Just make sure you take about 2 hours before start of booking and drink a good glass of water to help on many levels, I'm ok through out and pop at the end, my reg is going to make me pop straight away next time so we can see if I can get another pop as never tried and want to see if it works, have no problem with a pop after get home, middle of night and morning ( am I taking too higha dose ? ) but never wanted to risk paying for an hour, having a quick pop then not able to do again, but now my reg knows me better we're going to see what happens ?