What setting were you using?
I'm going to try limiting sessions to two per day (20 min each) on setting 3. One in the morning one at night, just before bed.
My wife only had one session yesterday (20min on setting 3), she felt very relaxed after that. Tonight I'll find out how she felt today.
That reminds me I had a night-sweat last night. I'm not sure if that was a reaction to the Bio Tuner?