Ovarian hormones significantly influence behaviour and cognitive function and the dance between these hormones and brain chemistry ultimately shapes a women’s experience of her menstrual cycle. It is estimated that 80-97% of women worldwide and across age groups experience at least one symptom of premenstrual syndrome (PMS) in their reproductive years. Mental fatigue, mood disturbance and cognitive dysfunction are common during the mid-luteal phase. L-theanine increases the secretion and function of neurotransmitters such as GABA and may improve mental acuity and lift the brain fog.

The exact aetiology of how ovarian hormones influence cognitive function remains unknown, but the general consensus is that premenstrual symptoms are caused by increased central nervous system sensitivity to fluctuation in menstrual cycle hormones. Most of the research into the hormone-cognition relationship has explored the levels of oestrogen as the modulator of cognitive performance. However, there are studies that show the influential role of progesterone. For example, in the luteal phase reduced concentrations of allopregnanolone, a progesterone precursor may also lead to an impaired GABA-mediated response and could explain the psychoneuroendocrine symptoms that occur in PMS.

PMS symptoms security is linked to poorer cognitive function. Executive functioning and working memory were shown to be impaired in women with the premenstrual dysphoric disorder, with a worsening of symptoms in the luteal phase.

Studies have released higher executive performance in the early luteal phase when progesterone levels are at their peak, in contrast to the late luteal and ovulation phase. Researchers have found that women with PMS have reduced GABA receptor sensitivity in the brain and may have lower progesterone concentrations than those not experiencing PMS. Sleep quality is also influenced by menstrual cycle phases with a disturbance reported to occur more frequently in the mid to late luteal phase when progesterone levels drop rapidly.

L-theanine has been shown to modulate dopamine and serotonin levels in the brain through the release of the inhibitory neurotransmitter GABA, thereby supporting cognitive function, learning and attention, and supporting healthy mood balance. Behavioural studies in animals demonstrate improvements in memory and learning following L-theanine administration. Several studies have shown that doses of 50-200mg significantly increase the pattern intensity of alpha brain waves in the cerebral cortex producing a relaxed but alert mental state. Doses of 200mg reported a profound effect on attention performances as well as on reaction time responses in normal healthy subjects prone to high anxiety. In human trials, administration of 250mg and 400 mg had profound and positive modulator effects on sleep quality.

Taking 200mg of L-theanine, in conjunction with 10mg of activated B3, prevents brain fog, increases concentration and supports cognitive function within half an hour of administration.