Abstract: The present invention relates to the use of spinosyns and spinosyn compositions as pharmaceuticals and methods for treatment—including prevention—of protozoan infections and/or disorders relating to a protozoan infection, such as malaria and leishmania, viral infections such as Herpes Simplex virus and Influenza virus and neoplastic disorders or cancer. Advantageously, compositions of the invention inhibit protozoan, virus growth and neoplastic cell proliferation with only minimal or no disruption or ham to the host which may be an animal or human.