Provera is a hormone (progesterone). My hormones were unbalanced and I was prescribed this to get them back in order. I have never taken any hormones and it was quite shocking to step on the scale and see 10 lbs in 8 days. I now officially weigh more than I did when I started the diet and I weigh more than I ever have in my life. It's quite depressing, I hope though that its water weight.