Valosin 8mg Injection is used to treat pain associated with smooth muscle spasms. It may be used in cases of dysmenorrhea (painful menstruation) and for reducing post-operative pain. This injection is also used to reduce the first stage of labor. Valosin 8mg Injection is given by your doctor or nurse. Let your doctor know about all other medications you are taking as some may affect, or be affected by this medicine.