The commercial form of chitosan are marketed as fat blocker pills or tablets. These pills are categorized as a fat eliminator or fat attractor that promotes weight loss. By preventing fat build-up and absorbing fats along the way, people who take fat blockers can eat normally (no dieting or food intake reduction) and still lose their excess weight.

In the United States, the Food and Drug Adminstration regulates the sale of fat blockers in the market, and a big issue remains whether to make them available over-the-counter or restrict them through prescription. Though there are some form of limitation set, there are now over-the-counter fat blocker pills like Xenecal (marketed under the generic name Orlistat).

Though there are now over-the-counter fat blocker pills, the FDA cannot afford to be lenient about this neutriceutical marget segment, recalling that in the 1980s, several fat blocker pills were pulled off after reports of severe side affects on its users, such as bloating, vomiting, nausea and diarrhea including excessive exretion of oil. Though fat blocker pill manufacturers claim that these are signs that the pill is working, consumer watchdogs are wary of the long-term and serious side effects of these pills.

There are claims that an unregulated amount of fat blocker intake blocks or dissolves important natural minerals needed by the body to function normally, such as Vitamins A, D and E and omega-3 and omega 6 fatty acids. Since these are fat-soluble vitamins, fat blocker pills render them useless in the body.