If you've ever asked for a blood test "to see if I'm in perimenopause" and been told the test isn't useful, this is why. FSH and LH aren't the hormones that make you feel anything — they're the brain's signal asking the ovaries to ovulate, and they swing wildly through perimenopause. A single number on a single day rarely tells you what your symptoms, your cycle pattern and your age can already tell a menopause-trained doctor. The test does become genuinely useful in a few specific situations, which the page below walks through.
What it does
Follicle-stimulating hormone (FSH) and luteinising hormone (LH) come from the pituitary gland in your brain, not the ovaries. They're the messages the brain sends DOWN to ask the ovaries to ovulate. As ovaries get less responsive, the brain shouts louder — which is why FSH rises in perimenopause and stays high in menopause.
What changes in perimenopause
FSH levels swing wildly through perimenopause, sometimes high, sometimes back to a 'reproductive' range within weeks. A single 'normal' FSH does NOT rule out perimenopause. A single 'high' FSH doesn't confirm it either. This is why most menopause societies recommend diagnosing perimenopause from your symptoms and your age, not from a one-off blood test.
Where you'll feel it
You don't, directly. You feel the consequences (the estrogen and progesterone swings these hormones drive). FSH/LH matter mainly when investigating premature menopause (under 40), unusual presentations, or to monitor very specific treatments.
What the appointment language sounds like
If a doctor offers a single FSH test to 'check if you're in menopause' and you're between 45 and 55 with the symptoms, the guideline answer in most countries is that the test isn't needed. Under 40, or with surgery or chemotherapy in the picture, the test is more useful and may be repeated.
Why a single FSH test is so often misleading
The lab number you've probably been quoted
FSH rises in perimenopause because the ovaries become less responsive — the brain has to shout louder to get a follicle to mature. The catch is that perimenopausal FSH swings: it can be 'menopausal' one week and 'reproductive' three weeks later, depending on where you are in a cycle that may itself be irregular. A single high reading does not confirm menopause; a single normal reading does not rule out perimenopause.
This is why every major guideline (NICE, NAMS, IMS, BMS) recommends diagnosing perimenopause from age and symptoms in women between 45 and 55, not from a one-off FSH. The test mainly earns its keep in three situations: suspected premature ovarian insufficiency (under 40), unusual presentations, and monitoring after specific treatments.
When the test is genuinely useful
Premature ovarian insufficiency, surgical menopause, and the cancer-treatment context
Under 40 with absent or very irregular periods plus menopausal symptoms is the textbook indication: two FSH levels at least 4 to 6 weeks apart, both elevated, supports a diagnosis of premature ovarian insufficiency (POI). POI is not the same as 'early menopause' — it has implications for fertility, bone, cardiovascular and brain health that need a specialist plan, not reassurance.
FSH and LH also have a role in monitoring after chemotherapy- or radiation-induced ovarian shutdown, after some forms of GnRH-agonist treatment, and in people on testosterone-blocking therapy. In these contexts the numbers tell a real story; in the routine 'am I in perimenopause' context they usually don't.
AMH and the 'ovarian reserve' question
Useful for fertility, much less useful for menopause timing
Anti-Müllerian hormone (AMH) is sometimes folded into the same conversation. It correlates better with ovarian reserve than FSH and is widely used in fertility clinics. For predicting how soon you will reach menopause, AMH is better than nothing but is still imprecise — typically able to suggest 'within a few years' rather than a date. It does not replace the symptom-and-age conversation.
Tests you'll see marketed — DUTCH and 'adrenal fatigue'
Why the panels in your Instagram feed aren't doing what the marketing says
Two tests come up constantly in perimenopause wellness marketing: the DUTCH panel (Dried Urine Test for Comprehensive Hormones), and salivary cortisol panels sold as a way to diagnose 'adrenal fatigue'. Both promise a level of precision that the underlying science doesn't actually support, and both are usually sold alongside a supplement protocol or compounded prescription the same practitioner stands to benefit from.
