The AMH test measures anti-Müllerian hormone, a protein produced by the granulosa cells of small ovarian follicles and used as a marker of ovarian reserve. Its concentration in blood is proportional to the number of follicles still in reserve, so it estimates how many eggs remain available and how many can be expected from a stimulation cycle. The blood sample can be taken on any day of the cycle. Variability is greater with normal or high AMH and minimal when AMH is low. It is always read alongside your age and your antral follicle count.
What an AMH test measures
Anti-Müllerian hormone is produced by the granulosa cells surrounding preantral and small antral follicles, those under 8 millimetres. Once a follicle grows and starts depending on FSH to mature further, it stops producing it. That is why the blood level reflects the size of the pool of follicles waiting, not the follicle growing in that particular cycle.
With automated assays, variability of around 20 % within a cycle and up to 28 % between cycles has been observed, mainly with normal or high levels. When AMH is low, variability is minimal and measurement is reliable at any point in the cycle. AMH changes earlier than baseline FSH or oestradiol when reserve begins to fall.
What an AMH test estimates is quantity. There are three things it does not tell you:
- Egg quality. The proportion of eggs with a correct chromosomal complement depends mainly on age, and no blood test measures it directly. A high result at 42 does not change the chromosomal outlook for that age.
- Your chance of conceiving naturally. The practice committee of the American Society for Reproductive Medicine (ASRM) advises against using it to screen fertility in women with no diagnosed reproductive problem, because in the general population it does not reliably separate who will conceive from who will not.
- When you will reach menopause. There is a correlation at population level, but it cannot predict the year for an individual woman.
When to take an AMH test and how to prepare
What is requested as an AMH test, an AMH blood test or an anti-Müllerian hormone test is always the same thing: a venous blood sample, like any other hormone test.
- Day of the cycle: any. This is what sets it apart from FSH and oestradiol, which have to be taken in the first days of the cycle.
- Preparation: none. You do not need to fast or change your routine.
- Result: available within a few days, depending on the laboratory.
AMH levels by age
UK laboratories report AMH in pmol/L. Results from Spain and the United States usually arrive in ng/mL, so both are given below. The conversion is 1 ng/mL ≈ 7.14 pmol/L, and the other way round, 1 pmol/L ≈ 0.14 ng/mL.
The figures that follow are population medians, not limits of normality. Individual spread is wide: at any age there are women with double the median and women well below it whose ovaries respond perfectly well. Each laboratory also publishes its own ranges depending on the assay it uses, so the reference that matters when reading a report is the one printed on that report.
Approximate AMH levels by age:
- Up to 24: around 28 pmol/L (about 4 ng/mL).
- 25 to 29: around 21 pmol/L (about 3 ng/mL).
- 30 to 32: around 18 pmol/L (about 2.5 ng/mL).
- 33 to 34: around 14 pmol/L (about 2 ng/mL).
- 35 to 37: around 11 pmol/L (about 1.5 ng/mL).
- 38 to 39: around 7 pmol/L (about 1 ng/mL).
- 40 to 41: around 5 pmol/L (about 0.7 ng/mL).
- 42 to 44: around 3 pmol/L (about 0.4 ng/mL).
- 45 and over: below 2 pmol/L (under 0.3 ng/mL).
The curve is not a straight line. Between 25 and 33 the decline is slow, from 35 it accelerates, and from 40 onwards values cluster at the bottom of the scale. A result above the median for your bracket does not bring motherhood forward, and one below it does not close options: it sets the starting point for planning.
Alongside the age reading, laboratories and guidelines use a cross-sectional one:
- High: above 25 pmol/L (3.5 ng/mL).
- Normal: between 7 and 25 pmol/L (1 to 3.5 ng/mL).
- Reduced: below 7 pmol/L (1 ng/mL).
- Very reduced: below 3.5 pmol/L (0.5 ng/mL).
The two readings combine. A result of 8.5 pmol/L at 41 sits above what is expected for that age; the same 8.5 at 28 sits clearly below.
What is a good AMH level to get pregnant?
There is no threshold that grants or rules out a pregnancy, and this is the question that brings most people to an AMH result in the first place.
AMH estimates how many eggs remain, not whether conception will happen this month. Women with very low levels conceive naturally, and women with normal levels can struggle for entirely different reasons: tubal factor, sperm quality, endometrial receptivity or age-related egg quality. The number is useful for planning timing and medication doses, not for making an individual forecast.
Where AMH does change the conversation is in treatment. It anticipates how many mature eggs a stimulation cycle is likely to yield, and therefore how many cycles may be needed to reach a given goal.
Low AMH: what it means and what it doesn’t
A low AMH result means fewer follicles remain than expected for your age, and that a stimulation cycle will probably yield fewer eggs.
