The research by Intrinsic Insight for online doctor Zava also found that as many as 3.3 million women in the UK have experienced side effects from taking the pill.
These include migraines, weight changes, irregular bleeding, acne, stomach problems, mental health issues and a loss of sex drive.
However, nearly a third of women who experience these side effects haven't told a medical professional, meaning they could be on a pill that's unsuitable for them without realising it.
Abigail, a 24-year-old woman from London, told Refinery29 that she feels unhappy with the pill she takes, but doesn't "feel like my doctor has acknowledged this".
"I’ve been on the pill on and off for seven years, and I’ve tried two different brands," she said. "I initially went on the pill to help with heavy periods, but the first brand made sex really painful and gave me bad mood swings, and although my GP told me to persevere I decided to listen to my own body and take a break.
"Now I’m trying a different brand of pill but I’m still not fully happy and think it might be making my anxiety worse. But again, I don’t feel like my doctor has acknowledged this. I don’t feel like I’ve been taken seriously when it comes to the side effects."
Abigail also said she feels "confused about the guidelines on how to take the pill," saying: "I was already taking back-to-back courses of my pill before they came out but I’d really appreciate some more advice on whether that’s okay for my body."
According to the latest guidelines from the Faculty of Sexual Health and Reproductive Healthcare (FSRH), there is no health benefit from taking the traditional seven-day break after a 21-day cycle of a combined hormonal contraception (CHC) pill.
The latest guidelines also state that women may actually reduce their risk of getting pregnant by taking back-to-back courses of CHS, or by shortening the seven-day break to just four days.
"We don’t need a regular monthly bleed to be healthy, and lots of women welcome the option of avoiding bleeding," Dr Sarah Hardman of the FSRH said in January.
However, Zava's research found that more than one in two women believe the monthly bleed is important – either to check you’re not pregnant, or because it’s good for your health, or to make the pill more effective.
Dr Louisa Draper, Medical Director at Zava said in response to the results: "It’s clear that women need access to more information when it comes to their contraception. It’s a confused picture, supported by our own patients who often come to us after repeatedly suffering from contraceptive pill side effects.
"The new guidelines give us the opportunity to start a renewed conversation about contraception. A woman’s contraception should suit her individual lifestyle and requirements, without a detrimental effect on her health.
"Whilst there are other methods of contraception available, the pill remains the most popular for British women, so if women want to take the pill, let’s make sure it’s the right one. At Zava we want to encourage conversation around which pill is best for each individual."