The FDA recently sent notice to companies selling these and other weight loss products:
http://www.fda.gov/bbs/topics/news/2004/NEW01045.html
Unfortunately, every pill (over-the-counter or prescription) ever devised for weight loss that actually works has come with serious side effects and health risks. At best, you are merely wasting your money on a sham product, such as the fat/carb blockers. At worst, you end up with a stimulant that increases metabolism, but also increases blood pressure, risk of stroke and heart attack, and at depth, there is a potential increase in oxygen toxicity. From DAN's website (
http://www.diversalertnetwork.org/medical/articles/article.asp?articleid=51):
"In 1962, none other than DAN's Chief Executive Officer, Dr. Peter Bennett, while working as a research physiologist at the Royal Navy Physiological Laboratory in England, published a paper (Life Sciences; 12:721-727, 1962) testing the hypothesis that oxygen toxicity and nitrogen narcosis were caused by similar mechanisms.
He found that in rats, sympathomimetics seemed to enhance oxygen toxicity. Pseudoephedrine was not tested specifically, but it is a sympathomimetic, so we might infer that it has a similar effect. In addition, our current understanding of the mechanisms which produce oxygen convulsions would predict that sympathomimetic drugs might enhance susceptibility to oxygen convulsions. It has been shown that drugs which inhibit sympathetic stimulation seem to reduce the likelihood of oxygen convulsions in animals. No human studies have ever been done. Thus, at least a theoretical reason exists why pseudoephedrine should be avoided while diving on high PO2 dives."
Note that ephedra and pseudoephedrine (e.g., Sudafed) are pharmacologically the same thing. Bitter orange and other ingredients have now replaced ephedra in many weight loss supplements, but they all work the same way with the same risks. These are on the FDA short list for future bans, but it is a long, laborious process since legislation ties their hands.
Unfortunately, fitness doesn't come in a bottle, and it's a long, laborious process to acheive. <g> There is much more to fitness than fat loss, and you can only get those benefits from regular exercise and a nutritious diet.
Cameron