AMH Blood Test UK: Understanding Your Ovarian Reserve

The AMH blood test has become widely available in the UK. Search for it and you get a mix of clinic sales pages, forum threads and conflicting numbers, and not much that actually explains what your result means. This is a plain guide to what an AMH test measures, how it is interpreted by age and testing method, and what a high or low result does and does not tell you.

Key points

• AMH (anti-Müllerian hormone) is an indirect marker of your ovarian reserve, the size of your remaining follicle pool. It reflects egg quantity, not egg quality.

• There is no single normal AMH value. Levels fall with age, so your result only makes sense when read against your age.

• A low AMH does not reliably predict whether you will conceive naturally, and many women with low levels still get pregnant.

• A high AMH is often seen in polycystic ovary syndrome (PCOS).

• AMH is used mainly to plan fertility treatment, such as predicting how the ovaries will respond to IVF.

• AMH can usually be measured on any day of the cycle and does not require fasting. Other fertility hormones in a wider panel, such as FSH, LH and oestradiol, may need to be timed to your cycle.

What is AMH?

Anti-Müllerian hormone is made by the small, developing follicles in your ovaries. Each follicle holds an immature egg. The more of these small follicles you have, the more AMH shows up in your blood. So an AMH level gives an indirect estimate of the number of small developing follicles in your ovaries, which is what doctors mean by your ovarian reserve. It does not count the total number of eggs you have left.

You are born with all the eggs you will ever have, and that number falls throughout life. AMH follows the same path. It rises through childhood, peaks at around age 25, then declines steadily toward the menopause. That decline is the single most important thing to understand about your result. A number that looks low for a 25-year-old can be completely expected at 40.

What an AMH test can and cannot tell you

This is where a lot of the worry comes from, so it is worth being clear.

AMH tells you roughly how many small follicles you have. It does not tell you how good the eggs inside them are. Egg quality matters more than egg number for a healthy pregnancy, and there is no blood test for it. Age is still the best guide to egg quality.

AMH is also a poor predictor of whether you will conceive naturally, and it is not a reliable standalone fertility test. Current UK guidance is clear that AMH should not be used to predict your chance of a spontaneous pregnancy. One large study of women aged 30 to 44 with no history of fertility problems found that those with low ovarian reserve markers were no less likely to conceive than women with normal levels. A more recent cohort of more than 3,000 women found a modest effect: a low AMH was linked to a slightly lower chance of conceiving in a given month, but plenty of women with low levels still became pregnant. The honest summary is that a low AMH may nudge the odds, it does not close the door.

So what is it good for? Planning. If you are considering IVF or egg freezing, AMH helps a specialist predict how your ovaries are likely to respond to stimulation, in plain terms, roughly how many eggs might be collected in an IVF cycle. AMH is much better at predicting that response than at predicting whether you will conceive naturally.

AMH levels by age: what is a normal or good level?

UK laboratories report AMH in picomoles per litre (pmol/L). Some clinics and older charts use nanograms per millilitre (ng/mL). To convert, multiply the ng/mL figure by 7.14 to get pmol/L.

Here is the honest answer: AMH usually declines with age, but there is no single age-based normal range. The same sample can read differently between laboratories, because assay platforms and reference populations vary and there is still no international standard for the test. So online charts should be treated cautiously. Your result should be interpreted using the laboratory's assay-specific information, together with your age, contraceptive use, menstrual history and the reason the test was requested. A laboratory reference range is not a pass or fail measure of fertility.

What the numbers do show is a clear downward trend. AMH is at its highest in your twenties and falls through your thirties and forties toward the menopause. A result that would look low at 25 can be entirely normal at 40, which is why age has to be part of the interpretation.

For fertility treatment, current UK guidance does not set one universal AMH cut-off for a low or high response. NICE recommends using AMH, or an antral follicle count, to help predict ovarian response and to support counselling about assisted conception, and it advises against using FSH for this purpose. The result needs to be interpreted using the laboratory's assay and the fertility clinic's own validated approach.

What does a low AMH result mean?

