[3] It acts against neoplastic growth, and it inhibits the replication of Orthohepevirus A, the causative agent of Hepatitis E, through upregulation of interferon signaling.

[6] Common side effects include bone marrow suppression, liver and kidney problems, nausea, fever, rash, shortness of breath, mouth sores, diarrhea, neuropathy, and hair loss.

[15] Taking gemcitabine can also affect fertility in men and women, sex life, and menstruation.

[11][18] More than 10% of users develop adverse effects, including difficulty breathing, low white and red blood cells counts, low platelet counts, vomiting and nausea, elevated transaminases, rashes and itchy skin, hair loss, blood and protein in urine, flu-like symptoms, and edema.

[11][16] Common adverse effects (occurring in 1–10% of users) include fever, loss of appetite, headache, difficulty sleeping, tiredness, cough, runny nose, diarrhea, mouth and lip sores, sweating, back pain, and muscle pain.

[11] Thrombotic thrombocytopenic purpura (TTP) is a rare but serious side effect that been associated with particular chemotherapy medications including gemcitabine.

TTP is a blood disorder and can lead to microangipathic hemolytic anemia (MAHA), neurologic abnormalities, fever, and renal disease.

[20][22] After being thrice phosphorylated, gemcitabine can masquerade as deoxycytidine triphosphate and is incorporated into new DNA strands being synthesized as the cell replicates.

[3][20][21] The form of gemcitabine with two phosphates attached (dFdCDP) also has activity; it inhibits the enzyme ribonucleotide reductase (RNR), which is needed to create new DNA nucleotides.

Then, Reformatsky reaction under standard conditions will yield a 3:1 anti/syn diastereomeric mixture, with one major product.

It was intended as an antiviral drug, but preclinical testing showed that it killed leukemia cells in vitro.

[31] As of 2017, gemcitabine was marketed under many brand names worldwide: Abine, Accogem, Acytabin, Antoril, axigem, Bendacitabin, Biogem, Boligem, Celzar, Citegin, Cytigem, Cytogem, Daplax, DBL, Demozar, Dercin, Emcitab, Enekamub, Eriogem, Fotinex, Gebina, Gemalata, Gembin, Gembine, Gembio, Gemcel, Gemcetin, Gemcibine, Gemcikal, Gemcipen, Gemcired, Gemcirena, Gemcit, Gemcitabin, Gemcitabina, Gemcitabine, Gemcitabinum, Gemcitan, Gemedac, Gemflor, Gemful, Gemita, Gemko, Gemliquid, Gemmis, Gemnil, Gempower, Gemsol, Gemstad, Gemstada, Gemtabine, Gemtavis, Gemtaz, Gemtero, Gemtra, Gemtro, Gemvic, Gemxit, Gemzar, Gentabim, Genuten, Genvir, Geroam, Gestredos, Getanosan, Getmisi, Gezt, Gitrabin, Gramagen, Haxanit, Jemta, Kalbezar, Medigem, Meditabine, Nabigem, Nallian, Oncogem, Oncoril, Pamigeno, Ribozar, Santabin, Sitagem, Symtabin, Yu Jie, Ze Fei, and Zefei.