Chitosan is extracted from the shells of crustaceans, such as shrimp and crab. This substance is not digestible but may have beneficial effects on the gastrointestinal tract. Chitosan appears to reduce the absorption of bile acids or cholesterol; either of these effects may cause a lowering of blood cholesterol, however studies regarding its ability to lower cholesterol have been mixed. A study published in Finland did not show it to have much of an effect on cholesterol levels, whereas another study conducted in Argentina showed diabetics who ate bread containing chitosan had lower cholesterol levels. It's frustrating when researchers come to opposite conclusions.

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Suggested Use: Two chitosan capsules before lunch and two capsules before dinner. Drink at least 4 glasses of fluid daily.

Chitosan, a fiber derived from chitin in shell-fish, is a nondigestible aminopolysaccharide synthesized by removing acetyl groups from chitin, through a process called deacetylation. This process enhances its activity by improving its solubility in the acidic environment of the stomach.
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Chitosan (minimum 90% deacetylated chitin) 500 mg per pill

Review of research study
There is mixed evidence whether chitosan is more effective than placebo in the short-term treatment of overweight and obesity. Many trials to date have been of poor quality and results have been variable. Results obtained from high quality trials indicate that the effect of chitosan on body weight is minimal, if any. A nutrient that can limit appetite is 5-HTP which converts into serotonin. Acetylcarnitine may also be helpful in some users.
   Studies evaluating the role of chitosan in weight loss and cholesterol reduction have produced inconsistent results. I'm not ready to endorse the use of chitosan by itself for weight loss or cholesterol reduction at this time. Perhaps chitosan may be a useful addition to cholesterol reduction when used along with other supplements. Time will tell. If you wish to reduce body weight or maintain healthy cholesterol levels, see other options provided on these web pages: weight loss information and cholesterol.

Adv Food Nutr Res. 2014. Antioxidant effects of chitin, chitosan, and their derivatives. Chitin, chitosan, and their derivatives are considered to promote diverse activities, including antioxidant, antihypertensive, anti-inflammatory, anticoagulant, antitumor and anticancer, antimicrobial, hypocholesterolemic, and antidiabetic effects, one of the most crucial of which is the antioxidant effect. By modulating and improving physiological functions, chitin, chitosan, and their derivatives may provide novel therapeutic applications for the prevention or treatment of chronic diseases. Antioxidant activity of chitin, chitosan, and their derivatives can be attributed to in vitro and in vivo free radical-scavenging activities. Antioxidant effect of chitin, chitosan, and their derivatives may be used as functional ingredients in food formulations to promote consumer health and to improve the shelf life of food products.

Allergy
Can you tell me if it is safe to take chitosan if a person is allergic to shell fish, such as shrimp?
    Chitin is a polysaccharide derived from sources like crab, lobster and shrimp shells, and marine coral, that are not eaten as foods. Chitin is used to make various other substances, including chitosan, which is derived from chitin by heating it with a chemical solution. See below for an article on this topic.

Chitins and chitosans as immunoadjuvants and non-allergenic drug carriers.
Mar Drugs. 2010. University of Ancona, Ancona, Italy.
Due to the fact that some individuals are allergic to crustaceans, the presumed relationship between allergy and the presence of chitin in crustaceans has been investigated. There is quite a large body of knowledge today on the use of chitosans as biomaterials, and more specifically as drug carriers for a variety of applications: the delivery routes being the same as those adopted for the immunological studies. Said articles, that devote attention to the safety and biocompatibility aspects, never reported intolerance or allergy in individuals and animals, even when the quantities of chitosan used in single experiments were quite large. Therefore, it is concluded that crab, shrimp, prawn and lobster chitins, as well as chitosans of all grades, once purified, should not be considered as "crustacean derivatives", because the isolation procedures have removed proteins, fats and other contaminants to such an extent as to allow them to be classified as chemicals regardless of their origin.

Cholesterol reduction
Improvement of HDL- and LDL-cholesterol levels in diabetic subjects by feeding bread containing chitosan.
J Med Food. 2003.
In this work we evaluated the efficacy and safety of a bread formulation containing chitosan in dyslipidemic type 2 diabetic subjects. For this purpose a total of 18 patients were allowed to incorporate to their habitual diets 120 g/day of bread containing 2% (wt/wt) chitosan or standard bread. Before the study and after 12 weeks on the modified diet, the following parameters were evaluated: body weight, plasma cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride, and hemoglobin A(1c) (HbA(1c)). Compared with the control group, the patients receiving chitosan-containing bread decreased their mean levels of LDL-cholesterol and significantly increased their mean levels of HDL-cholesterol at the end of the study. There were no significant differences in the body weight, serum triglyceride, and HbA(1c).

The effect of long-term microcrystalline chitosan therapy on plasma lipids and glucose concentrations in subjects with increased plasma total cholesterol: a randomised placebo-controlled double-blind crossover trial in healthy men and women.
Tampere University Hospital, Tampere, Finland.
A total of 130 middle-aged men and women without severe disease and with a total cholesterol of 4.8-6.8 mmol/l and triglycerides below 3.0 mmol/l were randomised into two treatment groups. At the beginning of the 10-month trial, all participants received placebo twice daily during a 1-month run-in period. Subsequently, group 1 first received placebo twice daily for 3 months and then 1.2 g chitosan twice daily for 3 months. Correspondingly, group 2 received 1.2 g chitosan twice daily during the first and placebo twice daily during the second 3-month period. Treatment with chitosan had no effect on the concentrations of plasma lipids or glucose in healthy middle-aged men and women with moderately increased plasma cholesterol concentrations.

