Beta-Glucan and medications.
Beta-Glucan is in the Distil supplement database, evidence Grade A. The page below lists every medication we have explicitly assessed it against.
Beta-glucan is a soluble fibre, with two distinct uses depending on its source. Oat beta-glucan at 3g a day has Grade A evidence for lowering LDL cholesterol, backed by a 28-trial meta-analysis from Whitehead in 2014 and an FDA-authorised health claim since 1997. Mushroom beta-glucan, at 100 to 900mg, has Grade B evidence for immune function through NK cell activation. Oat beta-glucan also has Grade B evidence, from a meta-analysis of 103 trial comparisons by Zurbau in 2021, for lowering the rise in blood sugar and insulin after a carbohydrate-containing meal. That one is worth reading precisely: it has to be eaten with the meal to do anything, the effect is larger with higher-molecular-weight material, and it is a smaller rise after eating rather than a lower long-term blood sugar. Nothing here measures HbA1c, weight, or whether anyone goes on to develop diabetes. The mechanism is gut-based, which is also where the most important interaction lies. As a soluble fibre, beta-glucan can bind oral medicines in the gut and reduce how much is absorbed, the same documented class effect seen with psyllium. On any oral medication, including statins, levothyroxine, digoxin, oral antibiotics or DOACs, it should be taken at least two hours before or after the drug. With a statin, the gap is a precaution: the one study we hold on it, in mice, found oat bran taken with a low-dose statin made the cholesterol fall smaller, and we hold no study in people. Separate it from iron and zinc too, and tell your prescriber so lipid results are read in context.
Below are the 11 documented pairs we have explicitly assessed for Beta-Glucan: 6 caution and 5 good to know. The pairs cluster around 3 mechanisms: Additive glucose lowering, Immune-stimulant vs immunosuppressant (precautionary), and Additive lipid lowering. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication into our next curation pass.
Documented interactions
Last reviewed 14 June 2026. Each interaction below lists the evidence its assessment drew on: some rest on studies of the exact pair, others on mechanism evidence, where a citation may support one part of the reasoning rather than the exact combination. The evidence line on each entry says which.
Additive glucose lowering
Caution Does Beta-Glucan interact with Gliclazide?
Oat beta-glucan slows the rise in blood sugar after meals and can modestly lower blood sugar over time. Gliclazide is the diabetes tablet most likely to push blood sugar too low, so adding regular beta-glucan may add to that effect. If you start taking it regularly, check your glucose more often for the first few weeks and tell your GP, who may want to review your gliclazide dose.
Evidence: Supported by human study data.
Caution Does Beta-Glucan interact with Glimepiride?
Oat beta-glucan slows the rise in blood sugar after meals and can modestly lower blood sugar over time. Glimepiride is a sulfonylurea that can cause low blood sugar, so adding regular beta-glucan may add to that effect. If you start taking it regularly, monitor your glucose for the first few weeks and tell your GP, who may want to review your glimepiride dose.
Evidence: Limited human data, from small studies or case reports.
Caution Does Beta-Glucan interact with Insulin glargine?
Oat beta-glucan slows the rise in blood sugar after meals and can modestly lower blood sugar over time. Insulin already lowers blood sugar, so adding regular beta-glucan can add to its effect and increase the chance of a low. If you start taking it regularly, monitor your glucose more closely across the day and speak to your diabetes team, who may need to adjust your insulin dose.
Evidence: Supported by human study data.
Caution Does Beta-Glucan interact with Metformin?
Oat beta-glucan modestly lowers blood sugar on its own, so taking it with metformin adds a little to metformin's effect. Metformin rarely causes low blood sugar by itself, so the practical risk is small, but it is worth keeping an eye on your glucose when you first add regular beta-glucan.
Evidence: Limited human data, from small studies or case reports.
Immune-stimulant vs immunosuppressant (precautionary)
Caution Does Beta-Glucan interact with Ciclosporin?
