Supplements and Methotrexate.
Methotrexate, sold under the brand names Maxtrex, Metoject, Nordimet, Zlatal, Trexall, Otrexup, Rasuvo, is a disease-modifying antirheumatic drug.
Methotrexate is a disease-modifying antirheumatic drug (DMARD). It is used at low doses (typically 15 to 25mg once weekly) for rheumatoid arthritis, psoriasis, and some inflammatory bowel indications. Higher doses are used for certain cancers. The dosing schedule is the most important safety point. Methotrexate is weekly, not daily. Daily dosing errors have caused fatalities. Folic acid 5mg taken on a different day reduces methotrexate side effects without blunting efficacy. This is NICE-endorsed and standard UK rheumatology practice. The interaction with NSAIDs is the one the BNF flags. Chronic NSAID use reduces methotrexate clearance and raises toxicity risk, particularly in patients with reduced renal function. Folate supplementation matters. Methylated folate at low daily doses is acceptable, but folate timing and form should be discussed with the rheumatology team. Alcohol intake is the other significant variable for hepatic safety. Pregnancy is contraindicated, with strict contraception requirements and a three to six month washout period before conception.
Below are the 3 documented pairs we have explicitly assessed against Methotrexate in the Distil database: 3 caution. The pairs cluster around 2 mechanisms: Antifolate antagonism and Immunosuppression caution. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not on this list is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by supplement, and the missing-item form at the bottom of the page routes any uncatalogued supplement into our next curation pass.
Documented interactions
Last reviewed 15 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.
Antifolate antagonism
Caution Does Folate interact with Methotrexate?
Whether folate is safe with methotrexate depends entirely on why the methotrexate is being taken, so do not change anything yourself. For rheumatoid arthritis, psoriasis or similar conditions, low weekly methotrexate is very often prescribed alongside folic acid on purpose: the folate reduces sickness, mouth ulcers and liver-enzyme problems without stopping the methotrexate from working, and it is usually taken on a different day from the methotrexate. The picture is different for high-dose methotrexate used in cancer treatment, where folate and a related rescue drug are timed precisely by the cancer team and you should never add or adjust folate around it. If you take methotrexate, let whoever prescribes it set your folate, rather than starting or stopping it on your own.
Evidence: Supported by human study data.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Immunosuppression caution
Caution Does Bifidobacterium longum 1714 interact with Methotrexate?
If you take methotrexate, it is sensible to check with your specialist before starting this strain: methotrexate dampens the immune system, and in people whose defences are significantly weakened there have been rare cases of a probiotic organism getting into the bloodstream and causing an infection. At the usual low weekly doses for arthritis or psoriasis this risk is small. If you are seriously unwell in hospital or have a central line (a long-term drip line into a large vein, such as a PICC), start any probiotic, this strain included, only if the team caring for you agrees. Bifidobacterium longum 1714 is a live bacterium, and the evidence that probiotics are safe for most people comes from studies of people who were not significantly immunosuppressed, so on methotrexate let your specialist's advice decide.
Evidence: Supported by human study data.
Caution Does Probiotics interact with Methotrexate?
If you take methotrexate, it is sensible to check with your specialist before starting a probiotic: methotrexate dampens the immune system, and in people whose defences are significantly weakened there have been rare cases of the probiotic organism getting into the bloodstream and causing an infection. At the usual low weekly doses for arthritis or psoriasis this risk is small. If you do take one, choose a bacterial probiotic rather than a yeast-based one such as Saccharomyces boulardii, which European medicine labels rule out when the immune system is weakened. If you are seriously unwell in hospital or have a central line (a long-term drip line into a large vein, such as a PICC), start a probiotic only if the team caring for you agrees. Probiotics are live bacteria or yeast, and the evidence that they are safe for most people comes from studies of people who were not significantly immunosuppressed, so on methotrexate let your specialist's advice decide.
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 (food-supplement interactions only; for drug-drug interactions, the BNF is authoritative). Use the checker below to surface any supplement, 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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