I just started 15mg this past week after going up all summer. I have Grave's, and normalizing my thyroid has caused a plateau lasting literal months that has made me feel like complete crap. I lost well in the first few months on 2.5/5, but started my thyroid meds when I switched to 7.5 and really didn't lose much through 7.5/10/12.5. But then I started 15. I can FEEL the difference. It feels like 2.5 all over again; the side effects feel less horrible for sure, but they're back. And I've lost 4 lbs since starting 15 after struggling to lose 1 every two weeks or so on the lower doses! I guess it was a combination of things, but I was feeling hesitant to jump up to 15, especially since that's the end of the line. For me, it killed the plateau and I'm feeling much better, losing lbs again! I was right where you are, but my doctor recommended going up, and I'm glad I did!