18/03/2026
If you feel like your whole personality has shifted in Peri, youâre not alone. Irritability is one of the most common symptoms I see, because during perimenopause, several hormonal changes affect emotional regulation.
Fluctuating estrogen destabilises serotonin, dopamine, and GABA signalling, while also increasing stress reactivity through the HPA axis. At the same time, progesterone levels often fall as ovulation becomes less consistent. Progesterone and its metabolites normally have calming effects on the brain through GABA receptors, so lower levels can reduce emotional buffering.
Sleep disruption also plays an important role. Insomnia and fragmented sleep reduce cognitive capacity and emotional tolerance, making it harder for the brain to regulate frustration and stress.
The combination of hormonal signalling changes and sleep disruption can lower the threshold for irritability.
Naturally, many women with existing PMS and PMDD will also find that these conditions worsen in perimenopause as well.
Importantly, managing sleep and our other tools to regulate like exercise and mindfulness will help. Appropriate MHT will too!