A low AMH usually suggests that fewer small follicles are available to respond to ovarian stimulation than would be expected for your age, though contraception, laboratory method and individual variation can all affect the result. It may be relevant if you are considering IVF or egg freezing, because it helps predict the likely response to stimulation. It should not be used as a countdown of your remaining fertile years, or as a standalone reason to bring forward or delay a pregnancy. And it is not the alarm bell it is often treated as.

Low AMH does not reliably predict whether you will conceive naturally. It says nothing about the quality of the eggs you do have. Some studies find no link with natural fertility at all, and even where a link does show up it is modest, with many women who have a low reading going on to conceive. Where it matters most is treatment planning. A lower AMH may predict that fewer eggs will be collected after ovarian stimulation, but it does not determine whether natural conception is possible, or whether any individual egg is healthy.

If you are trying to conceive and it is not happening, a low AMH is one piece of a bigger picture that also includes your age, your cycle, your partner, and other tests. It is a reason to seek proper advice, not a reason to panic.

What does a high AMH result mean?

A high AMH usually reflects a large number of small follicles, and one common explanation is polycystic ovary syndrome. Women with PCOS tend to have higher AMH levels because their ovaries carry more small follicles than usual.

Under the 2023 international PCOS guideline, a raised AMH can be used in adults as an alternative to an ultrasound scan to identify polycystic ovarian morphology (the polycystic-looking ovaries seen in PCOS), though it is only one part of a diagnosis that also depends on your symptoms and other tests. A high AMH on its own does not diagnose PCOS. It is most helpful when the diagnosis is uncertain, rather than when irregular cycles and signs of excess androgens already point to it, and it is not used this way in teenagers, whose levels are naturally higher.

Can you increase your AMH?

Your AMH reflects the pool of follicles your ovaries currently hold, and that pool shrinks with age rather than being rebuilt. There is no supplement or lifestyle change proven to raise your underlying ovarian reserve, and it is worth being wary of products that promise to.

One thing genuinely can lower your reading without changing your true reserve: hormonal contraception, most clearly the combined pill. Women currently using the combined contraceptive pill have AMH levels around 30 percent lower than non-users. The effect is temporary. When women stop the combined pill, AMH rises again and tends to settle back around its baseline within about two months. The size of the effect varies between methods and individuals, so a result taken while you are using hormonal contraception should be read with caution, and it is worth telling the doctor interpreting your test.

Can you get an AMH test on the NHS?

AMH may be arranged as part of a specialist fertility assessment, or when planning fertility treatment. Whether it is offered, and at what stage, varies between local NHS pathways.

Private AMH testing is also available. It can be useful if you are considering assisted conception or egg freezing, but it is not a complete fertility assessment and should not be used to predict whether you will conceive naturally. If you have been trying unsuccessfully to conceive, have irregular or absent periods, or have another reason for concern, seek a clinical assessment rather than relying on AMH alone.

When to see your GP

Some situations need clinical assessment rather than a private test on its own:

• If you are under 36 and have not conceived after 12 months of regular unprotected sex, ask your GP for a fertility assessment. If you are 36 or over, or either partner has a known or suspected factor affecting fertility, NICE recommends earlier specialist referral rather than waiting a year.

• If your periods have become very irregular, have stopped, or you have other symptoms that worry you, see your GP so the cause can be looked into properly.

• If you are under 18, fertility hormone testing is interpreted differently and needs specialist input.

Common questions about the AMH blood test

When in my cycle should I have the test?

AMH itself can usually be measured on any day of the cycle. It varies only a little across the month, unlike most other reproductive hormones. If your test also includes FSH, LH and oestradiol, those hormones are affected by cycle timing and are usually interpreted as a baseline profile when measured early in the cycle, commonly between days 2 and 5. Different timing may be right if your periods are absent or irregular, so follow the instructions supplied with your test.

Do I need to fast?

No. Eating beforehand does not affect an AMH result, so there is no need to fast.

Does the pill affect my AMH?

Yes. The combined contraceptive pill, taken currently or recently, lowers your measured AMH, and the level recovers after you stop, usually within about two months. Mention it to whoever interprets your result.

