Oestrogen, Serotonin and Dopamine: The Chemistry Behind Perimenopausal Mood

Flat, unmotivated, anxious, all at once, understanding the actual chemistry behind these changes will not fix them overnight, but it can do something valuable, it turns a confusing tangle of feelings into a picture with real, identifiable parts, and that can help make the experience feel less frightening.

Two different chemicals, two different jobs

Serotonin and dopamine are often talked about together, but they have different roles. Serotonin is closely tied to contentment, calm and a general sense of steadiness. Dopamine works on anticipation, motivation and the drive to actually do something, the difference between feeling calm and feeling like you want to get up and start your day.¹ When women describe feeling flat rather than sad, that flatness often points more toward the dopamine side of this picture than the serotonin side.

Oestrogen's relationship with serotonin

Oestrogen exerts profound effects on mood, mental state and memory, acting directly on the brain's serotonin and other neurotransmitter systems, a mechanism that has been documented in the scientific literature for decades.² Low levels of oestrogen are associated with premenstrual syndrome, postnatal depression and low mood after menopause, precisely because of this relationship.² As oestrogen fluctuates unpredictably through perimenopause, this serotonin relationship becomes less steady, which is the biological component behind the anxiety and low mood so many women describe.

What affects dopamine

Chronic stress dampens dopamine, and cortisol, your body's primary stress hormone, works against the very system responsible for motivation and drive, which is part of why prolonged stress leaves you feeling flat rather than simply tired.³ Nutritional factors may also play a role, iron is required for dopamine production and iron deficiency is common in women still menstruating heavily during perimenopause, low iron can contribute to fatigue, poor concentration and reduced motivation. Magnesium and vitamin D have both been associated with mood in some research, though the evidence for their specific role in perimenopausal mood is less settled than the iron connection. Testosterone plays a role as well, it increases dopamine release directly, which is one reason testosterone decline through perimenopause can show up as a loss of motivation and drive distinct from ordinary sadness.³

Did you know? Iron, magnesium and vitamin D are among the micronutrients worth checking in midlife women presenting with low mood and low motivation.³ This is worth discussing directly with your GP, standard blood tests, iron studies, vitamin D, and where relevant vitamin B12, can clarify whether a genuine deficiency is contributing.

Why movement and novelty genuinely help

Getting out of your head and into your body has a real chemical basis. Exercise, music, and new experiences all increase dopamine release, which is part of why a walk, a new class, or simply doing something different from your routine can shift a flat mood in a way that resting alone often cannot.³ This does not mean pushing through exhaustion, it means recognising that dopamine responds to genuine engagement and novelty, not passivity.

What this means for you

Mood in perimenopause is at least two distinct systems, serotonin and dopamine, both shifting as oestrogen, progesterone and testosterone fluctuate, alongside the separate influence of chronic stress. Naming which part of this picture you are experiencing gives you a much more useful starting point for a GP conversation than a general "I just feel awful." Try instead, "I feel anxious and on edge," or "I'm not anxious, I just can't find any motivation," that distinction alone gives both you and your GP a clearer place to start.

Three takeaways

1. Serotonin and dopamine do different jobs, serotonin supports calm and contentment, dopamine drives motivation and drive, and naming which one feels affected helps you describe your experience more precisely.

2. Oestrogen's relationship with serotonin is well established, while chronic stress and low testosterone have a clearer link to dopamine, and iron, magnesium and vitamin D may also play a role, though the evidence for the latter two is less settled.

3. Iron, magnesium, vitamin D and vitamin B12 are all checkable through standard GP blood tests, worth raising if low mood or low motivation persists.

This is not your body failing you. It is your body changing, and asking for a different kind of support.

This information is educational only and does not constitute personal medical advice. Always consult a qualified health professional about your individual circumstances. © Menopause Hub 2026.

REFERENCES

1. Casperson K. You Are Not Broken: Stop "Should-ing" All Over Your Sex Life. Self-published/YANB Media; 2022. [Chapter 7, The Chemistry of Pleasure]

2. Fink G, Sumner BE, Rosie R, Grace O, Quinn JP. Estrogen control of central neurotransmission: effect on mood, mental state, and memory. Cellular and Molecular Neurobiology. 1996;16(3):325 to 344.

3. Casperson K. You Are Not Broken. Self-published/YANB Media; 2022. [Chapter 7, The Chemistry of Pleasure; Chapter 13]