There is a moment in every menstrual cycle where something shifts. Energy rises. Confidence follows. The conversation you have been putting off suddenly feels manageable, the presentation you were dreading feels within reach. This is not imagination. It is oestrogen, and the science behind it is considerably more interesting than most of us have been told.

During ovulation, rising oestrogen levels produce measurable improvements in mood, cognitive function and social confidence. A study by hormonal health company Mira found that employees who menstruate feel twice as productive during their ovulation days compared to other points in the cycle.

Women's health expert Valentina Milanova is specific about what this means in practice. "During ovulation, hormonal changes can enhance mood, energy, and cognitive function, leading to a sense of heightened productivity. This is also the time when we have the highest levels of confidence and the highest levels of wanting to be social." Her advice follows directly from the data: schedule your board meetings, have the challenging conversations, ask for the promotion. Time it right and your biology is working with you.

This is the version of the menstrual cycle conversation that rarely gets told, and it is worth sitting with. The cycle is not simply a monthly inconvenience to be managed. Understood properly, it is a map of fluctuating strengths, and the ovulatory phase represents a genuine cognitive and interpersonal peak that most women are not deliberately harnessing.

The follicular phase, which precedes ovulation, also tends to bring rising energy and an openness to new ideas as oestrogen begins to climb. This is often a productive time for creative thinking, strategic planning and taking on new challenges. Women who understand their own cycle can learn to lean into these phases rather than working against them by accident.

The full picture, of course, is more complex. The luteal phase, which follows ovulation and precedes menstruation, brings rising progesterone that can lead to fatigue, mood changes and reduced concentration. For many women this is a time better suited to focused, independent work than high-stakes social performance. And then there is menstruation itself, where the data is harder to ignore. The British Medical Journal has estimated that period pain and PMS symptoms account for between nine and twelve lost productive days per year. Research by the Chartered Institute of Personnel and Development found that 69% of women feel their period has a negative impact on their work, with 61% working on days when they do not feel well enough to do so.

These are not minor figures. They describe the majority experience of roughly half the workforce, playing out quietly every month with almost no structural acknowledgement from the organisations in which it happens. "This doesn't mean that women are less productive than men," Milanova says, "but that we need a different kind of environment in order to thrive." The distinction matters. This is not an argument for lowered expectations. It is an argument for smarter design.

Psychotherapist and careers coach Eloise Allexia advocates for workplaces that give employees the autonomy to structure their own workloads across the month, moving faster on projects at peak times and allowing a slower pace when energy is lower. Milanova points to flexible working hours, remote options and the ability to take short breaks as practical starting points that would make a significant difference for most women without requiring dramatic structural change.

The conversation cannot stop at the cycle itself. Women's health expert and gynaecologist Anna Targonskaya points to the significant proportion of women managing hormonal conditions alongside their working lives. Endometriosis affects around 10% of women worldwide. Polycystic ovarian syndrome affects between 8% and 13%. "With around 20% of women suffering from hormone conditions during reproductive years, and considerably more during the transition to menopause, it is vital for workplaces to have inclusive and supportive policies in place," she says.

There is currently no UK law requiring employers to offer menstrual leave, and the debate around whether such legislation is the right approach remains live. What is less debatable is the cost of inaction. Organisations that build genuine flexibility around menstrual health, train managers to have informed conversations, and normalise rather than pathologise the subject stand to benefit directly in retention, engagement and the sustained performance of people who would otherwise be quietly managing an avoidable burden alone.

The menstrual cycle is not a liability. Understood properly, it is a map. The workplaces that learn to read it will be considerably better placed than those that continue to pretend it does not exist.