In the early 1970s, MGA was found to be associated with mammary tumors in beagle dogs, and along with several other progestogens, was withdrawn as an oral contraceptive from several markets including the United Kingdom, Canada, and Germany. It was also under investigation for use as a contraceptive in the United States, but development was discontinued in 1972 following the mammary toxicity findings in dogs, and MGA was never marketed as an oral contraceptive in the United States. Subsequent research, such as monkey studies, revealed that there is no similar risk in humans. Following its withdrawal from the market, MGA was eventually reintroduced for the treatment of hormone-sensitive cancers. In addition, MGA was marketed for veterinary use in dogs in 1969 in the United Kingdom and in 1974 in the United States.