DIMP (developmental code name Ro 7-8117), or N-(3,5-dimethyl-4-isoxazolylmethyl)phthalimide, is a nonsteroidal antiandrogen (NSAA) structurally related to thalidomide (which also binds to and antagonizes the androgen receptor (AR))[1][2][3] that was first described in 1973 and was never marketed.

[1][2][3] The drug is a selective, competitive, silent antagonist of the AR,[4][6] although it is described as an "only relatively weak competitor".

[7][8] Its relative binding affinity for the androgen receptor is about 2.6% of that of metribolone.

[9] DIMP possesses no androgenic, estrogenic, progestogenic, or antigonadotropic activity,[4] but it does reverse the antigonadotropic effects of testosterone, indicating that, like other pure AR antagonists, it is progonadotropic.

[4] DIMP is the lead antiandrogen of the phthalimide group of nonsteroidal AR ligands, and a variety of AR ligands with higher affinity for the AR have been derived from DIMP and thalidomide.