5,6-dihydro-5-Fluorouracil (5-FUH2) is an inactive metabolite of 5-FU and can be used for the study of organismal metabolism.

The combination of 5,6-dihydro-5-Fluorouracil (5-Fu) and NSC 123127 (Dox) demonstrates synergistic anticancer efficacy. The IC50 values for 5-Fu/Dox-DNM against human breast cancer (MDA-MB-231) cells are 0.25 μg/mL, with cytotoxicity increasing by 11.2-fold and 6.1-fold for Dox-DNM and 5-Fu-DNM, respectively [4]. In NFBD1-inhibited NPC cells treated with 5,6-dihydro-5-Fluorouracil (5-FU) and CDDP, lentivirus-mediated short hairpin RNA depletion of NFBD1 expression in NPC CNE1 cell line enhances sensitivity. Knockdown of NFBD1 significantly induces apoptosis in CNE1 cells treated with CDDP or 5,6-dihydro-5-Fluorouracil [2].

Administered at a dose of 23 mg/kg three times a week for 14 days, 5,6-dihydro-5-Fluorouracil(5-FU) induces gastrointestinal transit acceleration associated with acute intestinal inflammation starting on the third day of treatment. This may lead to sustained changes in the enteric nervous system (ENS) observed beyond the 7th day, and the 14-day treatment results in delayed gastrointestinal transit and colonic motility disorders [1].