If you've ever had a moment of suddenly not finding your partner quite as attractive as normal—without being able to pinpoint why—science says you're probably not alone in that. Turns out, according to new research, it could all be related to changing hormones, and that if your partner is male, it's likely that they're picking up on your iffy vibes too. Oh.
"Hormones have an underappreciated effect on behavior," said study author Francesca Righetti, an associate professor at VU Amsterdam. "This is true for men and women, just as it's true for animals of other species."
As part of her team's research, 33 women offered up urine samples for 15 days (in order to measure changes in oestradiol, progesterone, and testosterone levels). They and their male partners also filled in daily surveys centered on relationship satisfaction and how they perceived their partner. None of the women involved were using any form of hormonal contraception and all the couples had been together for at least four months.
The results found that both parties saw their relationship in a more negative light on the days that the female's oestradiol levels spiked (typically this happens just before ovulation). The women also found their partners less attractive during this time.
"Women's hormone levels change across their ovulatory cycles, and these changes are likely to affect their psychology, [including] the way they feel towards their romantic partner, " Francesca explained to PsyPost. "We found that the hormone oestradiol was associated with more negative partner evaluation."
This change in hormones was also observed by the men involved too, who reported lower well-being and a general vibe of knowing that their partner was less satisfied during this time.
Funnily enough though, despite these changes, the amount of sex the couples had didn't alter. "Changes in naturally varying hormones aren't going to turn a bad relationship into a good one, or a good relationship into a bad one," says Francesca. "But they might influence some subtle changes—like adding some minor turbulence to what is a great relationship on the whole, or temporarily making things a little nicer for a relationship that is pretty rocky."
It's also worth noting the sample size involved here is pretty small.
Anyway, if you ever suddenly find yourself feeling low-key repulsed by a boyfriend, but not knowing why, this could be your answer.