We are concerned that the rapid development and increased accessibility of non-invasive technologies with alleged brain-enhancing capabilities is allowing commercial interest to outpace regulatory mechanisms (see Nature 531, 283–284; 2016 and Nature 531, S6–S8; 2016).

Only limited technical ability is required to build a brain-stimulation device at home — or to dress it up and market it commercially. Even though electrical current can endanger cardiovascular and neural function (see go.nature.com/ej3kgx), there are currently no requirements for safety or efficacy testing of home-use devices through clinical-style trials. Beyond the safety of the devices themselves, the impact of regular or sustained personal use of brain stimulators is unknown.

The public may not appreciate that companies are subject to a strict regulatory framework if their product claims to help an individual to achieve normal function (that is, a treatment), but not if it is sold to enhance function. We urge governments to align their regulatory standards for both applications.