After battling with my weight and extreme fatigue for as long as I can remember I really thought that there was nothing I could do about it. I was diagnosed with hypothyroidism and prescribed Synthroid, which helped with other symptoms, but I still could not lose weight and was extremely tired. My endo suggested I may have the MTHFR gene mutation and suggested I cut out all enriched grain products and take a bioavailable b-complex vitamin. It worked! I started taking this vitamin and stopped eating enriched grains and within days I had more energy than I have had in a long time. I also started noticing that I was not very hungry, which lead me to discover that b-complex vitamins can also be an appetite supressant, so that was a nice surprise. I have not tried other b-complex vitamins, so I can't say how these compare to other brands, but I can tell you these work