Sex is a physically exhausting experience. If you’re a woman, falling asleep right after sex isn’t uncommon.
But what’s the reason for this? INSIDER talked to sex and relationship therapist Laurie Mintz, sex researcher and sex educator Debra Laino, and more to find out the scientific and psychological reasons women feel sleepy after sex.
1. The hormones
Women and men react differently to the hormones that occur during sexual arousal, and this translates into sleepiness after sex. For example, the male body produces prolactin in spades during orgasms, which suppresses dopamine, a stimulating neurotransmitter that makes you feel awake. It also releases oxytocin and vasopressin, which, together with melatonin, trigger your internal body clock to start the sleep cycle.
On the other hand, women’s nervous systems stay in a high state of arousal, even if they only have one orgasm. In addition, they don’t get the same release of oxytocin and vasopressin as men do after orgasm, which contributes to the wind-up feeling after sex.
But, unlike men, women’s hormone levels drop during masturbation, which has sedative-like properties that can make it easier to fall asleep, according to a study. Researchers believe this is because the action between the sheets releases seminal fluid, which contains a cocktail of hormones that cause relaxation and sleepiness, including prolactin, oxytocin, and vasopressin.
The study is not without its limitations, though. The sample size was small and the findings were only correlational, meaning the relationship between the hormones and sleepiness was not proven. The researchers could not explain why some people experience this reaction and others do not, but they suggest that it may have something to do with the individual’s emotional and social context.
Often, the reason why some people fall asleep after sex is because they are highly aroused. Desire is an incredibly intense feeling of “wanting to want,” or “being in the mood.” It’s what leads to those unmistakable signs that you are sexually aroused: your muscles tighten, your heart beat increases, and your skin may turn red. And if you’re lucky, you might even reach orgasm during sex.
Arousal can lead to sleepiness because of the release of oxytocin and prolactin that cause feelings of pleasure and relaxation, Mintz tells INSIDER. It also reduces levels of the stress hormone cortisol, which can help you sleep better.
But the answer might be a little more complicated than that. Some women who are aroused before sleep and then fall asleep after sex are actually sleeping because they feel safe with their partners, relaxed, and grounded in the world, Mintz says. Others might be aroused because they are stressed and need to have sex for a release, and they then get tired after ejaculating or having an orgasm.
The researchers behind the study found that the more a person was likely to fall asleep after sex, the greater their partner’s desire for post-coital cuddling and chatting. This was true regardless of whether the person was the first to nod off or not, and it suggests that falling asleep after sex is a non-conscious way for couples to signal their desire for emotional connection.
3. The lights
We all know that sex at nighttime can cause arousal, but it also causes sleepiness. When we’re feeling arousal, our brains signal our bodies to start producing the sleep hormone melatonin. This melatonin is activated by the darkness, which is why it’s so important to have your sex in a dark room.
So, if your partner is always dozing off right after you’re done kissing and cuddling, it might be because the combination of prolactin, oxytocin, and melatonin is one hell of a trifecta that can knock anyone out cold. But don’t be mad at him – it’s actually a good thing. A study by evolutionary psychologists at the University of Michigan and Albright College found that partners who fell asleep right after sex had stronger desires for post-coital cuddling and conversation.
So, the next time you have a hot session in the bedroom, try to keep the lights on for a while afterward. That way, you’ll be able to get all the benefits of sexual intimacy and sleep in one go! But if you’re still struggling to fall asleep, try taking a quick shower before getting into bed, or experimenting with less supine positions like doggy style or pressed up against the wall. These positions will make your body feel more relaxed and help you drift off to sleep quicker.
4. A comfortable bed
Despite the popular caricature of heterosexual monogamous intercourse as a man collapsing into pillows after orgasm and his partner wide awake, twiddling her thumbs and staring at the ceiling (and let’s be real, that doesn’t actually happen in most homes), there are a lot of reasons a person might fall asleep after sex. We talked to experts in the field, including sex therapist and University of Florida psychology professor Dr. Laurie Mintz, clinical sexologist and certified sexuality educator Dr. Debra Laino, and sex therapist Dr. Carlen Costa, to learn why people sleep after sex.
They all agreed that sex is a powerful sedative and the action between the sheets is one of the best ways to catch some Zzzz’s. They also noted that a person’s desire for post-coital cuddles and pillow talk may be linked to their biological response to orgasm, with those who experience an orgasm falling asleep faster than those who don’t.
However, Winter notes that it’s important not to let the desire for a good night’s rest curtail commitment conversations and bonding with your partner after intimacy. Instead, he recommends staying up a little later to condense your sleep time. You can also make your bed extra comfy by eliminating the top sheet and replacing it with a duvet cover—the only function of a top sheet is to help keep you tucked in at night.