Markers · Hormones
An AMH of 0.8, flagged low. AMH, read against your age.
What AMH measures, what it does in the body, why it's tested and the two ranges it's read against, all from Merlin's own biomarker catalogue, then the markers that check it.
What AMH is
In women, AMH is the best single blood marker of ovarian reserve - roughly how many eggs remain. It's made by the small developing follicles, so it falls steadily with age and is high in PCOS. It's a snapshot of reproductive runway, not of monthly fertility or hormone balance.
What it does in the body
AMH is secreted by granulosa cells of pre-antral and small antral follicles, and its level reflects the size of the remaining follicle pool. It is relatively cycle-independent, which is why it can be drawn on any day.
Why it's tested
Used to estimate ovarian reserve, guide fertility planning and IVF stimulation protocols, support a PCOS picture (elevated), and assess reproductive aging. It does not predict natural conception in a given cycle.
The two ranges
The reference range reflects population statistics. The target reflects physiology.
- Lab reference range
- Strongly age-dependent; low < 1.0 ng/mL suggests diminished ovarian reserve, high > 4.5 ng/mL is common in PCOS (assay-dependent)
- Functional target
- Women (reproductive age): ~1.0-4.0 ng/mL, declining with age. Interpret against age.
Those are different numbers, and you deserve to know which one you're looking at. Merlin reads your result against both.
The markers that check it
The small growing follicles make AMH continuously, largely independent of cycle day, so it can be drawn on any day. It tracks the size of the remaining follicle pool. It's a quantity signal, not an egg-quality verdict, and it doesn't predict natural conception either way.
A high AMH, above about 4.5 ng/mL, usually reflects a large pool of small follicles, common in PCOS, rather than extra fertility. It's read with LH against FSH, androgens and how regular your cycles are.
A lower AMH, under about 1.0 ng/mL, reflects a smaller remaining pool. If you're under 40, ask a provider for an ovarian-reserve conversation: an antral follicle count, with FSH and estradiol. A normal FSH doesn't settle it when the same draw's estradiol is high, because a high estradiol holds FSH down. In the 40s, a lower reserve is itself expected for age.
Elevated TPO antibodies make an AMH check reasonable, because they're associated with premature ovarian insufficiency.
If you're planning a pregnancy: AMH is one read in a pre-conception panel, beside FSH, estradiol and your cycle history, and it's most useful for planning if assisted reproduction is ever on the table. Smoking means a lower AMH at any given age, and a large recent study found vaping lowered it too.
Where this lives
A Field Guide to Female Fertility
The field guide that covers AMH in depth, whole and public.
In a real read
The real read on this site is a Cardiovascular one, so there's no hormone panel in it. What it shows is the shape: one system, thought all the way through, with the score, the narrative and the layers underneath. A hormone panel gets one of these too, with AMH read against your age and beside the FSH and estradiol from your early-cycle draw.
A real Cardiovascular surface from a real anonymized panel: the score, the narrative, the layers underneath. Yours will be built the same way, on your own numbers.
Educational context for your conversations with your licensed healthcare provider, not a diagnosis or a treatment plan. Merlin reads results; it doesn't diagnose.
No AMH result yet? You can order it inside Merlin: it's on Ovarian Reserve - Cycle Day 2-5 ($140) and Preconception (Female) ($257), which takes two draws.
Bring the panel this number came from. Merlin reads it against everything else you have, every system and every year, then shows you what it means and what's worth finding out next. Start with your first month.