Agree with the others. Some were kind of tingly others were some zaps that at the time were pretty uncomfortable but only lasted a millisecond so it was OK. I never lost any sleep in the anticipation of it or afterwards. But I'm a tough cookie and harldy anything bothers me. Except if my grandbabies are sick! Oldest one had a toothache today and had to have it removed., She loved the laughing gas!