Most of us know the pill drill: it uses the hormones you naturally release when you’re pregnant to fool your body into thinking a new roomie has moved into your uterus. Progesterones block ovulation while oestrogen, when used, alters the uterine lining so any rogue eggs don’t implant in the womb. Here’s the thing, though: while normally your hormones cycle throughout the month, on the pill they stay fairly stable and flat. And it’s this different profile that’s believed to drive the pill’s mind-blowing impact and a whole new area of intrigue for scientists.
Turns out, that innocuous-looking little tablet can change how we think. You picture the hormones in your pill taking care of things in the reproductive camp, but “they are also very potent neurosteroids, which means they can have multiple effects in the brain,” reveals Jayashri Kulkarni, Professor of Psychiatry at the Monash Alfred Psychiatry Research Centre at Monash University. “For example, oestrogen has a direct impact on serotonin, dopamine and noradrenaline, which are the key hormones involved in regulating mood, behaviour and other emotional aspects of life. Hormones also have an impact on the building and destruction of brain circuits, which affects the structure of the brain,” she explains.
Hard to swallow
If this is news, it’s because scientists have only recently started really looking at the psychological effects of the pill. “It’s like we’ve finally taken our blinkers off,” says psychologist Dr Sarah E Hill, author of new book How the Pill Changes Everything: Your Brain on Birth Control. “We may have been studying how women’s natural hormones affect the brain for several decades, but it’s like we all forgot that the pill actually changes those hormones – and then suddenly researchers had a big ‘face-palm’ moment.” Jane Bennett, a natural fertility educator and author of The Pill: Are You Sure It’s For You? has been talking about these effects with her clients for years and she’s thrilled the topic is finally getting scientific validation. “We have such an issue around the potential of unwanted pregnancy that we like to skip over many issues with the pill,” she says. “It’s definitely been either ignored or under-appreciated.” Mood changes are one thing: 39 per cent of women experience these on the pill, according to a survey by symptom-tracking app The Lowdown. But there are also more subtle – and surprising – ways you might think or behave differently if you weren’t beholden to that little tablet. Ready for your trip through the sliding doors?
Your bed buddy might be different
Reckon you chose your partner because of his GSOH, music taste or Louis Theroux looks (hey, no judgement)? Actually, it came down to his smell. If you aren’t on the pill, you’ll tend to go for blokes who give off a scent that indicates their immune system is different from yours. “This is because any children [you have] will benefit more from parents with dissimilar immune systems, as the combination results in an enhanced immune system,” says Professor Gurit Birnbaum from the Baruch Ivcher School of Psychology in Israel and author of a new study looking at how the pill affects attraction. However, women on the pill are more likely to pick men with a similar immune system. Theory goes, your body thinks you’re pregs already, so finding someone who’ll look after your impending offspring is way more of a priority. What’s more, past research suggests that if we come off the pill, we revert back to wanting those different smelling guys. “This can cause changes in relationship or sexual satisfaction,” Birnbaum acknowledges. “There is a link between women starting relationships on the pill, and then coming off it and divorce rates.” Before you freak out, know that simply being aware this might happen can really help couples deal with any feelings that crop up. “Use it as a chance to improve the relationship and rebond.”
You’d read the room better
Struggling to gauge the tone in that meeting with your boss? Your ability to read people’s faces and judge how they’re feeling is suppressed by about 10 per cent when you’re on the pill, according to a recent study by the University of Greifswald in Germany. “Emotional recognition is one of the higher functioning cognitive tasks,” explains Kulkarni. “Oestrogen is an important modifier in this thinking, so it’s not surprising that where oestrogen levels are lowered (as in women on the pill), responses may be impaired.” Either that, or your boss really is harder to read than 007.
You might be less jealous
Feel a pang when your bestie has a new work wife, or your SO double-taps Jess-from-the-coffee-shop’s Insta pics? Heed this: according to a study published in the journal Evolution and Human Behaviour, women on the pill tend to be more suspicious, jealous and possessive than those not taking it. A second study by the same team specifically linked this to oestrogen levels, particularly in higher-dose pills. It’s been speculated that the big O is involved in moderating emotions such as jealousy, but that somehow synthetic oestrogens disrupts this.
The world could seem sunnier
While the pill might trigger mood swings in some women, in others it dampens emotions, which in turn leads to fewer mood extremes and – if San Diego State University research is to be believed – better relationships. However, those watered-down emotions can take the edge off joy a bit. A 2017 study by the Karolinska Institute in Sweden discovered that women on the pill were generally less satisfied with life than those not taking it – everything was just a bit meh. It was this loss of vitality that actually triggered Hill to write her book. “I was on the pill for more than a decade, but when I came off it, I felt really different,” she says. “It was like I’d climbed out of a black-and-white drawing and into a colourful reality.” Why the pill might have this impact is only just being teased out, she adds. “But one thing we know is that oestrogen is involved with reward. We find everything in life more rewarding at points of the cycle when oestrogen levels are high – but the pill keeps them artificially low.” Another theory lies with cortisol – yep, the stress hormone – which is involved in identifying relevant things in our environment, such as “Bad-stressful things, like a bear chasing us, but also good-stressful things, like falling in love and meeting your new best friend,” explains Hill. “Cortisol plays a role in terms of earmarking these types of events as being meaningful. And we know from research that the birth control pill can cause cortisol levels to flatline. [So] women don’t experience the normal dynamic changes in levels ... which may play a role in them experiencing the world as being more ‘blah’. But the research on this is really new.”
So, what now?
Before you kick that packet to the kerb, keep in mind that not every woman is affected by the pill in the same way, and not every type triggers the same effects. The jealousy study, for example, showed clearly that dose and formulation matters: progesterone wasn’t associated with any change in green-eyed feelings, so those on the POP (or mini pill) wouldn’t experience the impact. In her work, Kulkarni has also found the pill Zoely, which contains a form of progesterone called nomegestrol, is mood neutral. And if you’re wondering whether all this means you should come off the pill entirely? “Oh God, no,” says Kulkarni. “The pill is a huge boon for women.” Hill agrees: “I still don’t think the research is anything to get alarmed about. Yes, it pinpoints important ways that the pill might affect the brain, but it doesn’t mean immediately coming off it. Being aware just makes good health sense, so see if you notice any effects and compare these to the potential benefits of the pill for you. Then you can decide if the trade-off is worth it, depending on where you are in your life and what your goals are,” she says.
What it comes down to, adds Kulkarni, is collaboration between women and experts. “It’s really critical that healthcare professionals understand that different pills have different effects on different women,” she says. “And if somebody comes into your [medical] practice and says, ‘This pill doesn’t work on me, or it’s making me feel depressed,’ that is real. The doctor and patient should sit together and work out [what to try next].” A dose of teamwork mixed with advocating for your own wellbeing? That’s a pill worth swallowing.