Dimdazenil (trade name Junoenil) is a pharmaceutical drug for insomnia.^[1] It is a benzodiazepine derivative and a partial positive allosteric modulator of the GABA_A receptor^[2] with two- to four-fold higher functional affinity for the α₁ subunit relative to the α₂, α₃, and α₅ subunits.

Dimdezenil shows effectiveness in the treatment of insomnia, but has less intrinsic activity in comparison to currently-marketed benzodiazepines and the Z-drugs;^[3] however, it is thought that the lower efficacy may result in fewer side effects, such as motor incoordination.^[3] In China, dimdezenil is approved for short-term treatment of insomnia.^[4]

Dimdezenil was originally developed by Roche, based on preclinical data, as a non-sedating anxiolytic, but was found to produce sedation in humans in phase I clinical trials. For this reason, it was subsequently licensed to Evotec, which is now developing it for the treatment of insomnia.^[3] By 2007, dimdezenil completed phase II clinical trials for this indication, with positive findings reported.^[5] In China, the drug was developed by Zhejiang Jingxin Pharmaceutical.