Sex hormones library
Understanding oestrogen, progesterone and testosterone
Hormones are often blamed for almost everything in midlife.
Weight gain. Poor sleep. Low mood. Brain fog. Reduced libido. Fatigue. Changes in body composition.
Hormones can certainly influence many of these areas — but the reality is more nuanced than simply having hormones that are “too high”, “too low” or “out of balance”.
During perimenopause, ovarian hormone production becomes more variable. Oestrogen and progesterone can fluctuate considerably before settling at lower levels after menopause, while testosterone follows a different pattern and does not simply fall off a cliff at menopause.
Understanding what each hormone does — and how the wider picture fits together — can make midlife health much easier to navigate.
In brief
Oestrogen, progesterone and testosterone all have important roles in women’s health, but they do not work in isolation.
Through perimenopause:
- oestrogen levels can fluctuate significantly before declining
- progesterone often becomes more variable as ovulation becomes less consistent
- testosterone generally changes more gradually with age
- symptoms do not always correlate neatly with a single hormone level
- sleep, stress, nutrition, medication, thyroid function and metabolic health can influence how you feel
- hormone blood tests are not always necessary or useful for identifying perimenopause
- treatment decisions should be based on the wider clinical picture
The goal is not to chase a perfect hormone level.
It is to understand what may be changing and what support is appropriate.
What are hormones?
Hormones are chemical messengers.
They are produced in one part of the body and travel through the bloodstream to influence activity elsewhere.
Oestrogen, progesterone and testosterone are often grouped together as “sex hormones”, but their effects extend far beyond reproduction.
They interact with:
- the brain
- bone
- muscle
- cardiovascular tissues
- skin
- the reproductive system
- metabolism
- sexual function
Their actions also overlap.
That is one reason why symptoms cannot always be attributed neatly to a single hormone.
Oestrogen
Oestrogen is not one single hormone.
The main forms include oestradiol, oestrone and oestriol.
During the reproductive years, oestradiol is the dominant circulating form and is produced primarily by the ovaries.
Oestrogen plays roles in:
- menstrual-cycle regulation
- ovulation and reproduction
- bone health
- vaginal and urinary tissues
- temperature regulation
- cardiovascular physiology
- brain function
- skin and connective tissues
- aspects of body-fat distribution
As ovarian function changes through perimenopause, oestrogen levels can become erratic rather than simply declining in a straight line.
That variability helps explain why symptoms can come and go.
What can changing oestrogen feel like?
Changes in oestrogen may contribute to symptoms such as:
- hot flushes
- night sweats
- changes in menstrual cycles
- vaginal dryness or discomfort
- urinary symptoms
- sleep disturbance
- changes in mood
- changes in body composition
But these symptoms are not unique to oestrogen change.
Poor sleep, thyroid dysfunction, medication, stress, nutrient deficiencies and other medical conditions can produce overlapping symptoms.
That is why I prefer to avoid assuming every symptom in a woman over 40 is “low oestrogen”.
Progesterone
Progesterone is produced mainly after ovulation.
During a typical menstrual cycle, levels rise after ovulation and help prepare the lining of the uterus for a possible pregnancy.
If pregnancy does not occur, progesterone falls and menstruation follows.
As ovulation becomes less predictable during perimenopause, progesterone production can also become more variable.
This can contribute to changing menstrual patterns.
Progesterone is also relevant clinically because when systemic oestrogen is prescribed as HRT to someone who still has a uterus, a progestogen is generally needed to protect the uterine lining. NHS guidance explains that oestrogen and progestogen are the main hormones used in HRT.
Progesterone and sleep
Progesterone is often promoted online as a “calming hormone”.
There is some physiological basis for interest in progesterone and the nervous system, but it is too simplistic to say that low progesterone is the cause of anxiety, poor sleep or irritability in every woman.
Sleep disruption during perimenopause can be influenced by:
- night sweats
- hot flushes
- stress
- mood
- alcohol
- caffeine
- sleep habits
- medication
- other health conditions
So again, the useful question is not:
“Is my progesterone low?”
