What is Logynon?
Norgestrel is an old progestin that has been used in hormonal contraceptives. Norgestrel is a mixture of two stereoisomers, dextro-norgestrel (CAS# ) and levo-norgestrel (CAS# ). Only levonorgestrel is biologically active. Therefore, while some medications may contain dextronorgestrel, they are often labeled in terms of their levonorgestrel content only, ignoring the inert isomer.
Norgestrel has also been used as an emergency contraceptive in the Yuzpe regimen.