An injection needle, for injection into a body tissue, is flexible in the introduced or post-inserted state and comprises a channel for the introduction of a fluid. The injection needle is at least partly made from at least one material which is rigid in one state and flexible in a second state. Alternatively or concurrently, the injection needle is rigid on application of a force to the needle along the longitudinal direction of a needle longitudinal axis and is flexible on application of a force in the radial direction relative to the needle longitudinal axis.