4 / Menopause Blood Tests: What is Actually Worth Checking?
Updated: 17 hours ago
Your periods have changed. Your sleep is different. Perhaps you are having hot flushes, mood changes, brain fog, fatigue or changes in weight and libido.
So the obvious question is: How do I actually know whether I am in perimenopause?
For most healthy women over 45, the answer comes primarily from age, changes in the menstrual cycle and typical symptoms, not from a hormone panel. But blood tests can still be extremely useful when we use them to answer the right questions.
How do I know if I am in perimenopause?
Perimenopause usually begins with changes in a previously established menstrual pattern. Cycles may initially become shorter, then more variable. Ovulation becomes less predictable and eventually longer gaps between periods appear.
At the same time, symptoms such as hot flushes, night sweats, disturbed sleep and mood changes may develop. You can absolutely be in perimenopause while still having periods, and sometimes while they still appear reasonably regular.
For a woman over 45 with typical symptoms and cycle changes, perimenopause can usually be identified clinically without hormone testing.
Menopause is different. Natural menopause is confirmed retrospectively after 12 consecutive months without a menstrual period, assuming there is no other reason for menstruation to have stopped.
What can FSH actually tell you?
FSH, or follicle stimulating hormone, is produced by the pituitary gland. As ovarian follicles decline and the ovaries become less responsive, feedback between the ovaries and brain changes and FSH generally rises.
But perimenopause is not hormonally stable.
Ovarian activity can vary considerably from one cycle to another, so FSH can rise and fall too. A normal FSH therefore does not rule out perimenopause, and one elevated result does not tell us exactly where you are in the transition.
If biochemical testing is clinically useful and you are still menstruating, FSH is best measured in the early follicular phase, approximately cycle days 2 to 5, with day 1 being the first day of bleeding. Estradiol can be measured alongside it to help with interpretation. If periods have become very infrequent, FSH can instead be assessed after a prolonged interval without menstruation.
An early follicular FSH above approximately 25 IU/L can be strongly suggestive of perimenopause, but there is no single diagnostic cutoff that works for every woman.
This is why I don't consider FSH useless. I consider random FSH testing without clinical context considerably less useful.
When does hormone testing become more important?
For an otherwise healthy 50 year old with irregular periods, hot flushes and night sweats, an FSH result may add very little to what we already know.
Age changes that calculation.
Between 40 and 45, biochemical testing may be appropriate when menopause is suspected. If menstrual irregularity or symptoms of estrogen deficiency occur before 40, proper investigation for premature ovarian insufficiency and other possible causes is important.
Testing may also be appropriate when symptoms are unusual, the menstrual pattern cannot be used reliably, or another reproductive or endocrine condition is suspected.
The question should always be: Will this result help us understand what is happening or change what we do next?
Estradiol is a snapshot
Estradiol can fluctuate substantially during perimenopause. Some cycles may produce significant amounts while others produce considerably less.
That means one estradiol result cannot show us what estrogen has been doing over the previous month.
When FSH testing is indicated, estradiol can help with interpretation because higher estradiol can suppress FSH. But an isolated normal estradiol result does not prove that you are not perimenopausal, just as a low result does not automatically mean every symptom you have is caused by estrogen deficiency.
The blood test is a snapshot. Perimenopause is a moving picture.
What about progesterone?
Progesterone tells us something different.
After ovulation, the follicle that released the egg becomes the corpus luteum and produces progesterone. As ovulation becomes less consistent during perimenopause, progesterone production naturally becomes less predictable too.
If progesterone is being tested to determine whether ovulation occurred, it needs to be measured during the mid-luteal phase, rather than automatically on "day 21."
For example:
Day 21 only makes sense for someone with approximately a 28-day cycle.
A random low progesterone result can simply mean you did not ovulate that cycle or that the test was taken at the wrong time.
This is why I am cautious when women are diagnosed with "progesterone deficiency" from one poorly timed result. We need to understand the cycle before interpreting the number.
Testosterone does not suddenly disappear at menopause
Women produce testosterone through the ovaries and adrenal glands and through peripheral conversion of androgen precursors.
Unlike estrogen, testosterone does not suddenly collapse at the final menstrual period. Androgen concentrations generally decline gradually across adult life.
Testosterone testing may be appropriate when androgen excess is suspected or when testosterone treatment is being considered for an appropriate indication.
But there is no testosterone level that diagnoses low sexual desire in women.
Low libido can involve vaginal dryness or pain, poor sleep, medication, depression, stress, relationship factors, chronic illness and hormonal changes.
Testosterone can therefore be part of an assessment. It should not automatically become the explanation for every woman experiencing low libido, fatigue or loss of motivation.
Where does DHEA fit?
DHEA, or dehydroepiandrosterone, and its sulfated form DHEA-S are produced predominantly by the adrenal glands and act as precursors from which tissues can produce other androgens and estrogens.
DHEA levels generally decline gradually with age. This is not a menopause-specific collapse.
For that reason, DHEA-S is not a routine test for diagnosing perimenopause or menopause. It becomes more useful when there is a specific reason to investigate adrenal androgen production or another endocrine disorder.
Vaginal DHEA, known as prasterone, is a separate issue. It can be used locally as a treatment for genitourinary syndrome of menopause. That does not mean menopausal women generally need systemic DHEA supplementation.
Once you know it is probably perimenopause, look beyond your ovaries
This is where blood testing becomes far more interesting.
You can be in perimenopause and have something else going on at the same time.
