system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why do orgasms make you sleepy? (In men)

Sometimes immediately after my orgasm, I just get a wave of sleepiness, absolutely tired.
gpt
Orgasm causes a release of things like endorphins, hormones? and neurotransmitters. Its a bit different for men and women. The substances released by men, specificly prolactin, tend to cause you to be very relaxed and can make you sleepy.