Listen, all women, don’t blame your man, you are also going to fall asleep immediately, if one day you can orgasm yourself like men. I would like to clarify that these particular hormones are not only released in man's brain, but also can be released in female brain after a real orgasm. But people have not found it yet. I agree that very much the brain play a very important role in ejaculation, not only in male orgasm, but also in female orgasm. In the process of ejaculation whatever male or female, the brain plays the same role.
There is another wrong point of view, because men dominate sexual life and consume a lot of physical strength, so they are tired and falling asleep immediately after ejaculation. I deny this view. This phenomenon about sleep after orgasm is an objective reality, a man will feel very sleepy, whether he ejaculates within 1 minute or 30 minutes. The time doesn’t matter, and you can think that Long-distance runners never fell asleep after the game. There must have something Specific released during orgasm which can reduce stress levels, which again could lead to relaxation and sleepiness.
Sleep after an orgasm is a normal phenomenon. Unfortunately, it is not completely clear so far.