AMH, or anti-Müllerian hormone, is a protein produced by cells in your ovarian follicles that serves as one of the most reliable blood markers of ovarian reserve, essentially how many eggs you have left. Unlike other reproductive hormones, AMH stays relatively stable throughout your menstrual cycle, making it a convenient single blood draw. Your level naturally declines with age, from around 3.0 ng/mL at age 25 to about 0.5 ng/mL by age 45.
What AMH Actually Measures
AMH is produced by the small, growing follicles in your ovaries, specifically the ones that haven’t yet been selected for ovulation in a given cycle. Once a follicle gets large enough to respond to your body’s monthly hormonal signals and become a dominant follicle, it stops producing AMH. So the hormone in your bloodstream reflects the pool of early-stage follicles sitting in reserve, waiting for their turn.
This is why AMH works as a proxy for ovarian reserve. A higher level means more follicles are growing in the background. A lower level means fewer are available. It doesn’t tell you anything about the quality of those eggs, only the quantity.
AMH Levels by Age
AMH peaks in your early twenties and declines steadily from there. Cleveland Clinic provides these lower-end estimates by age:
- Age 25: 3.0 ng/mL
- Age 30: 2.5 ng/mL
- Age 35: 1.5 ng/mL
- Age 40: 1.0 ng/mL
- Age 45: 0.5 ng/mL
These are approximate benchmarks. Individual variation is wide. Two 35-year-olds can have very different AMH levels and both be perfectly fertile. The number is most useful when interpreted alongside your age and other test results, not in isolation.
If your lab report uses pmol/L instead of ng/mL, you can convert by multiplying ng/mL by 7.18. So 1.0 ng/mL equals roughly 7.2 pmol/L.
What a Low AMH Level Means
A low AMH level indicates a smaller pool of remaining follicles, sometimes called diminished ovarian reserve. This doesn’t necessarily mean you can’t get pregnant. It means you likely have fewer eggs available in a given cycle and may respond less robustly to fertility medications if you pursue treatment like IVF.
In fertility treatment, an AMH below about 0.7 ng/mL is associated with a poor ovarian response, meaning fewer than four eggs retrieved during a stimulation cycle. That doesn’t make IVF impossible, but it does change expectations and may influence how your doctor adjusts medication doses.
Very low AMH also offers a rough timeline for menopause. Research published in The Journal of Clinical Endocrinology and Metabolism found that women with AMH below 0.20 ng/mL reached menopause in a median of about six years. For women aged 35 to 39 with that same low level, the timeline stretched to nearly ten years. Once AMH becomes undetectable, menopause follows in roughly six years on average.
What a High AMH Level Means
An unusually high AMH can signal polycystic ovary syndrome (PCOS), a condition where the ovaries contain a large number of small follicles that don’t mature properly. Because each of those follicles produces AMH, the total level in your blood climbs well above the typical range.
Research on diagnostic thresholds suggests AMH above roughly 8.2 ng/mL in women aged 20 to 29, or above 5.9 ng/mL in women aged 30 to 39, raises a strong suspicion of PCOS. These cutoffs correctly identified PCOS in about 78 to 83 percent of confirmed cases. AMH alone doesn’t diagnose the condition, but it’s increasingly used alongside ultrasound and symptom assessment.
In IVF, AMH at or above 3.06 ng/mL predicts a higher-than-average egg retrieval, sometimes exceeding 19 eggs in a single cycle. While that sounds like good news, very high responses carry a risk of ovarian hyperstimulation, so fertility clinics use AMH to calibrate medication doses downward for these patients.
How the Test Works
AMH testing requires a simple blood draw. One of its practical advantages over older ovarian reserve markers like FSH is that it can be done on any day of your menstrual cycle. FSH testing, by contrast, must be done on cycle day 2 or 3 to be interpretable.
That said, AMH isn’t perfectly constant throughout the month. A systematic review found levels run about 11.5% higher during the follicular phase (the first half of your cycle) compared to the luteal phase (after ovulation). This variation is small enough that most clinicians still accept results from any cycle day, but if your result is borderline, the timing of your blood draw could nudge it slightly in one direction.
Factors That Can Skew Your Results
Hormonal contraceptives suppress AMH levels, sometimes significantly. A study of over 27,000 women found that those on the combined pill, vaginal ring, or implant had AMH levels roughly 22 to 24 percent lower than non-users. Progestin-only pills lowered levels by about 15 percent, and hormonal IUDs by about 7 percent. This suppression is temporary and reverses after stopping the contraceptive, but it means a test taken while you’re on birth control will underestimate your actual ovarian reserve.
If you’re planning to test AMH for fertility planning purposes, being off hormonal contraception for at least a few months gives a more accurate picture. If that’s not practical, your doctor should factor in the expected suppression when reading your results.
What AMH Cannot Tell You
AMH measures quantity, not quality. This is one of the most important distinctions to understand. A study published in Scientific Reports looked at women of advanced reproductive age undergoing IVF and found that AMH had no role in predicting egg quality. Women with low AMH and women with high AMH had similar fertilization rates, similar blastocyst formation rates, and, most importantly, similar live birth rates per embryo transferred. The women with low AMH had fewer eggs to work with, but the eggs they did produce were no less likely to result in a healthy pregnancy.
Egg quality is driven primarily by age. A 30-year-old with a low AMH still tends to have chromosomally healthier eggs than a 40-year-old with a normal AMH. This is why a single AMH number, without context, can be misleading. A low result at a young age is concerning for quantity but not necessarily for your ability to conceive, especially without assistance. A normal result at 42 doesn’t override the age-related decline in egg quality that affects everyone.
AMH also doesn’t predict your ability to conceive naturally in any given month. Ovarian reserve testing was designed for fertility treatment planning, and its value outside that context is real but limited. It’s one data point in a much larger picture that includes your age, partner factors, ovulation patterns, and overall reproductive health.