Desegranine is a drug used by the Cardassian Obsidian Order to help their undercover operatives regain the memories of their original lives.
As part of Iliana Ghemor's mission to infiltrate the Bajoran Resistance, it was planned she would be injected with desegranine to restore her memories. (DS9 novel: Fearful Symmetry)
In 2371, Corbin Entek had Kira Nerys administered with desegranine, although he knew that as she was not actually Iliana Ghemor it would have no effect on her. (DS9 episode: "Second Skin")