Key takeaways
- FSH is the pituitary signal that drives egg development each cycle, and it's most informative when tested on cycle days 2 to 5.
- FSH moves from month to month, so a doctor reads each result alongside your age, cycle pattern and symptoms.
- Over 45, menopause is usually diagnosed from symptoms and period pattern alone; under 45, FSH can be part of a doctor's assessment.
- For a fuller picture, the short Female Hormone Profile adds LH, prolactin and oestradiol, the full Female Hormone Blood Test also adds testosterone and SHBG, and the Fertility Blood Test adds anti-Müllerian hormone (AMH).
- Your laboratory report shows the reference range next to your result.
You've been told to have your FSH checked on day 3 of your cycle, or it came up while you were reading about fertility or the menopause. Now you want to know what the number will actually tell you.
FSH, or follicle stimulating hormone, is made by the pituitary gland and signals the ovaries to develop an egg each cycle. It helps assess fertility and, alongside other markers, the approach to menopause. Book an FSH blood test to check your level, ideally on the cycle day your clinician has advised.
Book an FSH blood test at 117a Harley Street: £71.25 plus the £50 blood draw, results in 1 day.
When in my cycle should I take an FSH test?
FSH is most useful when tested on cycle days 2 to 5, because that's when it best reflects your ovarian reserve and cycle pattern. You can still test outside that window, but the result is harder to read against typical reference patterns. Count day 1 as the first day of full bleeding. If your periods are irregular or have stopped, ask a doctor when to test.
Why does my FSH level change from month to month?
FSH responds to changing hormone signals between the pituitary gland and the ovaries, so it varies from one cycle to the next and even within a single cycle. A single result is one data point, not a fixed measure of your fertility. That's why a clinician may suggest repeating it or reading it alongside other hormones.
Can FSH tell me if I'm in menopause?
Partly, depending on your age. If you are over 45 and have typical symptoms, NICE advises diagnosing perimenopause and menopause from your symptoms and period pattern, without an FSH test. Levels fluctuate during perimenopause, so a single result gives no clear yes or no.
If you are aged 40 to 45, a doctor may use an FSH test as part of the assessment. Under 40, repeated FSH tests are used to check for premature ovarian insufficiency. FSH is not a reliable guide if you are using combined hormonal contraception or HRT.
| Test | What it includes | Price (plus £50 blood draw) | Turnaround |
|---|---|---|---|
| FSH (standalone) | FSH only | £71.25 | 1 day |
| Female Hormone Profile (short) | FSH, LH, prolactin, oestradiol | £195 | 1 day |
| Female Hormone Blood Test (full) | FSH, LH, prolactin, oestradiol, testosterone, SHBG, Free Androgen Index | £245 | 1 working day |
| Fertility Blood Test | FSH, LH, prolactin, oestradiol, AMH, Free T4, TSH | £395 | 1 working day |
| AMH (standalone) | Anti-Müllerian hormone only | £150 | 1 day |
A single FSH test gives one part of the picture. There are two female hormone profiles. The short Female Hormone Profile adds LH, prolactin and oestradiol. The full Female Hormone Blood Test also adds testosterone and SHBG, with a calculated Free Androgen Index, for a broader hormone map. The Fertility Blood Test adds anti-Müllerian hormone (AMH), which reflects ovarian reserve and, unlike FSH, can be taken at any point in your cycle. You can also book AMH on its own.
What does a high FSH result usually mean?
A higher FSH result can reflect reduced ovarian reserve, and it's one of the patterns sometimes seen as women approach menopause. Your doctor will weigh it against your age, cycle pattern, symptoms and any other hormone results before drawing a conclusion. If you are under 40 and your periods have become irregular or stopped, see a doctor, whatever a single FSH result shows.
What does a low FSH result usually mean?
A lower FSH result can be seen in some causes of irregular or absent periods, including patterns linked to the pituitary gland or hypothalamus rather than the ovaries. As with a high result, it's read alongside your wider clinical picture.
Do I need to fast before an FSH test?
No, you can eat and drink as normal. Timing within your cycle matters more than food, so mention your last period date when you book or attend.
Booking an FSH test
Like all our private blood tests in London, the FSH test can be booked online or as a walk-in at 117a Harley Street, seven days a week. No GP referral is needed. Results usually arrive by email within 1 day, and you can add a doctor review of your report for £75.
If you'd like your result discussed alongside your symptoms and history, a specialist gynaecology consultation at Gynae Clinic can put the number in context. When you're ready, book your FSH blood test or the Fertility Blood Test online. Start your booking.
Frequently asked questions
Is a high FSH always a sign of menopause?
It's one pattern seen as women approach menopause, but FSH fluctuates, so it's read alongside your age, symptoms and period pattern.
Does taking the contraceptive pill affect my FSH result?
Yes. Combined hormonal contraception and some progestogen-only methods suppress FSH, so a result taken while you use them is not a reliable guide to fertility or menopause.
How is FSH different from AMH?
FSH varies with your cycle day and month to month, while AMH reflects ovarian reserve more steadily and can be tested on any day. They are often looked at together for a fuller fertility picture.
Can I test FSH if I'm not trying to conceive?
Yes. FSH also helps investigate irregular periods, amenorrhoea and perimenopausal symptoms.
How quickly will I get my FSH result?
Results for the standalone FSH test are usually available within 1 day by email.
References
- NHS: Menopause
- NICE guideline NG23: Menopause, diagnosis and management
- NHS: Early menopause
- NHS: Infertility
- Lab Tests Online UK: FSH test