Why Some People Feel Tired After Sex

If you've ever had fantastic sex, the type of sex riddled in orgasms, there's a chance that afterward you might feel tired. Or, maybe you had one hell of an orgasm, and feel ready to go for another round — or three or four — instead. Honestly, it could go one way or the other. While there are those who feel totally wiped out after sex and ready for a nap, there are also those who feel like they're able to take on the world after sex.

"Not everyone feels tired after sex; some people do and others don't," Dr. Dawn Michael, certified clinical sexologist, sexuality counselor, and author of My Husband Won't Have Sex With Me, tells Bustle. "There are hormones that are released after an orgasm such as oxytocin and dopamine. Women tend to release more dopamine than men do and this can actually wake you rather then make you feel sleepy."

But for those who do feel like they need to go to sleep right after sex, there are a few reasons as to what this might be there case, from your brain pretty much shutting off after an orgasm to oxytocin's calming affect on your body.

1Your Brain May Shut Off

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"Many people fall asleep after sex and French researchers believe they have uncovered the reason behind this phenomenon," Dr. Jess O’Reilly, sexologist and host of the Sex With Dr Jess Podcast, tells Bustle. "The cerebral cortex shuts off during orgasm and the cingulate cortex and the amygdala send messages to other parts of the brain signaling the need to squash all sexual desire."

This is also why the French call orgasms "la petite mort," which literally translates to "the little death." If the brain shuts off, then nips all sexual desire in the bud, it makes sense that the need to sleep would follow.

2Sleep-Inducing Chemicals Kick Into High Gear

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Dr. O'Reilly says there's also a release of sleep-inducing chemicals after sex.

In fact, serotonin (which maintains normal sleep cycles), norepinephrine (which aids REM sleep), and vasopressin (which boosts sleep quality) are all released after orgasm, so it certainly makes sense why some may need to hit the hay ASAP.

3Oxytocin Takes Over

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In addition to the flood of those sleep chemicals, oxytocin, also known as the "cuddle hormone," which is released after orgasm, contributes to a relaxed, feel-good state.

"Oxytocin can make you feel calm and that can have a sleepy effect," says Dr. Michael.

4The Time Of Day Plays A Role

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"There are a few other factors," says Dr. Michael. "If you have sex in the morning you are less likely to fall asleep so the time of day has an impact on it as well."

If you've had a long day and have sex before bed, then you're definitely more likely to feel tired after sex than if you start the day off with morning sex. In fact, morning sex can really get you revved up and ready to tackle the world in a whole new way.

5Hormones Just Affect People Differently

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Ultimately, as Dr. Michael points out, sex may not make everyone tired. Basically, it depends on your hormones as to whether or not you feel sleepy after sex and just how sleepy you might feel.

But if you do feel tired after sex, now you know why. If you don't feel tired after sex and feel like you could probably run a marathon if you had to (I am one of those people) now you know why, too.