The Bluetooth low-energy (BLE) mesh profile, currently standardized by the Bluetooth Special Interest Group (SIG), assumes that friend and relay nodes should be continuously scanning the channel ready to receive any incoming transmissions (TXs). This is very inefficient in terms of energy consumption. Hence, we present BMADS, an asynchronous dynamic scanning mechanism designed to reduce the overall energy consumption of the mesh network. BMADS is implemented as a new feature for the currently published BLE mesh specifications without modifying its core. This feature reduces the scanning cycles of the nodes, but still ensuring the reliability. To make this possible, BMADS sends a new control message sequence before transmitting the data. This sequence puts the nodes into continuous scan mode, preparing the network for data TX. The proposal can be used in BLE sensor networks that can tolerate a certain TX delay and require especially low-energy consumption. BMADS allows a theoretical reduction in the energy consumption of the relay nodes up to 98%.