How Does Caffeine Affect Your Period?

by Haley Rosenberg

Caffeine has a pretty obvious effect on our bodies; otherwise, we wouldn’t give it so much daily responsibility to power us up. But could our morning helper actually be messing with our periods?

The answer is: Kind of

In a study of 403 participants, the individuals who drank more caffeine (300mg daily) were recorded to be twice as likely to have shorter menstrual cycles compared to people who didn’t drink coffee. Say what? Something I like to ingest daily can positively impact my life? That’s a first (move over, ice cream). The study stated that “The mechanism by which caffeine may alter the duration of the menstrual cycle is not clear, but such an effect could occur via the effect of caffeine on sex hormones or the hormone receptors.” A considered variable is that caffeine constricts the uterine blood vessels, thereby allowing less blood to escape and making bleeding days lighter or even less frequent.

However, never trust anything that sounds too good to be true. Though there is one positive side effect of caffeine intake on your period, most other side effects are pretty negative. Doctors often advise people to limit their intake rather than ramp it up. The constricting uterine blood vessels, along with the diuretic effects of caffeine, can mean that too much caffeine intake can make cramps more painful and prolonged.

Another thing to watch out for is how caffeine affects your hormones and moods. During your period, your hormone fluctuations can lead to mood swings, anxiety, and weepiness, and those are not symptoms that most people want to exacerbate. For example, an extra shot of espresso can be good for staying up late to finish a project, but it’s probably not the best when you’re experiencing PMS symptoms and increased irritability from your period. If you’re already feeling anxious and on edge, caffeine definitely will not help.

Another interesting way caffeine affects your cycle is by making your breasts more tender than usual on the days leading up to your period. Doctors say that they actually prescribe cutting caffeine intake in half for people who experience excess breast pain on their cycle.

Caffeine can also play a role in your period diarrhea. Many people experience digestive issues before or during their period, and coffee certainly doesn’t help! Hormones produced by the cells in your womb during your period cause cramps and can also leak into your bowels and stimulate diarrhea. Caffeine on its own is a stimulant that speeds up digestion and can cause diarrhea, so the two working together is a perfect storm of blowing up in the bathroom at brunch.

So although caffeine doesn’t necessarily disrupt your menstrual cycle, it can greatly impact the symptoms you experience. Whether it be emotional or physical, caffeine can play a role in your period woes. And, if you can’t completely quit the cup, maybe consider limiting your intake during your period so you can alleviate some of your pesky symptoms.