Did you know that birth control pills may be impairing your ability to accurately read and relate to the emotions of other people?

Birth control pills are a popular hormone-based contraceptive used by 10 million American women and more than 100 million women worldwide, according to the National Center for Health Research. The more generally well-known physical side effects of these pills include weight gain, headaches, decreased sex drive, nausea, mood changes, spotting between periods, as well as the slightly-increased risk of breast and cervical cancer, blood clots and high blood pressure.

Recent research from Germany, however, has opened a whole new arena of potential psychological and behavioral side effects.

The study, “Oral Contraceptives Impair Complex Emotion Recognition in Healthy Women,” published earlier this month in the journal Frontiers in Neuroscience indicates that oral contraceptive users are nearly 10 percent less accurate at reading subtle emotions such as pride or contempt than other women. The ability to read more obvious emotions such as happiness or fear was not affected, according to the study.

So, why does this happen? According to Alexander Lischke, biological psychologist from the University of Greifswald in Germany, the female hormones estrogen and progesterone are known to influence brain regions involved with emotional recognition. Contraceptive pills work by suppressing these hormones.

Lischke added that researchers relied on a “very challenging emotion recognition test” that involved the decoding of complex emotional signals from the eye region of the face. This might explain why Lischke isn’t so convinced that the subtle emotional shifts are enough to warrant action. He stated, “if oral contraceptives caused dramatic impairments in women’s emotion recognition, we would have probably noticed this in our everyday interactions with our partners.”

Discussing Birth Control Risks With Gynecologist

This claim isn’t reason to write off the observed impacts, though.

Even subtle shifts in emotional receptivity might impact a woman’s capacity to interpret interactions with others. According to the study’s authors, being able to understand emotional expression is essential for forming and maintaining relationships, especially intimate partnerships.

Inaccurate emotional recognition, on the other hand, they write, “may have serious consequences in interpersonal contexts.” Moreover, decreased ability to read emotions could point to a higher likelihood of non-verbal miscommunication and conflict. Given the significance of these implications, the authors conclude that further research is “mandatory.”

New studies would help researchers better understand how type, time taken, and duration of certain birth control pills influence emotional receptivity. It would also aid in identifying the exact mechanism by which emotional recognition is compromised.