If a male loses both his testicles it's called castration. Because the man cannot produce sperm or testosterone, it has a big effect on the man's life. Because he cannot make sperm, he cannot have children. And because he cannot make the male hormone testosterone, he becomes less like a male. He may lose some of his muscles, and put on weight. A man who has lost his testicles may take testosterone medicine so that he does not have these changes. 