A study done by Oregon State University has confirmed that weight loss supplements do not work and can cause anxiety , insomnia, liver problems and stroke . I have tried a few of these supplements and did not respond well , I believe that proper diet and vitamin / mineral supplementation work best . The body is a delicate eco system and when that balance is shaken with overstimulation from these products you don't know if you are coming or going. The supplements have warnings listed in very small print that make the user "aware" of the hazards, feeding into the need for a quick weight loss fix. As a fitness professional , I can not stress to my clients enough that these quick fix supplements can not replace hardwork , lifestyle adjustment and self worth.