Thync is a startup funded by Khosla Ventures, selling an electronic wearable device it claims will improve mood.[2] Its makers claim the device works by neurostimulation techniques such as TENS and tDCS.

Some trial users feel no effect while others claim benefits.[3]

One evaluator compared it drinking an espresso accompanied by a tingle of prickly heat behind the ear.[4]

The Food and Drug Administration has declined to classify it as a medical device under their purview.[4]