My comment probably won't be so popular, but here goes. This is a question that needs to be answered in terms of real science, not pseudo science. Some of the commentary here relies on what I would call philosophical or religious texts. I have no objection to either; I am a practicing Catholic, my religious beliefs are central to my motives in being here, as is true for others. But if you ask me about the physical or health effects of either sexual behaviors or sexual abstinence, I would consider a citation from Scripture, or Saint Thomas Aquinas, to be an odd choice as scientific evidence. Now, I am not a scientist, I doubt any of us are, but like all of us, I have the ability to think critically, working from what I do know. The body is a highly complex system that, if healthy, is quite resilient. So it seems to me that while decisions about having sex, or masturbating, or even having involuntary emissions, can have effects on mood and on conscience, I find it dubious to make claims that these things have profound physical effects. In any case, the burden of proof must be on those who make such claims, and these claims should be viewed with close scrutiny, not accepted credulously. Here's the thing: how do you isolate the effect on body from effect on mood and conscience? If I am in a down mood, after, say, having sex or ejaculating after fapping, my body is likely to be affected, for many reasons. But that doesn't mean there was a physical effect due to loss of semen. The body knows what is doing. At various points, the body will expel semen on its own. As noted above, it makes sense we can indirectly affect this. However, you young guys may not realize this, but there can come a point, either because of age or other reasons, when your body stops having involuntary emissions. I've been 144 days with no O. I've had a number of erotic dreams, but no emissions, alas. A younger me would have. It happens. My bottom line on this question is this. I think there can be beneficial effects from abstinence, but mainly psychological/emotional, and I think it has more to do with whether we are having a "bad" sexual experience v. a "good" one, with "good" and "bad" bound up with some combination of our values, as well as what is more emotionally satisfying, and more "connecting." Some of this is morals; some of this really could be science - for example, the way our sexuality has evolved (or been designed) to foster bonding in relationship to child bearing and child rearing. So I do not believe there is any great value in semen retention, per se. I'm doing it for two reasons: as part of a needed "reset" after years of unhealthy consumption of porn, and because I believe it would be immoral to "spill my seed" outside marriage. If I were married, I'd be delighted NOT to retain my seed, in good conscience. Is the abstinent me really better off, physically and emotionally, than I would be married and copulating, solely because I am retaining my semen? I have no way of knowing, but those claim retaining semen, all other things being equal, does make me better off, have the burden of proving it. And without pseudoscience. Look: when advocates of abstaining from masturbation and porn make extravagant claims, it brings discredit to our message. Let's not make claims that aren't reasonable.