A refillable bottle for dispensing a fluid product, comprising a container formed in a body. The bottle comprises a dispensing device and a valve for filling the container arranged to allow a product source to be brought into communication with the container to fill the container. The valve comprises a conduit for communication between the source and the container, and having a seat equipped with a flap valve movable relative to the seat between a sealed closed position and an open position of the conduit when the bottle is in an upside-down position. The valve has an upper cylindrical coupling in which the flap valve is movably mounted by forming, inside the cylindrical coupling, a downstream portion of the conduit which discharges into the container by means of a passage. The upper cylindrical coupling is cylindrical in revolution and has a notch arranged so that the passage is asymmetrical.