When I first started going to the gym I was never really use to the sauna. I noticed that a lot of people would go in before or after their workout and they would come out sweating. So one day I took it upon myself to give it a try and it was my first time and I almost passed out because I stayed in for too long. At first I didn’t see any benefits from it but after a while I thought that it was actually helping me lose extra weight that I did not want. So eventually I started weighing myself before I got in and after I got in and surprisingly there was no major difference. So eventually I went on to do some research to discover if the sauna actually helped people lose weight and here’s the answer:
When you are in the sauna you are losing a tiny bit of weight because you are sweating off water weight. Once you start drinking water again the weight returns. The sauna may also help you burn some extra calories but I would not recommend relying on major sweat sessions alone to shed weight. It is not a real effective tool for significant weight loss.
So at the end of the day if you are someone who has been counting on the sauna to provide significant weight loss for you then I would suggest to look for another avenue. Because at a bear minimum you are only shedding off water weight.
Q's Body Blueprint 