Bleomycin sulfate is a medication that belongs to the class of antineoplastic agents, which are used in the treatment of various types of cancers. It is a complex of glycopeptide antibiotics that are produced by the bacterium Streptomyces verticillus.

Bleomycin sulfate works by disrupting the DNA in cancer cells, causing them to die. It is primarily used in the treatment of Hodgkin's lymphoma, non-Hodgkin's lymphoma, testicular cancer, and squamous cell carcinoma. It can be given by injection into a vein, muscle, or under the skin.

Common side effects of bleomycin sulfate include fever, chills, fatigue, skin rash, and mouth sores. It can also cause more serious side effects such as lung damage, which can occur in up to 10% of patients receiving the drug.