Ever had the most earth-shattering, world-altering, mind-boggling sex of your life only to roll over to find your partner already passed out? 

Same. And whether or not they meant to, it can leave you feeling quite crushed. 

“I think we know that the common trope is that when men fall asleep after sex it can feel quite frustrating, isolating and disappointing for their partner to just have them turn away after what was hopefully a very close, intimate experience,” Selina Nguyen, a relationship therapist and sexologist at the Good Vibes Clinic, tells Body+Soul. 

“It’s very common for partners, regardless of gender, that if a partner falls asleep to feel quite lonely and disheartened, even if it's unintentional.”

Well it turns out that men aren’t actually to blame. And as is the case with many of our body’s reactions, it comes down to a cocktail of neurotransmitters. 

The post-orgasmic state of mind

So much thought goes into what leads up to the Big O, that you could be excused for forgetting about that post-orgasmic state – but there’s more to it than meets the sleepy-eye. 

“After climaxing, we know that our brains release a whole cocktail of neurotransmitters and feel-good hormones like dopamine, oxytocin – aka the love hormone – prolactin and vasopressin,” explains Nguyen.

“It’s the combination of these chemicals that helps us feel relaxed and at ease, helps reduce our stress levels, and helps us feel closer to each other.”

However, as we come down from this great high, our bodies begin to slow too. 

“Our muscles relax, our heart rate comes down, our blood pressure comes down, and our parasympathetic nervous system is activated, so that means we're down regulating and going into our ‘rest and digest’ system,” the sexologist says. 

Throw in the fact that we tend to have sex at night time and in a bed, and you’re essentially telling the body and brain that it’s time for sleep.

The male evolution

While this happens in all bodies, research shows it's quite common for men to release a certain cocktail of these chemicals after they orgasm. In particular prolactin, which really encourages sleepiness, especially after sex. 

“Even comparing partnered sex to masturbation, male bodies tend to release something like four times more prolactin, which is the neurotransmitter that helps us go to sleep,” Nguyen says.

“There's something that partnered sex gives us that's so soothing that there's a need on, like, this physiological level for sleep and rest afterwards in comparison to solo sex.” 

But the sex therapist says it’s also got to do with evolution.

“I think the evolutionary purpose of it is that it forces men into rest and recovery,” she explains, which is important when men have a longer refractory period – the time between orgasming and when they’re ready to go again – than their female counterparts. 

“I think men tend to get sleepy so that they can prepare for their next experience,” Nguyen adds.  

Multi-orgasmic women 

While men may lose their battle against prolactin and are quickly off to the land of nod, women are blessed with being multi-orgasmic and often the ability to bounce right back. 

“Because there is less of a refractory period for women, they don't need that rest and recovery that men do,” Nguyen says. 

“Which is why men fall asleep and women have more of the oxytocin hormone that promotes cuddling and wanting to feel close and more connected to a partner on an emotional mental level.”

The importance of aftercare

So, with so much going on inside the human body, it’s vital that we take care of ourselves and each other after the sex act itself.

“That is why aftercare is so important, because it could avoid a lot of miscommunications and hurt feelings around bodies overriding our brains,” explains Nguyen.  

“And being clear about what we want or what we need in these situations can help bring us back down from what was such a high and intimate peak experience.”

Ways to look after one another include cuddling or having a shower together, or even just making a plan that if you fall asleep, you hold each other.  

Or, you can make contingency plans so you don’t nod off. 

“If you know that your partner tends to get quite sleepy afterwards, maybe leave more lights on,” suggests the sexologist. “Or only get into sex positions that keep you upright and moving and active. 

“Or have sex in places around the house where it's a bit more difficult to fall asleep, like the couch or the kitchen, or literally anywhere else than the bed.”