Can SSRIs Impact Your Menstrual Cycle? Here's What We Know

Menstrual cycles can be finicky, no doubt about it. Although those who menstruate are told that a regular cycle is 28 days long, according to findings by the National Institutes of Health, 14% to 25% have irregular periods. Reasons for irregularity vary — Sometimes it's due to things like stress, emotional and physical changes, weight loss or weight gain, and similar things that come up in life. Other times, the irregularity can be linked to internal issues like PCOS or endometriosis. Although it's not always easy to pinpoint exactly what might be impacting your menstrual cycle, if you take any kind of selective serotonin reuptake inhibitor (SSRI) for depression, anxiety, or other psychological disorders, then they just might be the culprit.

A 2012 study published in Elsevier found that 24.6% of those who took antidepressants had irregular periods, whereas those who weren't taking SSRIs had far fewer menstrual disruptions at 12.2%. According to the study, the SSRIs with the greatest impact are paroxetine (Paxil), venlafaxine (Effexor XR), and sertraline (Zoloft), especially when combined with mirtazapine (Remeron). But of course, these aren't the only ones. 

Whether you're on SSRIs now, have been in the past, or are talking to your doctor about including them in your mental health routine, here's how they can impact your menstrual cycle. But don't worry, not all of the side effects on menstrual cycles are negative.

Although missing periods could be from things like pregnancy and stress (stress plays a major role in your menstrual cycle), if you've recently been prescribed SSRIs, your cycle could get a little wacky during the first three months of taking them. For some, this could mean missing periods —also known as secondary amenorrhea. Naturally, not everyone will experience this when they start taking antidepressants, but it is a possible side effect that you should know about.

The good thing is that, after you've been off the SSRIs for three months or so, your periods should get relatively back to normal. If your period stays MIA or is still all over the place after these first few months, then you should talk to your doctor. Because not all SSRIs mess with your menstrual cycle, there may be a better option for you. However, if you already have irregular periods, even after the three-month mark, the irregularity is likely to continue because you already had a disposition.

While cramps are part of the menstruation package for many people, SSRIs can make those cramps worse or even cause cramps in those who didn't have them before. SSRIs can also contribute to extra heavy bleeding during menstruation, which is related to this cramping. 

A 2004 study published in BMJ found that antidepressants can increase the risk of heavy and abnormal bleeding in those who take them. While the study covered all types of excessive bleeding, uterine bleeding was among them. When the uterus contracts to shed its lining during menstruation, this is the reason for cramps. So where there's more blood due to the effects of SSRIs, there will be more cramps to follow. If the bleeding and cramping become so severe that they're interfering with your life, make an appointment with your doctor. It might not necessarily be the SSRIs, but something more serious. 

What's interesting about SSRIs and their impact on menstrual cycles is that it's not always a bad thing. According to a 2022 study published in StatPearls, 80% to 90% of menstruating people experience at least one symptom of PMS. Of those who have PMS, 2.5% to 3% suffer from premenstrual dysphoric disorder (PMDD), which can feel like an extreme version of PMS that can interfere with normal activities to the point where functioning becomes a challenge.

"You may go from feeling like your usual self and then feeling like you're coming out of your skin, uncomfortable, irritable, not able to function normally in social situations, at work and at home,"  said Crystal Edler Schiller, assistant professor of psychiatry at the University of North Carolina School of Medicine to The New York Times. "When it's at its most severe, it can be really debilitating."

It's in these cases that a health care professional may turn to antidepressants to keep the mental disorder stable before and after that menstruation part of the cycle. The most commonly prescribed SSRIs for this are Zoloft, Celexa, Lexapro, and Prozac, per Harvard Health Publishing. 

Taking any type of medication can have unexpected effects on your menstrual cycle, including OTC painkillers like aspirin and ibuprofen. Because of this, you should pay attention to your body and how it responds to different meds. Although depression can have an effect on the menstrual cycle itself, adding SSRIs to the mix could be good for your mental health, but not so great for your cycle. It comes down to working with your doctor and finding the best medication for you.