DUTCH measures urinary metabolites of estrogen, progesterone, androgens and cortisol over a 24-hour collection. It's a legitimate research tool. The problem is that population reference ranges for most of those metabolites aren't standardised across labs, the correlation with serum or tissue hormone activity in a symptomatic perimenopausal woman is weak, and no major menopause or endocrine society — NAMS, IMS, BMS, Endocrine Society — recommends DUTCH as a basis for diagnosing perimenopause or choosing an HRT dose. A normal-feeling result doesn't rule perimenopause out; an abnormal-looking result doesn't tell you what dose of estradiol you need.
'Adrenal fatigue' is the bigger one. It's not a recognised medical diagnosis. The Endocrine Society has been explicit, in plain language, that there is no scientific evidence that long-term stress causes the adrenal glands to 'wear out' and under-produce cortisol in the way the marketing describes. Salivary cortisol panels can be useful in suspected Cushing's syndrome or adrenal insufficiency (Addison's), which are real, named, treatable conditions worth ruling out — but four-point salivary cortisol curves are not a validated way to diagnose stress-related exhaustion, and the supplements typically sold off the back of them (adrenal glandulars, high-dose licorice, unregulated 'cortisol manager' blends) have their own real risks.
Here's the part that matters: the exhaustion is real. Perimenopausal fatigue is one of the most consistent symptoms in every longitudinal cohort study of the transition, and it has plausible mechanisms — disrupted sleep, fluctuating estrogen and progesterone, mood load, often ADHD that has finally lost its hormonal scaffolding. The symptom deserves a serious workup. The fix usually isn't a urine panel or an adrenal supplement — it's checking thyroid, ferritin, B12, vitamin D, sleep quality, mood, and whether HRT is on the table. If a practitioner is leading with DUTCH or an 'adrenal stress index', a fair question is: what will you do differently based on the result, and is that thing supported by guidelines.
The evidence behind this page
What the studies and guidelines actually say
Curated, primary-source-or-guideline only. Each card opens the original paper or position statement so you can read it for yourself.
Diagnose perimenopause and menopause in women aged over 45 from symptoms alone; do not routinely use FSH to diagnose menopause in this group.
The most-cited statement in modern menopause primary-care guidance.
Read the sourceSingle FSH measurements show high within-woman variability across the menopause transition; serial measurements weeks apart are more informative.
Hall et al · Study of Women's Health Across the Nation
Read the sourcePremature ovarian insufficiency is diagnosed by two elevated FSH levels at least 4–6 weeks apart in women under 40 with menstrual disturbance and menopausal symptoms.
POI carries fertility, cardiovascular and bone implications that go beyond a 'low FSH = menopause' framing.
Read the sourceAMH offers a modest improvement over FSH in predicting time to menopause but is not precise enough to give a date.
'Adrenal fatigue' is not a recognised medical diagnosis; there is no scientific evidence that long-term stress causes the adrenal glands to under-produce cortisol in the manner described in popular wellness literature, and salivary cortisol panels are not a validated diagnostic for it.
Plain-English statement from the international endocrinology society. Useful to read before paying for a four-point cortisol curve.
Read the sourceA systematic review of 58 studies found no substantiation of 'adrenal fatigue' as a medical condition; cortisol assessment methods varied widely and produced contradictory results.
Cadegiani & Kater
Read the sourceUrinary hormone metabolite panels (including dried-urine formats marketed as DUTCH) are not endorsed by major menopause societies as a basis for diagnosing perimenopause or guiding MHT dosing; symptom-based diagnosis remains the standard of care in women aged 45–55.
Neither NICE nor NAMS lists urinary metabolite panels as a recommended diagnostic. Read alongside the NAMS compounded-BHRT statement, which addresses the related practice of prescribing custom hormones off the back of these results.
Read the sourcePerimenopause stages clinically using STRAW+10: variable cycle length and skipped cycles in late perimenopause, with diagnosis driven by symptom pattern and cycle history rather than a single hormone test.
Santoro N
The plain-clinician summary of STRAW+10 staging that most modern menopause writing leans on. Useful to send a doctor who's still looking for one definitive blood test.
Read the source