Masturbation is healthy and can help you learn more about what makes you feel sexually satisfied. But it won't affect your penis size, one way or the other. Here's what you need to know. But what about masturbation? Does climaxing reduce testosterone levels? This is a more direct question, but still a valid one. Does climaxing cause an instant drop in your testosterone levels? Scientists have looked into this issue in both humans and animals for a clear answer.