The invention relates to a method for controlling/regulating the boosting of a brake force of a brake system (1), in particular of a power-assisted brake system (1) of a motor vehicle, wherein the brake system (1) comprises a brake force booster (100) having an actuator (130) by means of which a variable additional force (F100) can be imparted to a master brake cylinder (200) of the brake system (1), wherein if a relatively high additional force (F100) is demanded, a partial volume of a brake fluid is discharged from a brake circuit (300) of the brake system (1) in such a way that the actuator (130) of the brake force booster (100) can be placed relatively quickly into a position in which it can impart a greater additional force (F100) to the master brake cylinder (200). The invention also relates to a brake force booster for boosting a brake force of a brake system (1), in particular of a power-assisted brake system (1) of a motor vehicle, having a gearing (120) which can be driven by an electric motor (110), wherein the gearing (120) has an actuator (130) by means of which a piston (210) of a master brake cylinder (200) can be actuated, and wherein the gearing (120) is a cam mechanism (120), in particular an asymmetrical cam mechanism (120), having a control surface (125) or a control groove.