Anyone who has used hormonal contraception has most likely seen the long list of potential side effects. Next to the health warnings, 'change in sex drive' is easy to ignore. But for women who experience them, changes in libido can be frustrating and upsetting.
Each type of hormonal contraception can affect each individual differently. Sex drive is influenced by so many different factors that it can be difficult to tell whether it is contraception causing it to change.
"I've been asked before what proportion of women experience a decrease or reduction in sexual interest [when using hormonal contraception]. It's really hard to answer that," says Professor Cynthia Graham, editor-in-chief of the Journal of Sex Research and professor in sexual and reproductive health within Psychology at the University of Southampton.
"Some women will say it goes up; some women will say it goes markedly down. Many women say that they don't notice any change. I think the bulk of the evidence shows that a minority of women are significantly affected in terms of sexual interest. The clearest statement you can make about the main change is that it's variable."
Where's the research?
Despite there being over 44,000 research papers on oral contraceptives, fewer than 100 have looked at their impact on women's libido and sexuality. We have the testimonies of women who have experienced a change in libido whilst on hormonal contraception but there are very few studies to back up their claims.
"Compared to effects on mood which we know more about, we don't have the large-scale studies," says Graham.
A combination of funding, concerns about the subjectivity of sex drive and even elements of sexism all contribute to the lack of information on hormonal contraception and libido, she says.
"This is just too complex an area. But other things are difficult, and we don't shy away from studying them. [Some researchers and gynaecologists] do still have this view that we shouldn’t really ask women about this."
What we do know is that a loss of sex drive is a key factor in dissatisfaction with hormonal contraception, says Graham, as one of her studies at the Kinsey Institute found.
"The findings were really clear cut. What we found were the best predictors of women discontinuing or switching pills were emotional and sexual side effects."
The problem with many of the studies is that they are cross-sectional, according to Graham. They may compare current or past users of hormonal contraception to 'never-users'.
"Women who choose to take the pill compared to other methods are different in many ways. They're different in personality, often different in attitudes towards sexuality; they’re different in sexual behaviour."
'Not having to plan sex around a period was amazing'
Some women actually find that their sex drive increases whilst using hormonal contraception, especially if they experience improved mood or period symptoms as well.
For Heather, finding the right contraceptive to manage her painful and heavy periods involved trial and error. Now, knowing that she is protected against pregnancy and avoiding period symptoms gives her the peace of mind to enjoy sex. She first tried the contraceptive pill, with no side effects, before switching to the NuvaRing. "I felt more confident sexually with NuvaRing because I couldn't miss a pill."
Heather later decided to switch to an intrauterine system (IUS, or hormonal coil) called Mirena. "Mirena has been a dream," says Heather. "Within two months I didn't have a regular bleed anymore, and the most I had was some off and on spotting. My sex drive increased somewhat. Not having to plan sex around a period was amazing. By four months, my cramps were basically non-existent. Cramps and my period were definite mood killers. Having a super reliable form of birth control and my life back removed a lot of barriers to good sex."
Other factors including partners, stress and busy schedules have impacted Heather's sex drive at various points in her life, but using hormonal contraception takes away at least some of the worry holding back her sex life.
"I wouldn't trade my Mirena for anything," she says. "It gives me my body and my time back. It gives me the peace of mind I need to just react, have sex, and not worry. I just get to be sexual without any maintenance (well, for five years at a time). I feel the most like myself and least distracted."
Losing your libido
Alice Pelton is the founder of The Lowdown, the world's first contraception review website. It asks people who have used contraception to share their experience and any side effects, as well as how contraception impacted their weight, periods, mood and sex drive.
"Our review data so far indicates that most people feel that their contraception hasn't changed their sex drive (41%); however, this is closely followed by 37% of people feeling that their contraception is causing their sex drive to decrease. Only 9% report an increase in libido due to their contraception, and 12% can't tell," says Pelton.
The reviews from those who have experienced a loss of libido highlight the impact it can have on relationships and happiness. One woman reported that the contraceptive pill "caused me to completely lose my sex drive. I was extremely irritable and felt 'numb' most of the time. This had a huge effect on my relationship and, in the end, I made the decision to stop taking this pill."
Another user, prescribed the contraceptive pill for her adult acne, said that her "non-existent" sex drive was impacting her marriage and that she would "love to come off this pill but mentally I can't handle the acne at the moment". Other users didn't realise that their sex drive had changed until they stopped using their contraception.
According to Pelton's analysis of the reviews, "the reduction in sex drive seems to be highest among users of progestogen-only hormonal contraception - with 50% of progestogen pill users, 48% of implant and 47% of injection reviewers reporting a loss in sex drive.”
She cites a study by Graham which supports these findings. The research investigated the link between progestogen and lower levels of testosterone. There is evidence that low testosterone levels in women have been linked to reduced desire, arousal and number of orgasms. Sensitivity to testosterone and how it affects sex drive varies from woman to woman. They found that some, but not all, women who were using a progestogen pill experienced lower levels of testosterone and lower libido.
Not only could low libido be associated with hormone levels, but physical and emotional side effects of hormonal contraception can also reduce the desire to have sex, explains Pelton.
"Some women are also reporting that some of the physical side effects from contraception - vaginal dryness, irritation, spotting and irregular periods - are also having an impact on their sex drive, in the sense that these things don't help put them in the mood for sex."
You should speak with your healthcare professional about changing your contraception if it isn't working for you. No two women experience contraception in the same way. Knowing what is normal for you will help you to notice if anything changes.
Sex drive might not be your first worry when it comes to hormonal contraception, but changes to your libido aren't something you have to put up with either.