I'm honestly not familiar with most off the "thyroid-effecting" ingredients in this product. But, be careful manipulating your thyroid hormone levels by any means!
I noticed (and am a little surprised) that this product contains 1,3-Dimethylamylamine. I know there is/was a push to ban it from many products. Most sites either list former straight 1,3-Dimethylamylamine products as "discontinued" or not at all. It looks like USP still includes it in their Jack3d and, of course, this formula. That may have something to do with the synthetic vs geranium extract forms. I haven't kept up on the details of the ban.
Many people raved about Jack3d. The combination of 1,3-Dimethylamylamine and caffeine provide a truly synergistic effect with each enhancing the effects of the other. DMMA also reportedly reduces "caffeine crash" to a great degree.
I'm glad it's working for you!
I don't give out advice here. I will say that, personally, I wouldn't stay on the stuff for too long.