Martindale was previously president of the drugstore chain and chief executive of Rite Aid Stores.
Moran will become GNC’s non-executive chairman replacing Michael Hines who will step down with effect from September 11 but remain on the board.
Commenting on Martindale’s appointment, Hines said. "Ken is a proven leader with deep retail expertise, intimate knowledge of our business through his years of leadership with our partner, Rite Aid, and a record of success in transforming retail business models,"
Meanwhile, confirming Martindale’s departure, Rite Aid said it had promoted Bryan Everett - currently executive vice president of store operations - to the newly created position of chief operating officer.
In pre-market trade, Rite Aid shares were up 1.2% at US$2.42, while GMC shares were 1.8% lower at US$8.05.