Can AMH predict when I will reach menopause?

AMH is associated with the timing of menopause across a population, but it cannot predict an individual's menopause age accurately enough for routine use, so it cannot give you a reliable date.

Does a low AMH mean I am infertile?

No. It reflects egg quantity, not quality, and does not reliably predict your chance of conceiving naturally, though it may modestly shift the odds. It is useful for planning, not a diagnosis of infertility.

Testing your AMH with Brooksby Medical

If you decide to check your own levels, our Ovarian Reserve and Fertility Hormones Blood Test measures AMH alongside FSH, LH and oestradiol. FSH, LH and oestradiol give information about pituitary and ovarian hormone function rather than three more measures of egg quantity, and they may need to be read according to the day of your cycle. AMH is most useful when interpreted alongside your age, menstrual history, contraceptive use and the reason for testing, so results come with a written report from a practising GP, and the option of a one-to-one consultation with Dr Coleman if you would like to discuss them.

References

1. Kelsey TW, Wright P, Nelson SM, Anderson RA, Wallace WHB. A validated model of serum anti-Müllerian hormone from conception to menopause. PLoS One. 2011;6(7):e22024. doi:10.1371/journal.pone.0022024

2. Steiner AZ, Pritchard D, Stanczyk FZ, et al. Association between biomarkers of ovarian reserve and infertility among older women of reproductive age. JAMA. 2017;318(14):1367-1376. doi:10.1001/jama.2017.14588

3. American College of Obstetricians and Gynecologists. The use of antimüllerian hormone in women not seeking fertility care. Committee Opinion No. 773. Obstet Gynecol. 2019;133(4):e274-e278. doi:10.1097/AOG.0000000000003162

4. Nelson SM, Davis SR, Kalantaridou S, et al. Anti-Müllerian hormone levels are associated with time to pregnancy in a cohort study of 3,150 women. Fertil Steril. 2024;122(6):1114-1123. doi:10.1016/j.fertnstert.2024.06.024

5. National Institute for Health and Care Excellence. Fertility problems: assessment and treatment. NICE guideline NG257. Published 31 March 2026. nice.org.uk/guidance/ng257

6. Teede HJ, Tay CT, Laven JJE, et al. Recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome. Hum Reprod. 2023;38(9):1655-1679. doi:10.1093/humrep/dead156

7. Cedars MI. Evaluation of female fertility: AMH and ovarian reserve testing. J Clin Endocrinol Metab. 2022;107(6):1510-1519. doi:10.1210/clinem/dgac039

8. Bentzen JG, Forman JL, Pinborg A, et al. Ovarian reserve parameters: a comparison between users and non-users of hormonal contraception. Reprod Biomed Online. 2012;25(6):612-619. doi:10.1016/j.rbmo.2012.09.001

9. Landersøe SK, Birch Petersen K, Sørensen AL, et al. Ovarian reserve markers after discontinuing long-term use of combined oral contraceptives. Reprod Biomed Online. 2020;40(1):176-186. PMID:31831368

10. van Disseldorp J, Lambalk CB, Kwee J, et al. Comparison of inter- and intra-cycle variability of anti-Müllerian hormone and antral follicle counts. Hum Reprod. 2010;25(1):221-227. doi:10.1093/humrep/dep366

11. Depmann M, Eijkemans MJC, Broer SL, et al. Does anti-Müllerian hormone predict menopause in the general population? Results of a prospective ongoing cohort study. Hum Reprod. 2016;31(7):1579-1587. doi:10.1093/humrep/dew112

Written by Dr James Coleman, GP and founder of Brooksby Medical. Dr Coleman is a practising General Practitioner (GMC 7149224) who founded Brooksby Medical to give patients direct access to the blood tests and clinical interpretation they need, without long waits.

Medically reviewed: July 2026 | Next review due: July 2027

AMH is useful for estimating how your ovaries may respond during fertility treatment, but it measures egg quantity, not egg quality, and cannot on its own reliably tell you whether you will conceive naturally or when you will reach menopause.