Vorlix

From The Stargate Omnipedia

Term the Vyans use to describe the starting point of a period of mass amnesia that befell the entire population. This period was set about when the Destroyer of Worlds, Linea, used a substance called Dargol in an attempt to eventually make herself younger.

KEY EPISODE

Past and Present - SG-1 arrives at a world where the people have suffered from the Vorlix.