Pallet lever for an escapement mechanism including a balance with a pin of a given pin radius and oscillating over a given radius of gyration, this pallet lever including two horns for cooperation with a pin of this type. These horns are symmetrical to each other relative to a median plane passing through a pallet lever pivot axis, and each includes a concave inner profile over a first radius of curvature greater than or equal to the sum of this radius of gyration and this pin radius, this concave inner profile being adjacent to a convex outer profile over a second radius of curvature less than or equal to the difference between this radius of gyration and this pin radius.