 Like other progestins but unlike progesterone, which forms sedative neurosteroid metabolites, dydrogesterone is not able to be metabolized in a similar way, and for this reason, is non-sedative.The medication and 20α-DHD do not inhibit 5α-reductase.Dydrogesterone has been found to inhibit myometrium contractility via an undefined progesterone receptor-independent mechanism "in vivo" in pregnant rats and "in vitro" in human tissue at concentrations at which progesterone and other progestogens do not.