The US Food and Drug Administration has issued guidance on implanted brain-computer interfaces (BCI), outlining a series of recommendations for non-clinical testing and study design consideration for clinical studies which involve such devices. The guidance outlines the need for BCIs to encompass electrical and electromagnetic safety needs and ensure long-term compatibility with users' blood, cerebrospinal, and nerve tissue. Technology developers are advised to use non-clinical testing to mitigate potential risks before designing clinical studies that involve BCIs. Another recommendation is to consider 'human factors' throughout the entire design of BCIs, to allow the elimination of harmful situations that may arise based on the characteristics of a device's intended users and the environments in which they would use the device. Moreover, it is suggested that, where caregivers are required to assist patients using BCIs, the clinical trial should assess both device and caregiver performance.