Here we go. The Thync device isn’t tDCS after all.
From the study:

Abstract
We have developed a neuromodulation approach that targets peripheral nerves and utilizes their afferents as signaling conduits to influence brain function. We investigated the effects of this transdermal electrical neurosignaling (TEN) approach on physiological responses to acute stress induction. TEN was targeted to the ophthalmic and maxillary divisions of the right trigeminal nerve and cervical spinal nerve afferents (C2/C3) using high-frequency, pulse-modulated electrical currents. Compared to active sham stimulation, TEN significantly suppressed sympathetic activity in response to acute stress without impeding cognitive performance. This sympatholytic action of TEN was indicated by significant suppression of heart rate variability changes, galvanic skin responses, and salivary α-amylase levels in response to stress. These observations are consistent with the hypothesis that TEN acted partially by modulating activity in the locus coeruleus and subsequent noradrenergic signaling. Dampening sympathetic tone using TEN in such a manner represents a promising approach to managing daily stress and improving brain health.

And as reported by Daily Dot

While I had only 30 minutes of time with Thync, the team told me that it’s been doing in-depth beta testing for a while. Now, Thync is starting to release some of its findings. In a press release this morning, Thync announced a study showing that its device reduces stress without chemicals. Here’s a quick look at how it worked:

In the study, researchers experimentally induced stress in subjects by exposing them to various environmental stimuli causing fear or cognitive pressure. When Thync scientists examined stress biomarkers in the saliva of subjects at different time points throughout the study, they observed something interesting. They found the levels of salivary α-amylase, an enzyme that increases with stress, as well as noradrenergic and sympathetic activity, significantly dropped for the subjects that received electrical neurosignaling compared to the subjects that received the sham.

The results are exactly what Thync has been saying: That it can de-stress us without putting anything into our bodies. It’s an interesting (though admittedly, very academic) look at how Thync works. But the company also helped me understand its testing and offered an anecdotal look at how the device is being used.

via How the first brain-altering wearable is being tested.