A vasectomy is a highly effective, permanent form of contraception.
It works by dividing the vas deferens, the tubes that carry sperm from the testicles. After the procedure, semen is still produced, but it should no longer contain sperm once clearance has been confirmed by semen testing.
Vasectomy should be regarded as permanent. Although reversal may sometimes be possible, it is expensive, not guaranteed to work, and should not be relied on.