# Leucovorin (folinic acid)

Source: https://onco.cc/drugs/leucovorin/  
OnCo record `leucovorin` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Leucovorin is not a cancer drug in itself: it rescues normal tissue after high-dose methotrexate and, given with fluorouracil, makes that chemotherapy work better, which is why it appears in FOLFOX, FOLFIRI and FOLFIRINOX.

## Summary

Leucovorin (folinic acid, calcium folinate) is a form of folate that cells can use without the enzyme methotrexate blocks. Given after high-dose methotrexate it lets normal bone marrow and gut recover while the drug has already acted on the tumour; given with fluorouracil it increases the drug's binding to its target enzyme thymidylate synthase, an effect that underlies every fluorouracil-based bowel, stomach and pancreatic cancer regimen. Levoleucovorin is the active isomer alone at half the dose. It is a generic medicine on the WHO essential medicines list.

## Fields

- Kind: Treatment
- Status: established
- Last checked: 2026-09-08
- Also known as: Leucovorin Calcium; Folinic acid; Calcium folinate; Levoleucovorin (Fusilev, Khapzory)
- Tags: gap-fill; generic
- Brand: Wellcovorin / generic
- Modality: Reduced folate (rescue agent and chemotherapy modulator)
- Mechanism: A reduced folate that bypasses dihydrofolate reductase, rescuing normal cells from methotrexate, and that stabilises the fluorouracil-thymidylate synthase complex to make fluorouracil more effective.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Folinic_acid
- Label (DailyMed): https://dailymed.nlm.nih.gov/dailymed/search.cfm?labeltype=all&query=leucovorin%20calcium

## Connected records

- cancers: [Acute lymphoblastic leukaemia](https://onco.cc/cancers/all-leukemia/), [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Gastric & gastro-oesophageal junction cancer](https://onco.cc/cancers/gastric/), [Pancreatic ductal adenocarcinoma](https://onco.cc/cancers/pancreatic/)
- technologies: [Cytotoxic chemotherapy](https://onco.cc/technologies/cytotoxic-chemotherapy/)
- targets: [Dihydrofolate reductase (DHFR)](https://onco.cc/targets/dhfr/), [Thymidylate synthase (TYMS)](https://onco.cc/targets/tyms/)
- drugs: [Fluorouracil (5-FU)](https://onco.cc/drugs/fluorouracil/), [Methotrexate](https://onco.cc/drugs/methotrexate/)

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JSON: https://onco.cc/api/v1/entities/leucovorin.json