What happens to unejaculated semen?

Last updated on February 9, 2022



I have recently heard a preacher say that masturbation is a sin because it is sexual stimulation, and it doesn’t involve a partner and so the semen is wasted by pouring out on the ground, which he says that God hates that act of pouring out on the ground. A scientific reason he said was that the seminal vesicles, which hold semen, absorb the semen into the body after some time when not used. Therefore, he concludes that the act of masturbation is pure motivation for sexual stimulation outside and pre-marriage so by definition it is sin. Is that scientific reason really scientific? Does our body absorb the semen so that masturbation becomes pure sexual stimulation and sin for that reason?

Thank you.


I looked once again for an actual scientific study on what happens if semen is not ejaculated. Many people cite the fact that unused sperm is broken down and absorbed by the body. This is what happens when men have a vasectomy. However, men with vasectomies still produce semen and still ejaculate. Repeatedly I found people claiming that semen is reabsorbed but no one actually gives evidence that it is true. It appears to be a well-accepted myth. I actually have my doubts that it is true because men who have a blocked ejaculatory duct suffer pain which causes them to seek treatment.

There are three known ways that semen leaves the body:

  1. Masturbation triggers an ejaculation of semen.
  2. Wet dreams cause an ejaculation of semen for many men while they sleep.
  3. When seminal vesicles get too full, some of the excess semen drips out during arousal, which is then flushed out the next time a guy urinates.

I suspect that those who claim to not ejaculate are experiencing wet dreams and not noticing that semen came out or they produce semen slowly enough that the few drops with each arousal are enough to keep the semen backlog from getting too great. However, I know of no study that can prove this one way or another.

To claim that sexual stimulation of yourself is sinful, the preacher should have been able to provide some sort of passage proving his point. I know of none. I do know of some passages in the Old Testament that deal with ejaculations without a sexual partner. These ejaculations are treated in a similar way to a woman having a monthly blood flow. See Is masturbation considered a sin?

In regards to spilling semen on the ground, I assume the preacher is referring to the story of Onan in Genesis 38. Onan was not masturbating. He used the withdrawal method during sex to try and prevent getting his deceased brother’s wife (now his wife) pregnant. Yes, semen was spilled, but the sin was Onan’s greed. See