Have you ever started a new contraceptive and suddenly felt like your vagina was behaving differently?
Maybe your discharge changed, the smell changed, your period became lighter, or you suddenly seemed to get one vaginal infection after another. So is it possible that contraception influences your vaginal microbiome, or is it just a coincidence?
The short answer is: possibly, but it depends on several factors.
First of all, your vagina has its own microbiome, a little ecosystem of bacteria, including bacteria that help keep your vagina healthy. In many women, one form of bacteria are dominant that help maintain an acidic vaginal environment, which makes it harder for potentially harmful bacteria to overgrow. When this balance is disturbed, for example through changes in the body or hormonal changes associated with (hormonal) contraception, you may be more susceptible to problems such as bacterial vaginosis (BV).
Some studies show that, particularly during the first few months of starting a new hormonal contraceptive, such as the hormonal pill or hormonal IUD, there can be a temporary increase in vaginal infections or BV, with rates increasing around six weeks after starting. Over time, this tends to decrease again. However, other changes that can come with starting a new contraceptive, such as changes in sexual behaviour or condom use, can also influence the vaginal microbiome and may therefore contribute to this temporary increase in infections and BV.
At the same time, the longer-term picture can look different. Not all hormonal contraceptives contain the same hormones, doses or delivery methods. In long-term studies, many hormonal contraceptives, such as the combined pill, have actually been associated with a vaginal environment that contains more protective bacteria and fewer bacteria associated with BV. Research has also found an overall lower risk of BV among long-term hormonal contraceptive users. In contrast, studies have found a higher risk of BV among users of the non-hormonal copper IUD, which has been associated with changes in the vaginal microbiome, including fewer protective bacteria.
Recent reviews emphasise that we still don't fully understand how each individual contraceptive method interacts with the vaginal microbiome.
So if your vaginal health seems a little different after starting contraception, it doesn't automatically mean that something is wrong. Your vaginal environment is dynamic, and it can take some time to adjust to hormonal and other changes.
There isn't one contraceptive method that is universally “best” for your vaginal microbiome.
Research is still evolving and other factors, such as sexual behaviour, also influence your vaginal microbiome. What we do know is that the relationship between contraception and the vaginal microbiome depends on the method, and the individual.
If you notice persistent changes in discharge, a strong or unusual smell, itching, burning or discomfort, it's a good idea to get tested. BV, STIs, and other type of infections can have overlapping symptoms, so testing is often more useful and accurate than trying to diagnose the cause yourself.
