Fun facts about menstrual cycle Do you know what happens to your body?

The menstrual cycle, the bane of our existence. It arrives (more or less) on time, doesn’t always last just one week, involves the entire body, disrupts both physical and emotional balance, triggers anxiety at school and work, and brings sweating and cramps along with it. We worry about hiding it, about not staining our favourite jeans, but almost never about truly understanding it. About understanding its effects on our body, about grasping what actually happens when this so-called cursed menstrual cycle begins. The topic is complex. The cycle has different phases, affects multiple areas of the body (some you wouldn’t expect), and is difficult to track. It varies from person to person, has few fixed points, and even cycle-tracking apps come with their own blind spots. In short: it’s exhausting.

Things you (probably) don’t know about the menstrual cycle

It affects the brain (yes, really)

It’s not just a mood issue (even though, let’s be honest, that part is real too). Studies and research are increasingly pointing to something deeper. During the cycle, the volume and connectivity of certain brain regions appear to change, and oestrogen and progesterone may influence memory, emotions, perception of reality, and decision-making processes. This is not suggestion or “just” emotionality. In fact, the cycle acts directly on the human brain, influencing impulsivity, risk assessment, and stress response. A lot suddenly makes sense, doesn’t it?

It can even change your voice

Once again, it’s the hormones (especially oestrogen) that during the cycle can alter the tone and stability of the voice. A detail that might matter a lot for singers or anyone working with their voice, and something most people don’t expect at all.

The amount of blood is far less than you think

The amount of blood lost during menstruation is often overestimated, because what is observed is not pure blood but a mixture of blood, endometrial tissue, and uterine secretions. Under normal physiological conditions, the average volume is around 30–40 millilitres per cycle, with a normal range considered between roughly 10 and 80 millilitres, according to clinical guidelines.

Sensitivity to smells can change

The cycle also acts on the digestive system and gut, which in turn is linked to another lesser-known effect: smell perception. In ovulatory phases, some people show increased olfactory sensitivity, and the perception of odours can change (including body odours). It’s the brain adjusting the senses in response to hormonal shifts.

The menstrual cycle is never exactly the same

The menstrual cycle is often described as linear, predictable, almost standardised. In reality, it is the opposite: one of the few biological systems that continuously shifts state, involving hormones, the brain, metabolism, the immune system, and even sensory perception at once. There is no fixed baseline, but rather a sequence of micro-equilibria that change within days. And this is the most overlooked point: there is no universal version of the cycle, but an extremely wide physiological variability, where each body follows its own rhythm. Rather than something to control or fix, it is a dynamic system to understand—and perhaps, for that very reason, one of the most complex and least understood processes of the human body.