It is:
“What is contributing to my sleep problem?”
Testosterone
Women produce testosterone too.
It is produced by the ovaries and adrenal glands and also arises through conversion from other hormones.
Testosterone contributes to areas including:
- sexual function
- libido
- muscle physiology
- bone
- general wellbeing
But testosterone behaves differently from oestrogen and progesterone through midlife.
Research suggests testosterone levels tend to decline with age rather than falling specifically because menopause occurs. A large recent analysis found declining concentrations from around age 40, with natural menopause itself not appearing to cause the decline.
This matters because the popular idea that menopause automatically creates “testosterone deficiency” is misleading.
What about testosterone treatment?
This is an area where social media has moved much faster than the evidence.
Current British Menopause Society guidance states that the evidence-based indication for testosterone supplementation is persistent, distressing low sexual desire in appropriate postmenopausal women after other contributory factors have been addressed.
NHS guidance similarly describes testosterone as an option that may help some women with low libido, usually under specialist care.
There is not currently good evidence to support testosterone as a general treatment for:
- fatigue
- brain fog
- weight gain
- low mood
- loss of muscle
- prevention of dementia
- prevention of bone loss
That does not mean testosterone has no role.
It means its role should be appropriately defined.
Hormones do not work alone
This is one of the most important points.
Hormones interact with the wider physiology of the body.
For example:
Sleep
Hormonal changes may disrupt sleep, while poor sleep can affect appetite, glucose regulation and energy.
Muscle
Ageing, activity levels, nutrition and hormonal change can all influence muscle.
Blood glucose
Changes in body composition, movement, sleep and central fat can affect insulin sensitivity.
Thyroid function
Thyroid symptoms can overlap with menopausal symptoms.
Stress
Stress does not “switch off” female hormones, but it can influence sleep, appetite, mood and symptom perception.
Nutrition
Nutrition supports the systems that use and metabolise hormones, but food does not “rebalance” hormones in a simple on/off way.
This is why I prefer to think in terms of patterns and interactions rather than one hormone being the cause of everything.
What does “hormone balance” really mean?
The phrase is everywhere.
But clinically, there is no single measurable state called “perfect hormone balance”.
Hormone levels change:
- throughout the menstrual cycle
- across the day
- with age
- with medication
- with reproductive stage
- in response to illness and stress
So rather than promising to “balance hormones”, I prefer to ask:
Are the symptoms consistent with the menopausal transition?
Could another condition be contributing?
Is medical assessment needed?
What lifestyle and nutritional factors can support the wider picture?
That is a more useful and defensible approach.
Do you need hormone testing?
Not necessarily.
For women over 45 with typical menopausal symptoms, NICE guidance generally supports diagnosis based on symptoms and menstrual history rather than routine hormone blood testing.
Hormone tests can be difficult to interpret during perimenopause because levels may fluctuate considerably.
A single result is a snapshot.
It does not always explain symptoms.
There are circumstances where testing may be appropriate, particularly if:
- symptoms occur at a younger age
- menstrual changes are unusual
- another diagnosis is being considered
- treatment decisions require additional information
- symptoms do not fit the typical picture
The key question is:
Will the result change what we do?
What about DUTCH testing?
The DUTCH test measures a range of hormones and hormone metabolites using dried urine.
It can provide additional information in selected situations, but it is not a requirement for diagnosing perimenopause or menopause.
I do not believe every woman needs advanced hormone testing.
If I consider testing, I want to know:
- what question we are trying to answer
- whether standard medical testing already gives us enough information
- whether the result will genuinely influence the plan
More data does not automatically mean better care.
[Explore: Understanding DUTCH hormone testing →]
What I look at in practice
When a woman comes to me with concerns about hormones, I do not begin by assuming the answer is hidden in a hormone panel.
I look first at the wider pattern.
What has changed?
Are periods changing?
Is sleep different?
Has body composition changed?
What is happening with energy, mood or libido?
