There isn’t sufficient evidence to confirm whether or not masturbation meaningfully affects immunity, but some preliminary research suggests there may be some positive effects.
One small 2004 study found men had a higher white blood cell count following orgasm from masturbation, compared to their white blood cell count before orgasm. White blood cells (also called leukocytes) are responsible for finding and attacking bacteria, viruses, parasites, etc., in the body. “These findings demonstrate that components of the innate immune system are activated by sexual arousal and orgasm,” the researchers state.
Tierney Lorenz, Ph.D., a clinical psychologist studying sexual health and immunity, says masturbation likely does affect immunity, though that may not mean what most people assume it does. “When people ask about immunity, they’re often talking about your susceptibility to illness, but the immune system actually does a lot of different things,” she tells mbg. “It helps your body recover from wounds, heal after exercise, and in the case of your period, helps it to tear down tissue that’s not being used and later build it back up.”
When it comes to sexual activity, including masturbation, the part of the immune system that’s mainly affected in women is related to reproduction. “The more someone engages in sexual activity and masturbation, the more they will be sending their body the message that reproduction is a priority, and the more the immune system will act in ways that align with that priority,” Lorenz explains. In some ways, that’s going to be to the person’s net benefit since reproductive mechanisms may reduce reactivity to certain autoimmune problems, she adds.