native inulin and 5 g/day of oligofructose were well tolerated; 10 g of oligofructose clearly raised gas and bloating[3]
- 2 graded human outcomes on this page
- October 11, 2026
How it works
ProposedInulin is a prebiotic fibre proposed to improve bowel function by influencing gut bacteria.[1]
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 |
|---|---|---|---|---|
| Cardiometabolic | Grade C | Improved | Meta-analysis of 55 trials · n = 2,518 · 2024 | 1 row |
| Constipation | Grade C | Improved | Meta-analysis of 5 trials · n = 252 · 2014 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| LDL cholesterol, triglycerides and body weight | Improved | Grade C | Meta-analysis · n = 2,518 · 2024 Adults in 55 randomized trials of at least 2 weeks Form: Inulin-type fructans · Dose: Varied across trials · Duration: At least 2 weeks LDL fell 0.14 mmol/L, triglycerides 0.06 mmol/L and weight 0.97 kg, with larger effects in trials of 6 weeks or more and in people with overweight; certainty was low to very low. | 38309832 (opens PubMed)Source [2] |
| Stool frequency and consistency in chronic constipation | Improved | Grade C | Meta-analysis · n = 252 · 2014 Adults with chronic constipation in 5 randomized trials Form: Inulin · Dose: Varied across trials · Duration: Varied across trials Stool frequency, consistency and transit time improved and hard stools were less likely (risk ratio 0.42); abdominal pain and bloating did not improve. | 25208775 (opens PubMed)Source [1] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Chicory inulin or inulin-FOS powder | Varies | No absorption data in the sources cited here; as a prebiotic it acts on gut bacteria.[1] | Up to 10 g/day of native inulin well tolerated; flatulence and bloating are the usual complaints.[3] | Constipation and cardiometabolic trials |
Studied doses
Doses studied in human trials ranged from 5 g to 10 g per dose in the tolerance study cited here; the pooled constipation and cardiometabolic trials used varied doses for 2 weeks or longer.[3][2]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- Irritable bowel or sensitive gut
- Fructans are fermentable and commonly cause gas and bloating; in constipation trials bloating did not improve.[3][1]
- Pregnancy and breastfeeding
- Supplement doses were not studied in these groups in the trials cited here.[2]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Where to buy Inulin (inulin-type fructans)
Products from brands we partner with that contain Inulin (inulin-type fructans). Listing a product is not a claim that it works; check the amount per serving against the doses studied above, and the label for other ingredients.
- SupersmartPaid linkFructo-Oligosaccharides (inulin-FOS)2 scoops: 10 g inulin-FOS from chicory root; 20 servings. That is the top of the range tolerated in the study cited here (10 g/day of native inulin; 10 g of short-chain oligofructose raised gas and bloating).Shop at Supersmart (opens in new tab)Price and label checked 2026-10-11 on the brand’s site.
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Frequently asked questions
Does inulin help constipation?
In 5 small trials it made stools more frequent and softer and sped transit, but did not ease pain or bloating.[1]
Does inulin lower cholesterol?
Slightly: about 0.14 mmol/L lower LDL across 38 trials, with very low certainty.[2]
Does inulin cause gas?
Often. Flatulence and bloating were the most common symptoms; 10 g of native inulin a day was tolerated.[3]
Is inulin the same as FOS?
Both are inulin-type fructans; oligofructose (FOS) has shorter chains and caused more symptoms at 10 g than native inulin.[3]
Sources
- [1]Effectiveness of inulin intake on indicators of chronic constipation; a meta-analysis of controlled randomized clinical trials. Nutr Hosp, 2014. meta-analysis
- [2]The effects of inulin-type fructans on cardiovascular disease risk factors: systematic review and meta-analysis of randomized controlled trials. Am J Clin Nutr, 2024. meta-analysis
- [3]Gastrointestinal tolerance of chicory inulin products. J Am Diet Assoc, 2010. crossover-RCT
What changed
- New monograph. Every PMID checked against NCBI E-utilities (title, journal and year from the PubMed record); each evidence row written from its abstract; intake and safety facts from the cited fact sheets.