Lab marker · Low

Low Inhibin B: what it means

A Inhibin B result below the normal range is considered low. Here is what a reduced Inhibin B can point to, and when it is worth discussing with a doctor.

Reference range: highly cycle- and sex-dependent (no single normal range); in women reflects ovarian reserve, in men reflects sperm-producing (Sertoli-cell) function — always interpreted with FSH and AMH

Understand your full result

What a low Inhibin B can mean

  • Diminished ovarian reserve — fewer remaining eggs; inhibin B falls as FSH rises.
  • Approaching or established menopause — the ovarian pool is depleting.
  • Testicular failure in men — low inhibin B with a high FSH suggests impaired sperm production.
  • Suppression of the pituitary–gonadal axis — from certain hormonal states or treatments.

When to discuss with a doctor

Inhibin B is a specialist fertility and reproductive test rather than a routine one. In women, it is used as part of assessing ovarian reserve during a fertility work-up, always alongside FSH and usually AMH, which together give a fuller picture than any single value. In men, a low inhibin B with a raised FSH supports impaired sperm production. It is also followed as a tumour marker in granulosa cell tumours of the ovary. Because inhibin B swings widely with cycle phase, age and sex, one value in isolation means little. Mediora.AI shows inhibin B alongside FSH, AMH and estradiol so the ovarian-reserve or testicular pattern reads together; the interpretation belongs with your gynaecologist or fertility specialist.

Keep reading

One value is a snapshot. Upload the full test to see every marker explained together.

Upload your test - free

Mediora.AI is informational - interpretation, not a diagnosis. A single out-of-range value is common and often benign; always discuss decisions with your doctor.