ContraPest is a contraceptive pest control product for small mammals such as mice and rats, developed by the U.S. biotechnology company SenesTech. It is a flavored liquid, designed to be attractive to, and to be consumed by, the target animals.
The product's original name "Mouseopause" is a play on the words "mouse menopause". The product was approved for commercial use by the U.S. Environmental Protection Agency in August 2016.
ContraPest contains the ovotoxic chemical 4-vinylcyclohexene diepoxide (VCD), which is a known killer of oocytes in immature ovarian follicles. The rat version of ContraPest also contains triptolide, which the company reports has adverse reproductive effects on both males and females. The product has been successfully used to sterilize both male and female mice, rats, and dogs.