Many women will complain about their monthly cramps, the food cravings, and the memory lapses during their menstrual cycle. But, when it comes to the brain, fluctuating hormone levels are not behind the bouts of sluggishness or forgetfulness. A recent study published in Frontiers in Behavioral Neuroscience found a woman's menstrual period has no effect on her ability to think.

A woman's ability to perform cognitive tasks was not impaired by the change in hormone levels throughout the month. However, progesterone and testosterone — two key hormones in the menstrual cycle — were associated with changes in working memory across one cycle in some women, but these effects weren't repeated in the second round. This suggests there's a learning curve effect.

Read More: How Fluctuating Hormone Levels Impact Cognitive Function During Your Period

“The hormonal changes related to the menstrual cycle do not show any association with cognitive performance,” said lead study author Dr. Brigitte Leeners of University Hospital Zurich, in a statement.

Leeners and her colleagues recruited 68 women and followed them across two consecutive menstrual cycles. They observed three brain functions, asking participants to perform 10 cognitive tests lasting about 40 minutes on a touch screen computer measuring divided attention; visual-spatial working memory, or the ability to remember shapes and colors and their movements; and cognitive bias, flaws in judgement or the way people think when processing information. These tests were conducted to track any possible changes in the three brain functions at different stages in the menstrual cycle.

Typically, a woman's menstrual cycle lasts 28 days and consists of three phases, including the follicular (before the egg is released), ovulatory (the egg release), and luteal (after the egg is released, also known as the time between ovulation and menstruation). Hormone levels vary throughout these predefined days during menstrual cycles. During the beginning of a woman's cycle, estrogen levels are low, and then increase, testosterone increases during menstruation, and progesterone is lowest at this time.

The findings concluded levels of estrogen, progesterone, and testosterone in a woman's body have no influence on her working memory, cognitive bias, or her ability to multitask. Leeners does admit there may be individual exceptions, but overall, cognitive performance is not disturbed by hormonal changes during a woman's monthly cycle. Although one-third of the women had endometriosis, or polycystic ovarian syndrome, the results still held true after researchers controlled for problems with the endocrine system.

Contrastingly, a 2014 study published in the journal Pain found menstrual cramps have a noticeably negative effect on a woman’s ability to perform tasks. Women with period pains had a lower performance rating compared to their non-period counterparts as they struggled with attention-based jobs, such as competing targets and dividing their attention between two tasks.

Leeners is quick to distinguish her study from the rest who have found hormonal changes do affect a woman's cognitive functioning. Previous studies on the subject have involved smaller sample sizes that only focused on hormones' influence on cycle. However, the researchers do note they only assessed three brain functions, which means their results are only applicable for those types.

Read More: Menstrual Cycle Helps Female Brain Grow

Moreover, there are always exceptions; there may be some women whose periods do affect cognition, but this warrants further research. Understanding hormone fluctuations during the menstrual cycle and how they affect the brain can help doctors and women alike comprehend why they feel the way they do during their period.

Blaming your hormones for period brain may no longer be a valid excuse on forgetting your friend's birthday.

Source: Leeners B, Kruger THC, Geraedts K et al. Lack of Associations between Female Hormone Levels and Visuospatial Working Memory, Divided Attention and Cognitive Bias across Two Consecutive Menstrual Cycles. Front. Behav. Neurosci. 2017.

See Also:

7 Little-Known Things About Periods And The Female Body

6 Easy-To-Do Yoga Poses That Will Relieve Your Period Symptoms