Quick answer
Ask your pharmacist or doctor before combining. Methotrexate works against folate, and its label treats two kinds of use differently: for cancer, take folic acid products only if your doctor directs it; for rheumatoid arthritis, psoriasis and polyarticular juvenile idiopathic arthritis, the label tells prescribers to give folic acid or folinic acid to reduce side effects.1,2
Key facts
- Methotrexate blocks dihydrofolate reductase, the enzyme cells need to put folate to use.1,2
- NIH says people taking methotrexate for cancer should consult their oncologist before taking folate supplements.2
- MedlinePlus says your doctor will probably prescribe folic acid with methotrexate to decrease some of its side effects.3
- Folic acid is found in multivitamins, prenatal vitamins and B-complex supplements, and is added to enriched grains in the US.4
Ask your pharmacist or doctor first
Folate supplements could interfere with methotrexate when it is used for cancer, and the methotrexate label says to take products containing folic acid then only if a doctor directs it. When methotrexate is used for rheumatoid arthritis, psoriasis or polyarticular juvenile idiopathic arthritis, the same label tells prescribers to give folic acid or folinic acid to reduce side effects.1,2,3,4
On the medicine's label
What is documented
On the medicine's label: the methotrexate tablet label has a section on folic acid. For cancers, it warns that products containing folic acid or its derivatives may decrease methotrexate's effectiveness and says to take them only as directed. For other conditions, it warns that folate deficiency may increase methotrexate's side effects and tells prescribers to give folic acid or folinic acid.1
From NIH: its folate fact sheets say folate supplements could interfere with methotrexate taken for cancer, and might reduce the stomach and gut side effects of the low doses used for rheumatoid arthritis or psoriasis.2,4
Expected from how the two work: methotrexate blocks the enzyme that turns folates into their usable form and competes with folates to get into cells. Extra folate can therefore blunt the medicine, which matters most when the goal is to stop cancer cells from dividing.1
Two kinds of use, different advice
| If methotrexate is for | What the label says |
|---|---|
| Cancer | Take products with folic acid or folinic acid only if your healthcare provider directs it |
| Rheumatoid arthritis, psoriasis or polyarticular juvenile idiopathic arthritis | Prescribers are told to give folic acid or folinic acid to lower the risk of side effects |
Both rules come from the same label, so the answer depends on why you take methotrexate. Your prescriber decides whether you need folic acid or folinic acid, how much and on which days; this page does not give an amount.1
What studies found
Reported in studies: a Cochrane review of six trials in 624 adults taking weekly methotrexate for rheumatoid arthritis found that folic or folinic acid cut stomach side effects such as nausea by about a quarter and abnormal liver tests by about three quarters, and fewer people stopped methotrexate. The review found no significant change in how well methotrexate controlled the arthritis.5
Folic acid you might not notice
Folic acid turns up in multivitamins, prenatal vitamins and B-complex products, and in enriched bread, pasta, rice and many breakfast cereals. Tell your prescriber about every supplement you take, with the folic acid amount from each label.4
What to ask your pharmacist or doctor
- Is my methotrexate for cancer or for another condition, and what does that mean for folic acid?
- Should I take folic acid or folinic acid, how much, and on which days?
- Do I need to stop or change my multivitamin or prenatal vitamin?
- Does the folic acid in fortified foods matter for me?
- Should my folate level be checked?
Questions people ask
Can I take a multivitamin with methotrexate?
Ask first. Multivitamins commonly contain folic acid. The methotrexate label says to avoid folic acid products during treatment for cancer unless directed, and for other uses your prescriber may already be giving you folic acid and will want to count what you take.1,4
Why do people on methotrexate take folic acid?
For rheumatoid arthritis, psoriasis and similar uses, the label tells prescribers to give folic or folinic acid because folate deficiency may increase methotrexate's side effects. MedlinePlus describes it as a way to decrease some of those side effects.1,3
See what we make
Every product shows its whole label and what its lab report covers. The store opens soon.
Sources
- Methotrexate tablets: prescribing information (American Health Packaging). DailyMed, U.S. National Library of Medicine. Published October 6, 2026. Opened 2026-10-07.
- National Institutes of Health, Office of Dietary Supplements. Folate: Fact Sheet for Health Professionals. Updated November 30, 2022. Opened 2026-10-07.
- MedlinePlus. Methotrexate. U.S. National Library of Medicine. Last revised October 15, 2025. Opened 2026-10-07.
- National Institutes of Health, Office of Dietary Supplements. Folate: Fact Sheet for Consumers. Updated November 1, 2022. Opened 2026-10-07.
- Shea B, Swinden MV, Tanjong Ghogomu E, et al. Folic acid and folinic acid for reducing side effects in patients receiving methotrexate for rheumatoid arthritis. Cochrane Database Syst Rev. 2013;(5):CD000951. Opened 2026-10-07.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.