Why are men sleepy after sex?
According to a study, it was found that the hormone prolactin is responsible for this action. It works by inhibiting dopamine, an excitatory neurotransmitter that makes you feel alert. Your body releases it in bursts when you lie.
On the other hand, oxytocin, the "feel good" hormone, is also increased during sex, helping to clear any stressful thoughts out of your mind and allowing you to relax and fall asleep easier afterward. . Also, when you have sex with the lights off, it signals your body's internal clock that it's time to go to sleep. When this happens, the hormone melatonin triggers your sleep cycle. This is the reason why you sleep right after sex, not any other speculation from people.