by Dr Kate Burns, ⊕ medically reviewed by Dr Rebecca Tomlinson on 10th October, 2022
For many women, working out whether or not you’re in perimenopause or menopause can feel like a bit of a guessing game, especially if you are taking hormonal contraception, which can mask or cause one of the key signs of perimenopause and menopause – your periods becoming irregular or absent. One option for women looking to understand where they are in their menopause journey is the use of a hormonal blood test, which can take a measure of your hormone levels to determine if you are in menopause. Hormonal blood tests work by measuring your hormone levels to work out whether or not you are menopausal. Menopause specialist GP, Dr Kate Burns, explains everything you need to know about blood tests, including how they work, when you should use them, how to read menopause blood test results, and how they can help.
Can a blood test help to diagnose menopause?
Yes, in certain circumstances – but their reliability depends on your age and several other factors. More on this will be explained below, but first, it’s important to understand that hormonal blood tests work by measuring the hormone levels in your blood. When you are in menopause or post-menopause, the hormonal changes expected to be found in your blood are low levels of the sex hormone estradiol (oestrogen) and raised levels of the gonadotrophin hormones FSH (Follicle Stimulating Hormone) and LH (Luteinizing Hormone), which control the functioning of the ovaries. When the ovaries start to fail, FSH and LH levels increase in an attempt to keep the ovaries going. If a blood test confirms raised menopause-range FSH levels, it can be a good indication that you are undergoing menopause. However, it is not clear cut! A test indicating raised, menopausal-range FSH levels should be repeated in 6 weeks to confirm that you are in menopause. In contrast, a normal, non-menopausal range FSH level does not rule out menopause.
How to understand menopause blood test results
As explained above, test results can be confusing to interpret, but the cut off points for FSH levels are relatively straightforward. A general guide is that a blood FSH level of >30 IU/L (some laboratories suggest above 26IU/L) suggests that the ovaries are slowing down, and can be taken as a potential indicator of menopause.
Can a blood test check what stage of menopause you have reached?
The simple answer is, not necessarily. However, a general rule is that FSH levels may be either normal or raised in perimenopause; but will be raised at the postmenopausal stage.
When are menopause hormone blood tests recommended?
Generally, checking blood hormone levels is neither necessary nor helpful for women aged 45 or older. This is because:
- At or beyond 45, we can advise based on your age and typical menopausal symptoms (and/or typical period changes) that your symptoms are related to menopause.
- A blood test that records normal hormone levels does not mean that you are not experiencing perimenopause. This is because when some ovary function remains, as is common in perimenopause, hormone levels will vary at different times and may well remain within the normal range (GPN).
- Hormonal levels within the menopausal range do not mean that pregnancy is no longer possible, as ovulation (egg release from the ovaries) may still occur.
- If you are using hormonal contraception (or HRT, Hormone Replacement Therapy), this may make hormonal levels unreliable.
- Bloods tests for premature menopause: under the age of 45
Under the age of 45, though the same problems of hormone levels potentially being normal during perimenopause still apply, blood hormone levels are worth checking as experiencing menopause at this age is classed as early and is managed slightly differently. Hormonal checks must be carried out if you are under 40 and experiencing period changes or symptoms suggestive of menopause. This is because medical professionals need them to detect a condition called premature ovarian insufficiency (POI), or “premature” menopause, and thus be able to provide you with the correct care.
Can you use hormonal blood tests to work out whether or not you can safely stop contraception?
Potentially, yes. This depends on both your age and the contraception you are using, and whether or not you’re using HRT. If your GP thinks hormonal blood tests are helpful and relevant, it is important to remember that the use of either HRT or certain hormonal contraception may well impact the reliability of the blood test results. If you’re using HRT or combined hormonal contraception (CHC), i.e. the combined pill, vaginal ring, or patch, then hormonal blood tests will not give you a reliable result. These hormones suppress your body’s levels of FSH and LH. Blood tests work by measuring these exact hormones, so if you are taking medication that affects them, testing cannot tell you accurately where you are in terms of your menopause, or whether or not you can stop contraception. If you’re using progestogen-only contraception (progestogen-only pill, implant, depo injection, and hormonal coils) blood testing can be reliable. Your FSH levels are not affected by these methods of contraception. As such, if you are not experiencing a period and you are over fifty, and if you are using progestogen-only contraception, blood testing can determine whether or not you need to use contraception. However, if you are under fifty, blood testing this way cannot tell you whether you can stop using contraception. Here is everything you need to know about menopause contraception.
Menopause blood test – key facts
- Hormonal blood tests are used to work out the presence and level of menopausal hormones in your blood. However, their use and efficacy both depend on your age and your use of contraception and/or HRT.
- For women aged 45 or above with typical menopausal symptoms and/or typical period changes, hormonal blood tests are not recommended nor needed. We can make an accurate guess due to your age and symptoms that you are most likely perimenopausal or menopausal. Blood tests at this age may be misleading and not give you an accurate representation of where you are in your menopausal journey.
- Hormonal blood tests are generally recommended for women under 45 with potential menopausal symptoms and/or relevant period changes. However, the results may still not give you a clear answer.
- For women aged 50 or above who are not experiencing periods, blood hormone (FSH) levels may be useful when deciding whether or not contraception can be safely stopped. However, it is important to remember that if you are using either HRT or combined hormonal contraception, the tests will not reflect accurate results.
- For women not using any hormones, contraception can be safely stopped two years after your last menstrual period if you are under 50. If you are over 50, you are safe to stop contraception one year after your last menstrual period.
- All women over 55 years can safely stop contraception, no blood tests are needed, as pregnancy is extremely rare at and after this age.
