Inhibin‑B is a glycoprotein hormone secreted by Sertoli cells in men and granulosa cells in women.

It plays a role in regulating follicle‑stimulating hormone (FSH) secretion.

Clinical uses include:

Assessing spermatogenesis and male fertility.

Evaluating ovarian reserve in women undergoing fertility treatment.

Monitoring granulosa cell tumors of the ovary.

Supporting diagnosis of disorders of puberty and gonadal function.

Often performed alongside FSH, LH, AMH, and testosterone/estradiol tests for a complete reproductive profile.

Analyte: Serum Inhibin‑B concentration (pg/mL).

Normal Range (varies by sex, age, and lab):

Men: Reflects spermatogenic activity (higher levels = normal sperm production).

Women: Levels vary with menstrual cycle; used to assess ovarian reserve.

Abnormal Findings:

Low Inhibin‑B in men: Suggests impaired spermatogenesis or testicular dysfunction.

Low Inhibin‑B in women: Indicates reduced ovarian reserve, poor response to fertility treatment.

High Inhibin‑B: May indicate granulosa cell tumors or abnormal gonadal activity.

Clinical Use:

Provides a marker of reproductive function.

Helps guide fertility treatment planning.

Supports tumor monitoring and follow‑up.