A needleless fluid injection device including a flexible shaft with a proximal end, a distal end, an injection lumen extending from the proximal end to the distal end of the shaft, and at least one injection orifice extending through a wall of the injection lumen at the distal end of the shaft. The injection lumen can include a depth- limiting system (462) at its distal end for controlling the depth of insertion of the injection lumen relative to a target tissue of a patient. The injection lumen can alternatively or additionally include at least one guidance feature. The injection lumen can alternatively or additionally include at least one flow-modifying protrusion extending from the inner tubular wall of the injection lumen and toward a longitudinal axis of the injection lumen.