Ciclosporin works by calming the immune system down, which is what stops your body rejecting a transplant or quietens an autoimmune condition. Beta-glucan from mushrooms or yeast does the opposite and gently stimulates the immune system. There is no proof the two clash in people, but because the stakes with a transplant or autoimmune disease are high, it is safer not to start beta-glucan while you take ciclosporin without first talking to your transplant or specialist team.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Beta-Glucan interact with Tacrolimus?
Tacrolimus works by calming the immune system down, which is what stops your body rejecting a transplant or quietens an autoimmune condition. Beta-glucan from mushrooms or yeast does the opposite and gently stimulates the immune system. There is no proof the two clash in people, but because the stakes with a transplant or autoimmune disease are high, it is safer not to start beta-glucan while you take tacrolimus without first talking to your transplant or specialist team.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Additive lipid lowering
Good to know Does Beta-Glucan interact with Atorvastatin?
Oat beta-glucan lowers LDL cholesterol by trapping bile acids in the gut, a different route from how a statin works. Taking the two together is complementary, not a harmful clash, and the small extra cholesterol reduction is a benefit. We treat this pair as safe to combine.
Evidence: Supported by human study data.
Good to know Does Beta-Glucan interact with Ezetimibe?
Oat beta-glucan lowers LDL cholesterol by trapping bile acids in the gut. Ezetimibe lowers cholesterol by a different route, by blocking cholesterol absorption in the small intestine. Taking the two together is complementary, not a harmful clash, and any extra cholesterol reduction is a benefit. We treat this pair as safe to combine.
Evidence: Supported by human study data.
Good to know Does Beta-Glucan interact with Pravastatin sodium?
Oat beta-glucan lowers LDL cholesterol by trapping bile acids in the gut, a different route from how a statin works. Taking the two together is complementary, not a harmful clash, and the small extra cholesterol reduction is a benefit. We treat this pair as safe to combine.
Evidence: Supported by human study data.
Good to know Does Beta-Glucan interact with Rosuvastatin calcium?
Oat beta-glucan lowers LDL cholesterol by trapping bile acids in the gut, a different route from how a statin works. Taking the two together is complementary, not a harmful clash, and the small extra cholesterol reduction is a benefit. We treat this pair as safe to combine.
Evidence: Supported by human study data.
Good to know Does Beta-Glucan interact with Simvastatin?
Oat beta-glucan lowers LDL cholesterol by trapping bile acids in the gut, a different route from how a statin works. Taking the two together is complementary, not a harmful clash, and the small extra cholesterol reduction is a benefit. We treat this pair as safe to combine.
Evidence: Supported by human study data.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope. Use the checker below to surface any medication, and submit a missing item if you take something we have not catalogued.
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How the checker decides
Every result has a source
Each pair we have assessed is cited to a published study (PMID) or the British National Formulary, so you can read the source yourself.
Four kinds of answer
Severe, caution, no known interaction, and not yet assessed. A pair we have not assessed is never shown as clear.
- Severe
- Caution
- No known interaction
- Not yet assessed
Nothing in our data is not a clearance
When nothing in our data records a problem with a pair, the result says no known interaction at typical doses, which is not a clearance: your pharmacist or GP can check the pair against your full medical history.
A full supplement review, built around you, not a generic stack.
The free checker answers one interaction question at a time. A Distil report reviews the bigger picture: your goals, diet, medications, current supplements and any blood results you provide, then shows what appears worth keeping, changing, adding or leaving out.
- what your diet already covers, so you are not adding a capsule for something food is already handling
- which evidence-graded compounds are worth considering for your goals, and which were considered but left out
- what to keep, change or stop from what you already take, plus the order to introduce anything new
- how your medications and complete supplement stack fit together, with daily timing and a clear point for reassessment
The interaction check is one section of the full report. You also get the reasoning behind each recommendation and the evidence references used.
£49 until 30 June 2027 · £79 from 1 July 2027.
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