Hormones act as the body's internal signals. They regulate mood, sleep, metabolism, and fertility. During the reproductive years and through menopause, four hormones play a central role: oestradiol, progesterone, LH (luteinising hormone), and FSH (follicle-stimulating hormone). As the body transitions out of its reproductive phase, each of these shifts in distinct ways.

Understanding what is happening and when makes it easier to recognise your own experience and respond to it with informed care.

Hormones during the menstrual cycle

How hormones move through the menstrual cycle

The menstrual cycle has two main phases. Each has a different hormonal profile, and each produces a different felt experience.

The follicular phase

The follicular phase begins on the first day of menstruation and continues until ovulation, roughly two weeks. During this time, FSH and LH rise to stimulate the growth of follicles in the ovaries, each containing an egg. One becomes dominant and continues to mature.

As the dominant follicle grows, oestradiol rises. It thickens the uterine lining in preparation for a possible pregnancy, and also influences mood, focus, and energy. Research links higher oestradiol levels in the late follicular phase with improved mood, motivation, and social engagement [1, 2]. For many women, this part of the cycle feels more outward, energised, and clear-headed.

The luteal phase

After ovulation, the empty follicle becomes the corpus luteum and begins producing progesterone. This hormone maintains the uterine lining and has a calming effect on the nervous system, supporting sleep and emotional steadiness. Research associates higher luteal progesterone with more stable mood and better emotional regulation [3].

Oestradiol drops after ovulation, then rises slightly again before falling toward the end of the phase. As both hormones decline in the late luteal phase, the brain feels it. Oestradiol interacts with serotonin and dopamine; as levels fall, mood, motivation, and mental clarity can soften [4]. For some women, this shows up as restlessness, disrupted sleep, or tension before menstruation.

If no pregnancy occurs, both hormones fall and the uterine lining sheds. A new cycle begins.

What changes during perimenopause

Perimenopause begins when hormone levels start to fluctuate unpredictably. Oestradiol and progesterone no longer follow a steady cycle, which disrupts ovulation. In response, LH and FSH can spike higher than usual as the body attempts to stimulate the ovaries [5, 7].

This hormonal variability, rather than simply low hormone levels, is what drives many of the symptoms associated with perimenopause: hot flashes, night sweats, mood changes, irregular periods, and disrupted sleep. The phase can last several years [6, 8].

Estrogen concentration level during the different menopause phases.

The menopause marker

Menopause is confirmed after twelve consecutive months without a period. At this point, oestrogen and progesterone levels are consistently low. The ovaries no longer release eggs, and LH and FSH remain elevated. The reproductive phase is complete [5, 6].

Postmenopause: a new hormonal baseline

After menopause, hormone levels stabilise at a lower baseline. Many early symptoms ease as the body adapts to this new state. Oestradiol continues to be produced in small amounts by the adrenal glands and other tissues, though at levels significantly lower than during the reproductive years [7, 9].

Long-term health priorities shift during this phase. Bone strength, cardiovascular health, and metabolic function all benefit from consistent attention through nutrition, movement, and rest [6, 8].

What these shifts mean for the body

Hormonal change affects multiple systems simultaneously. Declining oestrogen is associated with hot flashes, night sweats, and changes in skin and hair. Reduced progesterone can affect sleep quality and emotional steadiness. Elevated cortisol from ongoing stress adds further pressure on weight and energy regulation [5, 6].

These are physiological responses to real hormonal change, not personal failings. Consistent habits, balanced nutrition, regular movement, and managed stress all support the body through this adjustment.

Vitamin D3, vitamin K2, and DHA are among the nutrients that become more relevant during and after the menopause transition, particularly for bone strength, cardiovascular health, and cognitive function. If dietary intake or sun exposure is limited, speak with a healthcare professional about whether supplementation is appropriate for you [8, 9].

In short

Oestradiol, progesterone, LH, and FSH each play a distinct role through the menstrual cycle and across the menopause transition. Their shifts are gradual and individual. Perimenopause is characterised by unpredictable fluctuation. Menopause marks the point of confirmed hormonal change. Postmenopause brings a new, lower baseline. Understanding this pattern helps make sense of what the body is doing and why.

FAQ

Which hormone is most responsible for hot flashes? Fluctuating oestradiol levels are the primary driver. It is the unpredictability of the fluctuation, particularly during perimenopause, rather than simply low levels, that triggers the thermoregulatory response [5, 6].

Why do FSH levels rise during menopause? As oestrogen falls, the body increases FSH in an attempt to stimulate the ovaries. During menopause, the ovaries no longer respond to this signal, so FSH remains elevated [5, 7].

Can I test my hormone levels? Yes. Blood tests measuring FSH, LH, and oestradiol can give useful information about where you are in the transition. Results are best interpreted by a healthcare professional and should use an accredited laboratory for accuracy.

How does progesterone affect mood and sleep? Progesterone has a calming effect on the nervous system. Higher luteal levels are associated with more stable mood and better sleep. As progesterone declines during perimenopause and menopause, some women notice increased restlessness or lighter sleep [3, 4].

Can lifestyle habits genuinely support hormonal health? Consistent sleep, regular movement, and balanced nutrition all support the body's ability to manage hormonal change. They do not alter the transition itself, but they influence how the body responds to it [6, 8, 9].

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This article is for informational purposes only and is not medical advice.

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Sources

• [1] Albert K et al. — Oestradiol levels modulate brain activity and mood in women. Frontiers in Neuroendocrinology. 2015.

• [2] Hromatko I et al. — Mid-cycle rise in positive and drop in negative moods. Brain Sciences. 2023.

• [3] Ziomkiewicz A et al. — Higher luteal progesterone is linked with lower premenstrual mood symptoms. Psychoneuroendocrinology. 2012.

• [4] Sundström-Poromaa I et al. — Menstrual cycle influence on cognitive function and the role of hormones. Frontiers in Neuroscience. 2014.

• [5] Harvard Health Publishing — Menopause and hormone changes. 2023.

• [6] Cleveland Clinic — Understanding oestrogen and progesterone. 2023.

• [7] The North American Menopause Society (NAMS) — Hormone function through menopause. 2022.

• [8] European Menopause and Andropause Society (EMAS) — Hormonal changes and clinical guidance. 2022.

• [9] National Health Service (NHS UK) — Menopause and hormone balance. 2023.