Where are you in the menopausal transition?
Age, menstrual pattern and symptoms can provide important context.
What else could explain the symptoms?
Thyroid function, iron status, medication, stress, sleep and metabolic health may need consideration.
What is your nutritional picture?
Are meals adequately nourishing?
Is protein sufficient?
Is fibre intake appropriate?
Is alcohol playing a role?
What does your existing health data show?
GP blood results can often provide useful information before additional testing is considered.
Jo’s perspective
I think one of the biggest problems with hormone information online is the tendency to reduce everything to a single explanation.
Low oestrogen. High cortisol. Low progesterone. Low testosterone.
The body is rarely that simple.
I am much more interested in how symptoms, hormonal stage, sleep, metabolic health, nutrition, medication and lifestyle fit together.
Sometimes the key issue is clearly related to menopausal change.
Sometimes something else deserves attention.
And sometimes both things are true.
My approach is not to chase a perfect hormone number.
It is to understand the pattern well enough to decide what deserves attention next.
What can nutrition support?
Nutrition cannot stop menopause.
It cannot restore ovarian hormone production.
But it can support many of the systems that become increasingly important through midlife.
Useful areas to consider may include:
- adequate protein
- fibre-rich foods
- vegetables, fruit and wholefoods
- calcium and vitamin D intake
- oily fish and other sources of omega-3 fats
- maintaining a healthy relationship with food
- reducing excess alcohol
- supporting metabolic health
- eating in a way that supports muscle and bone
Nutrition works best alongside:
- movement
- resistance training
- adequate sleep
- appropriate medical care
- HRT where chosen and clinically appropriate
What about HRT?
Hormone replacement therapy is a medical treatment used to help manage menopausal symptoms.
The main hormones used are oestrogen and, where required, a progestogen. Testosterone may sometimes be considered for persistent low sexual desire in selected women.
HRT decisions should be made with an appropriately qualified medical professional who can discuss:
- symptoms
- medical history
- personal risk factors
- type of HRT
- route of administration
- benefits and risks
Nutritional therapy does not replace HRT or medical assessment.
My role is to support the wider nutritional and lifestyle picture alongside appropriate medical care.
When should you speak to your GP?
Seek medical advice if you have:
- bleeding that is very heavy or unusual
- bleeding after menopause
- symptoms that are severe or concerning
- symptoms that do not fit the typical menopausal pattern
- significant mood changes
- unexplained weight change
- possible thyroid symptoms
- concerns about HRT or medication
- symptoms beginning unusually early
Medical assessment is particularly important if something feels new, persistent or different from what you would normally expect.
Connect the dots
Perimenopause and metabolism
How hormonal change interacts with ageing, muscle, sleep and metabolic health.
[Read the guide →]
Protein and muscle through midlife
Why maintaining muscle is increasingly important as we age.
[Read the guide →]
Understanding thyroid blood tests
Why thyroid symptoms and menopausal symptoms can overlap.
[Read the guide →]
Understanding blood glucose and HbA1c
How metabolic markers can add context to your wider health picture.
[Read the guide →]
Want help understanding your own hormonal picture?
Your Body Library can explain the science.
But symptoms need context.
If you would like personalised support, I can help you look at your symptoms, nutrition, lifestyle, health history and relevant results together and identify which areas deserve attention.
[Explore nutritional therapy →]
[Book a discovery call →]
This page is for educational purposes and is not a substitute for medical diagnosis or treatment. Hormone replacement therapy and prescription medication should be discussed with an appropriately qualified medical professional.
References & further reading
- NICE. Menopause: identification and management (NG23). Updated April 2026.
- NHS. Hormone replacement therapy (HRT).
- NHS. Treatment for menopause and perimenopause.
- British Menopause Society. Testosterone replacement in menopause.
- British Menopause Society. Statement on testosterone.
- Wang Y et al. Testosterone and pre-androgens by age and menopausal status in women.
- Burger HG et al. Hormonal changes during the menopausal transition.