A recent paper from Craig Workman, Alexandra Fietsam, John Kamholz, and Thorsten Rudroff at the University of Iowa suggests women find tDCS more uncomfortable than men. Their paper was titled “Women report more severe sensations from 2 mA and 4 mA transcranial direct current stimulation than men” as was published in the European Journal of Neuroscience.
The authors say “Women report higher sensation severities than men from 2 and 4 mA tDCS and progressively higher severities with increasing intensity, and men reported similar severities in all stimulation conditions… both sexes were able to distinguish sham from 2 mA and 4 mA tDCS and neither was able to discriminate between the 2 mA from 4 mA conditions. This study highlights differences in severity reports between women and men so that future studies should carefully consider for potential differences between women and men to improve sensation tolerability and blinding.”
To get to 4 mA, this study used a Soterix Medical 1×1 device which seems the approach taken by other researchers at the University of Iowa Hospitals and Clinics in prior work, The City College, through a Chattanooga Iontophoresis Device* was used at the 4 mA Medical University of South Carolina trial. According to scientists, there is no evidence 4 mA is hazardous, though as with anything, more research can always be done.
On the topic of gender and tDCS, you may also find this article interesting on “Gender Difference in Gender Bias: Transcranial Direct Current Stimulation Reduces Male’s Gender Stereotypes”
*This device seems no longer available on the market and might be replaced with the ActivaDose tDCS.
Learn more about What is the right amount of current to use in tDCS here