Antimullerian hormone is a protein hormone produced by human and other mammalian gonads. In males, produced by fetal testes prevents the development of the mullerian ducts into the uterus and other mullerian structures. Older terms for AMH include mullerian inhibiting substance (MIS) and mullerian inhibiting hormone (MIH).

The gene for AMH is AMH, on chromosome 19p13.3.AMH is a dimeric glycoprotein member of the transforming growth factor-β (TGF-β) family of protein hormones. Amounts of AMH in produced and measurable in the blood vary by age and sex. AMH works by interacting with specific receptors on the surfaces of the cells of target tissues. The best known and most specific effect, mediated through the AMH type II receptors, includes programmed cell death (apoptosis) of the target tissue (the fetal mullerian ducts).

AMH from fetal testes play an important role in sexual differentiation of the internal reproductive organs. The best understood function and most important sex difference in AMH production occurs in fetal life, when the testes of male fetuses produce AMH to block development and cause regression of the mullerian ducts. This prevents the mullerian ducts from developing into fallopian tubes, uterus, cervix, and upper vagina. Fetal ovaries do not make AMH, which allows these structures to develop in females.

AMH is produced by ovarian granulosa cells after puberty in females but the function is unknown, and absence does not seem to affect ovarian function or fertility.

AMH production by the Sertoli cells of the testes remains high throughout childhood but declines to low levels during puberty and adult life. AMH measurements have become widely used in the last few years in the evaluation of testicular presence and function in infants with intersex conditions, ambiguous genitalia, and cryptorchidism.

AMH production by ovaries is minimal in fetal life but can become measurable after puberty. Functions in females are not well understood.

Persistent mullerian duct syndrome (PMDS) refers to the condition in which a male possesses mullerian structures such as a uterus. Testes are usually undescended. The AMH gene (AMH) or the gene (AMH-RII) for its receptor are usually abnormal.

See also sexual differentiation