Brief Myth-buster
Do you need a blood test to confirm perimenopause?
Usually not. For otherwise healthy people aged 45 or over with menopause symptoms, the UK's NICE guideline says perimenopause can be identified from symptoms and changes in periods, without lab tests1. ACOG, the US ob-gyn society, puts it plainly: "You probably don't need hormone testing"2.
What the guidelines say
NICE, the UK's National Institute for Health and Care Excellence, says that for otherwise healthy people aged 45 or over with menopause symptoms, clinicians should identify the following without lab tests1.
- Perimenopause, if hot flashes or sweats have recently started and your cycle has changed in any way.
- Menopause, if you haven't had a period for at least 12 months and aren't using hormonal contraception.
- Menopause after a hysterectomy, from the type and mix of symptoms you have.
NICE also lists tests not to use to identify perimenopause or menopause at 45 or over: anti-Müllerian hormone (AMH), inhibin A and B, estradiol, antral follicle count and ovarian volume1. ACOG's answer is the same in fewer words. It says your ob-gyn should be able to tell from your age, your symptoms and any changes in your periods2.
Why one blood test can't settle it
Hormones in perimenopause don't drop in a neat line. STRAW+10, the expert system researchers and clinicians use to stage reproductive aging, describes FSH (follicle-stimulating hormone) in the early transition as "elevated but variable." In the late transition it describes "extreme fluctuations in hormonal levels"3. It treats changes in your cycle as the main criteria and hormone tests as supporting evidence only, used when needed and not required for a diagnosis, partly because hormone lab tests still aren't standardized internationally3.
The Study of Women's Health Across the Nation (SWAN) shows how slowly the shift unfolds. Researchers took a yearly blood sample from women who were 42 to 52 when the study began in 1996, and tracked 1,215 of them to a documented natural final period. On average, FSH started rising about 6 years before the final period, climbed faster from about 2 years before, and didn't level off until about 2 years after. Average estradiol held steady until about 2 years before the final period, then fell4. A single blood draw catches one moment in a change that takes years.
When a blood test does come up
- You're under 45 and your periods are changing. ACOG says you may be offered a blood test to check your hormone levels, especially if you're under 40, to see whether you're going through early or premature menopause2. NICE says an FSH blood test can be considered to confirm menopause only in people aged 40 to 45 with menopause symptoms, including a change in their menstrual cycle, or in people under 40 when menopause is suspected1.
- You're under 40. NICE diagnoses premature ovarian insufficiency from symptoms, including no periods or infrequent ones, plus a raised FSH on 2 blood samples taken 4 to 6 weeks apart. It says not to diagnose it from a single blood test1.
- You use hormonal contraception. NICE advises against using an FSH test to identify menopause in people using combined estrogen and progestogen contraception or high-dose progestogen. It also notes that hormonal treatments, for example for heavy periods, can make menopause harder to identify1.
What about home test kits?
The FDA's web page on home menopause tests (content current as of September 27, 2018) says home kits that measure FSH in urine tell you whether your FSH is raised, "not if you definitely are in menopause or perimenopause." It notes that as you get older, FSH can rise and fall during your cycle. A negative result doesn't mean you haven't reached menopause. And the FDA says not to stop using contraception because of a result, since these tests "are not foolproof and you could become pregnant"5.
The limitation
NICE writes guidance for the UK, and US clinicians may follow different practices, so ask what applies to you. ACOG's answer is a short patient Q&A, not a full guideline. The SWAN figures are averages from once-a-year blood samples. They show the overall pattern, not what any one woman's levels will do from month to month4. And all of this is about confirming perimenopause. It doesn't cover blood tests your clinician may order for other reasons.
One thing to try, one thing to ask
For the next three months, note the first day of each period, plus any hot flashes or night sweats, on our printable tracker. STRAW+10 marks the early transition by cycle lengths that keep differing by 7 days or more from one cycle to the next, and the late transition by a stretch of 60 days or more without a period3. Those are the kinds of changes NICE asks clinicians to look at1.
Then ask: "Given my age and my periods, would a hormone test change anything for us? And if you're ordering blood work, what is it checking for?"
Sources
- National Institute for Health and Care Excellence (NICE). Menopause: identification and management (NG23), recommendations 1.3 and 1.7. Published November 2015, last updated April 2026. www.nice.org.uk
- ACOG. Do I need to have testing of my hormone levels during perimenopause? Ask ACOG, published and last reviewed September 2025. www.acog.org
- Harlow SD, Gass M, Hall JE, et al. Executive summary of the Stages of Reproductive Aging Workshop + 10: addressing the unfinished agenda of staging reproductive aging. Menopause, 2012;19(4):387–395. PMID 22343510. doi:10.1097/gme.0b013e31824d8f40. pubmed.ncbi.nlm.nih.gov
- Randolph JF Jr, Zheng H, Sowers MR, et al. Change in follicle-stimulating hormone and estradiol across the menopausal transition: effect of age at the final menstrual period (SWAN). J Clin Endocrinol Metab, 2011;96(3):746–754. PMID 21159842. doi:10.1210/jc.2010-1746. pubmed.ncbi.nlm.nih.gov
- US Food and Drug Administration (FDA). Menopause: home-use tests (FDA web page). Content current as of September 27, 2018. www.fda.gov
Information for better conversations, not a diagnosis. This is research with sources, not medical advice. Talk to your clinician about your situation.