This note presents saturated controllers to stabilize uncertain feedforward nonlinear systems whose nominal dynamics contains uncertain "gains" and is subject to linear perturbations. We assign a class of saturated controllers within which multiplicative coefficients appear before both states and saturation functions, and the convergence analysis is conducted in the following way: to verify the reduction of saturated terms, we calculate the time derivative of a boundary surface in a small domain when the states reach the boundary surface; to prove the asymptotic stability of the corresponding reduced system, we use an M-matrix-based comparison principle. In this way, the suggested algorithm does not depend on the small-gain theory, and is suitable for dealing with strongly nonlinear underactuated systems including the cart-pendulum system, the overhead crane system. and the uncertain vertical takeoff and landing vehicle.