Abstract Across multiple species, chronic vestibular stimulation activates hypothalamic regions involved in energy homeostasis and reduces body fat. This first-in-human randomised controlled trial evaluated the efficacy and safety of electrical vestibular nerve stimulation (VeNS) as a means of reducing excess body weight and fat. Overweight and obese adults were randomised 1:1 to receive 60 min of daily VeNS (n = 117) or sham stimulation (n = 124) for 6 months, together with a hypocaloric diet. The primary endpoints were weight loss based. Secondary endpoints included reduction in visceral adipose tissue (VAT). It is VAT, more than subcutaneous fat depots, which is particularly associated with the risks associated with obesity. The weight loss based primary endpoints were not met. However, mean change in VAT was significantly greater in the active (− 12.6%) versus the sham (− 4.7%) group (p = 0.03). This suggests that regular VeNS may cause a clinically meaningful reduction in VAT.