I think you're on a bit of a wild goose chase: artificial hormones cause weight gain. It's almost universal, and its virtually impossible to fight.

...but at 5'7" and 130-some pounds, that's still at the low end of a healthy weight range. I wouldn't sweat it. You work out, so you're obviously fit enough. I know I wouldn't be able to get down to 125 lbs without notable LBM loss.