Vasectomy- vas deferens is cut, preventing sperm from traveling to mix with semen. Will be "successful" after two separate semen samples are sperm free, after 3 months or 15-18 ejaculations
About 1/300 fail, after 2 negative sperm counts failure rate is 1/2000
Sometimes irreversible, infection, internal bleeding, painful lump may appear, intermittent scrotal pain possible