It is not the same as infertility, and it is not a sign that menopause is close. It speaks about quantity, not about your ability to ovulate or about the quality of what remains. Many women with reduced AMH ovulate normally, with regular cycles. It is also distinct from premature ovarian insufficiency, which is a separate condition with its own diagnostic criteria.
A low result at a young age is one of the main reasons to consider egg freezing without letting time pass.
High AMH and PCOS
A high AMH result often accompanies polycystic ovary syndrome, where the ovary accumulates many small antral follicles producing the hormone without any of them going on to ovulate.
In that context it anticipates an intense response to ovarian stimulation, so the dose is adjusted downwards to contain the risk of ovarian hyperstimulation syndrome. A high result on its own, without an ultrasound scan and a compatible clinical picture, does not diagnose polycystic ovaries.
Can you increase your AMH levels?
No. The follicles that produce it do not regenerate, and no supplement or treatment recovers those already lost. This matters because it is one of the most heavily marketed claims in fertility, and it is not true.
Three separate things are often confused with raising AMH:
- Recovery after hormonal contraception changes the measured value, not the reserve itself. AMH, antral follicle count and ovarian volume recover 3–6 months after stopping hormonal contraception. This does not mean you should stop contraception to have the test: tell your clinician so the result can be interpreted in context.
- Adjusting the stimulation protocol can improve how many eggs are retrieved from the reserve you have. It changes the outcome of the cycle, not the reserve.
What can distort your result
An AMH value can only be read clinically if the context in which it was taken is known:
- Hormonal contraception. It lowers the value reversibly, typically by 20 to 30 %, and can lead to reserve being underestimated. AMH, antral follicle count and ovarian volume recover 3–6 months after stopping hormonal contraception. This does not mean you should stop contraception to have the test: tell your clinician so the result can be interpreted in context.
- Laboratory assay and units. Automated platforms have improved reproducibility, but differences between assays remain. And the same value looks seven times different depending on whether it arrives in pmol/L or ng/mL.
- Disagreement with the follicle count. Interpret the result alongside age, the follicle count and clinical history. If results disagree or are close to a threshold that could change treatment, repeating the test may be prudent. Antral follicle counts are covered in the guide on how many follicles are normal.
- Recent chemotherapy or ovarian surgery. Both lower the value, temporarily or permanently depending on the case, and a test taken in the months afterwards does not reflect the settled situation.
How much does an AMH test cost in the UK?
AMH testing is available through some NHS fertility services. Whether it is appropriate and available in your case depends on the assessment and local service criteria; ask your GP or fertility clinic about the pathway in your area.
Privately there are two different routes, and the price gap between them reflects what you get:
- A laboratory or postal test kit returns a number and a reference range.
- A fertility consultation returns an interpretation. An AMH value without an ultrasound scan, without your age and without your clinical history is an incomplete piece of information, and it is the source of a good deal of the anxiety people arrive with.
In a fertility test the AMH is requested together with the scan and the appointment where the result is read, which is what turns a number into a decision.
Frequently asked questions about the AMH test
What is a normal AMH level at 40?
Approximately 5 pmol/L, or about 0.7 ng/mL. It is a population median with wide spread: at that age there are women above 11 pmol/L and women below 2. The value is read alongside the ultrasound scan and your clinical history.
Can you increase your AMH levels?
No. The follicles that produce it do not regenerate and no supplement recovers those already lost. AMH, antral follicle count and ovarian volume recover 3–6 months after stopping hormonal contraception; this changes the measured result, not the reserve. It is not a recommendation to stop contraception for testing. Adjusting the stimulation protocol can improve the response without restoring lost follicles.
What is a good AMH level to get pregnant?
There is no cut-off that grants or rules out pregnancy. AMH estimates how many eggs remain, not whether conception will happen. It is used to plan doses and timing, not to forecast an individual outcome.
When in my cycle should I have an AMH test?
At any point. Variability is greater with normal or high AMH and minimal when AMH is low. The result is read alongside age and the antral follicle count. You do not need to fast.
Is a high AMH result a problem?
Not in itself. It indicates many small follicles available and is often associated with polycystic ovary syndrome. What changes is the management: it anticipates an intense response to stimulation and calls for a lower dose to reduce the risk of hyperstimulation.
Do men have anti-Müllerian hormone?
Yes. The Sertoli cells of the testicle produce it, and during foetal development it is responsible for the Müllerian ducts not forming. In adults it is used mainly to assess testicular function in specific cases, and its reference values are different.
Can my AMH result change from one test to another?
Yes, and it does not always mean your reserve has fallen. Variability is greater with normal or high AMH and minimal when it is low; the assay and medication also matter. Interpret the result with the follicle count and clinical history. If results disagree or lie close to a threshold relevant to treatment, repeating the test, preferably at the same laboratory, may be prudent.
