D-Ribose. I love this stuff. I've been taking it for a week now and my energy level has doubled. And I don't ache and my heart isn't scaring me any more. Seriously... this is good stuff. I even found the energy to paint my bedroom - something I've been wanting to do for a year.
Healthy bodies make it on their own, but chronically ill bodies, especially when you have fibromyalgia or chronic fatigue syndrome... which is all related to thyroid disease as many of the symptoms overlap, can use the help. At least that's what I've been reading, and what my experience trying it out has shown, so far.
I'm only posting because I think so many of my beader friends suffer from low energy and may want to look into it too. You can read all about it here: D-Ribose—A Very Powerful and Natural Body Energizer.