Raw research findings for this medication. Mostly single studies, not curated or confirmed robust.
Leucovorin (folinic acid) is a ready-to-use form of folate that does not need the enzyme methotrexate blocks. It is given to rescue healthy cells after high-dose methotrexate, and, in a different role, alongside fluorouracil (as in FOLFOX and FOLFIRI), where it makes fluorouracil bind its target more tightly and work better. It also treats some folate deficiencies.
Leucovorin is converted into active folates in the body. The gene studies listing it were nearly all done in people receiving fluorouracil-based combinations, and looked at folate genes (MTHFR, TYMS), DNA repair genes and transporters for response and side effects; the findings mostly concern the combination rather than leucovorin itself. There is no CPIC or DPWG guideline.
Every published finding on gene variants and Leucovorin. Upload your DNA file to see which of these rows apply to you.
PharmGKB weighs all studies of a variant and rates how strong the evidence is, from 1A (strongest) to 4.
MTHFR rs1801131: Level 3. Toxicity: Neoplasms. 11.
MTHFR rs1801131: Level 3. Efficacy: Neoplasms. 4.
ERCC2 rs13181: Level 3. Efficacy, Toxicity: Colorectal Neoplasms. 3.
MTHFR rs1801133: Level 3. Efficacy: Colonic Neoplasms. 3.
Studies of how well it worked in people carrying a variant.
Study findings and evidence levels: PharmGKB (CC BY-SA 4.0). Guidelines: CPIC and DPWG, as bundled in PharmCAT. Most studies were done mainly in people of European ancestry.
More drugs from the same category
Not a prescribing recommendation. This page is educational information about pharmacogenomic research and clinical guidelines - it is not medical or dosing advice, and not a prediction of how any medication will work for you. Never start, stop, or change a medication or dose based on it; talk to your doctor or pharmacist, who can order clinical-grade testing if appropriate.
Content updated September 2026.
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