Diagnosing menopause · blood tests
The UK's NICE guideline says that in a healthy woman aged 45 or over with typical symptoms, perimenopause and menopause should be recognised without laboratory tests. On hormonal contraception or after a hysterectomy the calendar doesn't work, and the diagnosis rests on symptoms. The SWAN study shows what a test would catch: the hormone FSH starts rising about six years before the last period and settles only two years after it. A single blood draw catches one day of a curve that is still moving.
What each test says
The same tests play different roles at different ages. The answers below are the guidelines', for age groups, not for any one person.
The FSH curve
The SWAN study took blood once a year from 1,215 women whose last period was documented. On average, FSH began rising 6.1 years before the last period, sped up two years before and levelled off two years after. Oestradiol, on average, stayed unchanged until two years before. In women with obesity, the rise began later, 5.45 years before.
Same woman, different cycles
A Swedish study followed 13 women with blood samples three times a week, for four weeks a year, over four to nine years. Prolonged or anovulatory cycles with high FSH appeared only in the last 27 cycles and made up 62% of the last ten. The ovulatory cycles of the same women looked hormonally the same as they had for years.
Why a “normal” result doesn't reassure
In a study of daily urine samples from 156 women, a woman's FSH level could not be told apart from reproductive-age levels until after the rapid perimenopausal rise. After 45, NICE relies on symptoms and the cycle.
Under 40
Menopause before 40 is called premature ovarian insufficiency. Here the FSH test is part of the diagnosis, and the guidelines differ. NICE, in 2015, asks for symptoms, absent or infrequent periods and raised FSH in two samples taken 4–6 weeks apart, and rules out diagnosis on a single test. ESHRE, the European Society of Human Reproduction and Embryology, has since 2024 accepted a single value above 25 IU/l, alongside at least four months of absent or irregular cycles; a second sample is taken only if the diagnosis is uncertain.
ESHRE also notes that premature ovarian insufficiency without an external medical cause is not rare: about 1% of women in older studies, 3.5% in recent ones. It recommends excluding pregnancy and measuring TSH, the hormone that reflects thyroid function. AMH can help as a supporting test when FSH is inconclusive.
Contraception and other treatments
NICE recommends not using FSH to identify menopause in people taking combined oestrogen and progestogen contraception or high-dose progestogen. ESHRE warns that hormonal treatments can hide or cause irregular cycles and may lower FSH, and bleeds on the pill are not natural periods. Likewise, hormonal treatments for heavy bleeding can hide the pattern of the cycle.
That means the 12-month rule cannot be applied on hormonal contraception. When to stop it is a conversation with the doctor; pregnancy is still possible in perimenopause.
Before you pay
Private laboratories in Romania sell test packages labelled for perimenopause or menopause. One such package, at an offer price of 410 lei (about €80) in September 2026, contained FSH, LH, oestradiol, TSH, FT4, a full blood count, vitamin B12, vitamin D, calcium and magnesium. Some of these can be useful for other reasons, such as the thyroid or anaemia. To establish whether you have reached menopause after 45, NICE asks for none of them.
“Am I in menopause?” has a different answer from “why am I tired?” or “is my thyroid all right?”. Ask for each test to have a question.
On combined contraception or high-dose progestogen, FSH cannot confirm menopause.
After 45, with typical symptoms, treating the symptoms does not wait for a test. If the result would not change the decision, it may not be needed.
Sources
Sources rechecked 27 September 2026 · No independent clinical review · Not a substitute for a consultation