A regulatable brake booster and to a method and a control unit for operating same. Using the method for operating the brake booster, as well as the embodiment of the brake booster, a reaction on a driver may be avoided or reduced by an offset of the brake pedal or by a changed operating force in response to a change in the supporting force. The change in the supporting force is particularly an adjustment of the braking effect of an hydraulic braking system to the braking effect of a regenerative braking system.