Methods and devices are provided for regulating a hydraulic restriction system. In general, the methods and devices can allow for non-invasive pressure control using a flow control mechanism. The flow control mechanism can be disposed between an implantable restriction device and a fluid source and include an adjustable, variably-sized fluid communication member in fluid communication with the restriction device and the fluid source. The geometry of the fluid communication member can control a rate of fluid flow between the restriction device and the fluid source, thereby also regulating a rate at which a pressure of fluid within the restriction device changes. Alternatively, the fluid flow control mechanism can include a biasing mechanism that can control the rate of fluid flow between the restriction device and the fluid source.