This product is too new for me to give you much info on. It is a thyroid "stimulator," not actual t-3 hormone. It may be similar to Biotest's Hot Rox, but I'm not sure. In the past, certain supps like kelp and gugglesterones have been used to increase thyroid output, but I'm not sure what the "active" ingredient in SAN's product is. I'll let you know when I have more, but I wouldn't rush to buy it yet.