Thyroid dysfunction can cause fatigue, weight changes, low mood, hair changes and menstrual irregularity. Iron deficiency can cause exhaustion, headaches, hair shedding and palpitations. Insulin resistance can develop while fasting glucose remains normal. Vitamin deficiencies, sleep disorders and other medical conditions can also produce symptoms easily blamed on menopause.
So once we recognise the hormonal transition, we shouldn't stop investigating.
We should widen the lens.
Check thyroid function when the symptoms fit
Thyroid dysfunction overlaps considerably with menopause symptoms.
TSH is generally the appropriate starting test, with free T4 providing additional information where indicated. Further testing, including thyroid antibodies, may be useful when the clinical picture suggests autoimmune thyroid disease or another thyroid disorder.
But ordering every possible thyroid marker for every woman is not better functional medicine.
Testing should answer a question.
Heavy periods and fatigue? Check iron
Perimenopausal bleeding can become heavier or more prolonged and gradually deplete iron stores.
A full blood count can identify anaemia, while ferritin gives us information about stored iron. Iron stores can become depleted before haemoglobin falls enough to meet the definition of anaemia.
That makes ferritin particularly relevant when fatigue, weakness, poor exercise tolerance, headaches, palpitations or hair shedding accompany heavy periods.
And if bleeding has become unusually heavy or prolonged, don't simply keep replacing iron. Investigate the bleeding itself.
Any bleeding after menopause also requires medical assessment.
Don't stop at fasting glucose
Fasting glucose tells us how much glucose is circulating after fasting, while HbA1c estimates average glucose exposure over roughly the previous two to three months.
Both are useful for identifying prediabetes and diabetes.
But insulin resistance can begin earlier. The pancreas may compensate by producing more insulin, keeping glucose within the normal range.
In selected women, fasting insulin can therefore add useful information when interpreted alongside glucose, waist circumference, triglycerides, HDL and the overall metabolic picture.
A normal fasting glucose is good news.
It simply isn't the entire metabolic story.
Look properly at cardiovascular risk
Menopause is also an important time to assess cardiovascular health.
At minimum, I want to know total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides.
Depending on individual risk, ApoB can add information about the number of atherogenic lipoprotein particles circulating in the blood.
Lp(a) is another important marker. It is largely genetically determined and represents an independent cardiovascular risk factor, so establishing it at least once can be useful, particularly when personal or family history warrants a closer look.
These markers may tell us considerably more about your future health than repeatedly measuring reproductive hormones.
Include liver health in the picture
The liver is central to the hormone metabolism and detoxification pathways we discussed in the previous article.
Markers such as ALT, AST, GGT, alkaline phosphatase and bilirubin can help identify liver or biliary abnormalities.
They do not directly measure how efficiently you are metabolising estrogen, and normal liver enzymes do not necessarily exclude metabolic fatty liver disease.
Liver markers therefore make most sense when interpreted alongside glucose regulation, triglycerides, abdominal adiposity, alcohol intake, medication and overall metabolic health.
Nutrient testing should have a reason
Vitamin D is particularly relevant to bone health and should be assessed when deficiency risk or the clinical picture warrants it.
Vitamin B12 can be worth checking with unexplained fatigue, neurological symptoms, restrictive diets, gastrointestinal problems or medications that interfere with absorption.
Folate may also be appropriate depending on diet, blood count and medical history.
The principle is simple: identify the risk, test where useful and correct what actually needs correcting.
You do not need an enormous micronutrient panel simply because you have reached menopause.
Some of the most important checks are not menopause blood tests
I want to know your blood pressure and waist circumference, and I want to understand changes in body composition.
Depending on age and individual osteoporosis risk, a DEXA scan may be appropriate to assess bone density.
Breast and cervical screening should be up to date according to national recommendations and personal risk.
And sleep, strength, physical activity, alcohol, smoking, bleeding patterns, sexual and urinary health, medications and family history all belong in the assessment.
So what would I actually check?
There is no universal menopause blood test panel. Testing should be guided by symptoms, medical history and individual risk.
For a useful midlife health assessment, I commonly consider:
Full blood count and ferritin for anaemia and iron status.
Fasting glucose and HbA1c, with fasting insulin where additional metabolic information is useful.
Total cholesterol, LDL C, HDL C and triglycerides, with ApoB and Lp(a) where appropriate.
TSH and free T4, with further thyroid testing when indicated.
ALT, AST, GGT, alkaline phosphatase and bilirubin for liver and biliary assessment.
Vitamin D, vitamin B12 and folate when symptoms, diet or medical history make them relevant.
Reproductive and androgen hormones such as FSH, estradiol, progesterone, testosterone and DHEA-S should be added when there is a specific clinical reason to measure them, rather than automatically because a woman is over 45.
And remember that blood pressure, waist circumference, body composition and bone density where indicated can be every bit as important as the blood work.
What I want you to take away from this series
Perimenopause is usually recognised from your age, changing menstrual pattern and symptoms rather than diagnosed from a single hormone result. Hormone testing can be useful when there is a specific question to answer, but a normal FSH does not rule out perimenopause and an abnormal hormone result does not automatically mean something needs treating.
Most importantly, don't let menopause become the explanation for everything. Recognise the hormonal transition, but investigate the woman as a whole. Thyroid dysfunction, iron deficiency, insulin resistance, cardiovascular risk, nutrient deficiencies and other health problems can exist alongside menopause and deserve to be identified and treated.
You can explore more articles, free and paid resources, my book and programmes in the Hormones and Menopause section of Feel Good Menopause.
