The enhancement of athletic performance using procedures that increase physical ability, such as anabolic steroids, is a familiar phenomenon. Yet recent years have also witnessed the rise of direct interventions into the brain, referred to as “neuro-doping”, that promise to also enhance sports performance. This paper discusses one potential objection to neuro-doping, based on the contribution to athletic achievement, particularly within endurance sports, of effortfully overcoming inner challenges. After introducing the practice of neuro-doping, and the controversies surrounding it, I describe two major mechanisms some have proposed to explain how it might produce its putative performance-enhancing effects. I then clarify the notion of effort, and its relationship to neuro-doping. I also briefly address common concerns about access and safety. My central argument invokes considerations of effort to maintain that we have at least a significant reason for prohibiting the use of neuro-doping in officially regulated endurance competitions – though only conditional upon a specific set of empirical assumptions. I consider three possible objections: that neuro-doping is no different from widely accepted enhancement methods, that it can make athletic competition fairer, and that a broader range of factors can compensate for a reduced scope for effort than I recognize. I ultimately conclude that these objections do not refute the argument from effort, while stressing nonetheless that this argument applies more clearly to hypothetical improved forms of neuro-doping than to existing ones, and is not meant to offer a final overall verdict on how neuro-doping should be regulated.