The follicular phase starts on the first day of menstruation and lasts until ovulation, spanning approximately 10 to 14 days. This phase is characterised by the development of ovarian follicles. The pituitary gland in your brain releases follicle-stimulating hormone (FSH) to stimulate the growth of several of these follicles, with one typically maturing into an egg.

• Hormonal changes: Rising levels of FSH and oestrogen.
• Common symptoms: Increased energy levels, a more positive mood, and clearer skin. Changes in discharge, which becomes clearer and more stretchy.

How do these changes impact the brain?

During the follicular phase, rising oestrogen levels boost brain connectivity and serotonin levels. This surge enhances mood, energy, and cognitive functions like memory and focus, by improving the efficiency of neural networks across the brain.

Hormonal fluctuations during the menstrual cycle significantly impact neuroplasticity. Research, including studies by Barth et al. (2016), has shown that hippocampal plasticity varies with the menstrual cycle, particularly noting increased brain connectivity with rising oestrogen levels during the late follicular phase. At the molecular level, research shows a correlation between oestrogen and increased neuronal plasticity, partly due to higher levels of neurotrophic factors like Brain-derived Neurotrophic Factor (BDNF), a key indicator of neuroplasticity (Zhou et al., 2005; Brinton, 2009). All this to say, that while your oestrogen levels rise, your brain becomes more adaptable, enhancing cognitive functions such as memory, learning, and emotional regulation.