I have been taking Kelp Formula for quite a while now, in conjunction with Thyroid Support Formula, and the benefits to my energy levels have been marked. I still have "good days and bad days", but previously I was having nothing but bad days, so I believe this is a *huge* improvement.
During the summer, I was bounding with energy, so I suspect at least part of the "bad days" is down to the lower levels of sunlight we've had through the winter, as I am experiencing more "good days" again at the moment.