Vasectomy is a simple, safe procedure that makes a man sterile (unable to father a child). It is the most effective birth control method for men.
Your Reproductive System
For pregnancy to occur, a man’s sperm (male reproductive cells) must join with a woman’s egg. To understand how a vasectomy works, you need to know how sperm are produced, stored, and released by the body:
During the procedure, the 2 vas deferens are cut and sealed off. This prevents sperm from traveling from the testes to the penis. It is the only change in your reproductive system. The testes still produce sperm. But since the sperm have nowhere to go, they die and are absorbed by your body. Only a very small amount of semen is made up of sperm. So after a vasectomy, your semen won’t look or feel any different.
After a vasectomy, some active sperm still remain in the reproductive system. It will take about 3 months and numerous ejaculations before the semen is completely free of sperm. Until then, you’ll need to use another form of birth control.