The Physiological Changes That Happen in Your Body When You Sleep With Someone New

The Physiological Changes That Happen in Your Body When You Sleep With Someone New

There's a lot of excitement that comes with sleeping with someone new: Your hands sweat, and your grasp of communication goes to hell in a horny handbasket. But your body has other responses that aren't quite as visible to the person who's seeing you naked. Studies show definite changes when you're with a new partner, whether it's romantic infatuation or something that involves candles and the Weeknd.

Love affects your limbic system and reward centers

When you're in a new relationship, it reduces stress and promotes good health. Your dopamine levels rise, your body's natural morphine levels increase and the attachment neurochemical, called oxytocin, spikes. According to a study in the journal Neuroendocrinology, love actually creates the physiological and neurological benefits of a single concept: wellness and the feeling of well-being.

"You may also experience spikes in levels of dopamine, serotonin and adrenaline with a new partner," Jess O'Reilly, author of The New Sex Bible and Astroglide's resident sex expert, told Mic. "The resulting mood changes can include feelings of excitement, euphoria and even a natural high."

A study from the journal Neuroscience found that animals choosing mates showed increases in oxytocin, the muscle contractor and blood pressure-raiser vasopressin and dopamine in the brain. 

Neuropeptides are for lovers

Research published in the journal Psychoneuroendocrinology studied 58 subjects; some had recently fallen in love, some were single and some were in long-term relationships.

The subjects who'd recently fallen in love showed higher levels of nerve growth factor, which contributes to keeping your body's systems steady and is full of seminal plasma, or sperm. This makes sense — when you're in a new relationship, your body is perpetually ready to get laid.

You get sweaty palms like a big galoot

Trying to stay calm can, ironically, make you nervous or anxious. So when you're flirting and have no idea if it's working, your amygdala — where your emotions and emotional behavior live — kicks into gear.

What's funny about this particular brain structure is that your amygdala controls elements of both fear and sex. Like Nicole He recently proved with a Tinder-swiping robot, your palms soften to indicate sweat gland activity when you see someone you find attractive. Nervousness raises the stimulation of a sweat gland thanks to your sympathetic (fight or flight) nervous system — but the same reaction occurs, at least physiologically, when you orgasm

"We see activation in the amygdala, which increases heart rate and blood pressure and sweating," neuroscientist Barry Komisaruk told Mic in October. It doesn't even have to be the cartoonishly heavy sweat associated with sex. 

But! Performance anxiety, and even pain, can kick back in

Not everyone has performance anxiety, or the brain's rude-as-hell tendency to flounder and kill your flow in the bedroom, but it's more common than you think.

In a study of 600 college students, women were half as likely to orgasm from oral sex or intercourse during a casual hookup than when in a serious relationship. The researchers said it probably stems from women feeling uncomfortable telling their hook-ups what they want during sex — and guys are often less focused on giving them what they want, anyway.

"You may experience performance pressure that results in inhibitions in the sexual response cycle, [like] vaginal pain, spasms or erectile dysfunction," O'Reilly told Mic, adding that vaginismus, or spasmodic pain in the vagina, "may be related to anxiety which can increase with new partners and may decrease in a long-term relationship."

In fact, a study from the Journal of Sexual Medicine showed that the women with vaginismus had higher levels of anxiety and neuroticism and lower levels of extraversion than the control group.

Sex with a new partner can be both fun and intimidating — and hopefully not just the latter. But in any case, if you're trying to make the experience great, here's something physiology, biology and neurology won't tell you to do: Ask questions and figure out what the other person likes. Don't just mash buttons and hope for the best.