Cook joined on January transfer deadline day and made nine appearances for the Addicks, and now returns to relegation threatened Fulham.
Lita managed to score three times in a red shirt, including a brace which beat Plymouth 2-1 when the Addicks were down to ten men.
Addicks boss Alan Pardew has praised both of their efforts and with Cook leaving, it gives youngsters Jonjo Shelvey and Scott Wagstaff a chance to make their debut.