At some point, you will be completely dependent on hormone replacement
. For me, that's the point I looked forward to because I knew the only hormones I'm getting are the med I take every day, so my levels stay pretty steady.
Hashimoto's does not cause weight gain; Hashimoto's causes hypothyroidism, which causes weight gain. Your thyroid controls many of your body processes, including, but not limited to: metabolism, heart rate, body temp.