Fat excretion
Efficacy of a novel chitosan formulation on fecal fat excretion: a double-blind, crossover, placebo-controlled study.
J Med. 2002.
The ability of a novel chitosan formulation to influence gastrointestinal fat absorption in vivo was examined in a double-blind, placebo-controlled, crossover study by determining the content of total fat in feces in two groups of subjects. During the placebo and the test periods, the subjects were administered six capsules three times daily 10 minutes before meals for three days and for the two days of the stool collection. A daily serving of six tablets of the test compound contained 2100 mg chitosan and 300 mg psyllium husk seeds. The average daily increase in fecal fat of 3-4 grams over control could account for a decrease in calorie consumption of 30-40 kcal per day. A total of 19 subjects completed both parts of the study.

Weight Loss
Evaluating efficacy of a chitosan product using a double-blinded, placebo-controlled protocol.
J Am Coll Nutr. 2006. Health and Medical Research Center, 4940 Broadway, Suite 201, San Antonio, TX
To examine the safety and efficacy of a chitosan dietary supplement on body composition under free-living conditions. In a randomized, double-blinded, placebo-controlled dietary intervention protocol, subjects were assigned to a chitosan treatment group, a placebo group (PLA) and a control group (CTL). A total of 150 overweight adults enrolled; 134 (89%) completed the study; 111 (82%) were women who were similarly distributed in the three groups. The chitosan treatment group took six 500 mg chitosan capsules per day and both chitosan treatment and PLA groups wore pedometers during their waking hours and recorded daily step totals. The CTL group followed weight loss programs of their choice, and took the same baseline and ending tests. Outcome measures were Dual Energy X-ray Absorptiometry tests, fasting blood chemistries, and self-reported daily activity levels and caloric intakes. Compared to the control group, the chitosan treatment group lost more weight and fat mass. Compared to PLA, the chitosan treatment group lost more weight, % fat, fat mass. These data provide evidence for the efficacy of a chitosan compound to facilitate the depletion of excess body fat under free-living conditions with minimal loss of fat-free or lean body mass.

The effect of the dietary supplement, Chitosan, on body weight: a randomised controlled trial in 250 overweight and obese adults.
Int J Obes Relat Metab Disord. 2004.
Chitosan, a deacetylated chitin, is a widely available dietary supplement purported to decrease body weight and serum lipids through gastrointestinal fat binding. Although evaluated in a number of trials, its efficacy remains in dispute. To evaluate the efficacy of chitosan for weight loss in overweight and obese adults, a 24-week randomised, double-blind, placebo-controlled trial was conducted at the University of Auckland. A total of 250 participants were randomly assigned to receive 3 g chitosan/day (n=125) or placebo (n=125). All participants received standardised dietary and lifestyle advice for weight loss. Adherence was monitored by capsule counts. In an intention-to-treat analysis with the last observation carried forward, the chitosan group lost more body weight than the placebo group during the 24-week intervention, but effects were small. Similar small changes occurred in circulating total and LDL cholesterol, and glucose. There were no significant differences between groups for any of the other measured outcomes. In this 24-week trial, chitosan treatment did not result in a clinically significant loss of body weight compared with placebo.

Effect of chitosan in complex management of obesity
Zahorska-Markiewicz B. Katedra Patofizjologii Sl. AM w Katowicach.
The aim of the present study was to verify the effect of chitosan as a possible adjuvant in the complex management of obesity. Fifty obese women (22-59 years, BMI > 30) participated in the study. A six months program consisted of 2-hour meetings with a physician, psychologist and dietitian, in a group of about 20 persons, every two weeks. Low calorie diet (1000 kcal/day), physical activity and behaviour modification were recommended. Supplementation with chitosan was evaluated in a randomized, placebo-controlled, double-blind study. In the chitosan group, participants received ChitininN (Primex Ingredients ASA, Avaldsnes, Norway) i.e. 750 mg pure chitosan per tablet, two tablets three times daily before each main meal. Significantly higher body weight loss was noted in the chitosan-supplemented group (15.9 kg) than in the placebo group (10.9 kg) Also a greater decrease of systolic and diastolic blood pressure was observed in the chitosan group. There was no difference between the groups in the decrease of LDL and total cholesterol.

Randomized, double-blind trial of chitosan for body weight reduction.
Pittler MH. University of Exeter, United Kingdom. Eur J Clin Nutr 1999
Overweight and obesity is a prevalent and costly threat to public health. Compelling evidence links overweight and obesity with serious disorders such as cardiovascular diseases and diabetes. Dietary regimen are notoriously burdened with poor compliance. Chitosan is promoted in the US and other countries as an oral remedy to reduce fat absorption and has now been incorporated as a major constituent into several over-the-counter remedies. The primary aim of this study is to investigate the clinical effectiveness of oral chitosan for body weight reduction. Thirty-four overweight volunteers were included in a randomized placebo-controlled double-blind trial. Subjects were assigned to receive either four capsules of chitosan or indistinguishable placebo twice daily for 28 consecutive days. Measurements were taken at baseline, after 14 and 28d of treatment. Subjects maintained their normal diet and documented the type and amount of food consumed. Adverse effects were assessed and compliance monitored. Data from 30 subjects were entered into an intention-to-treat analysis. After four weeks of treatment, body mass index, serum cholesterol, triglycerides, vitamin A, D, E and beta-carotene were not significantly different in subjects receiving chitosan compared to those receiving placebo. Vitamin K was significantly increased after four weeks in the chitosan group compared with placebo. Compliance was 91% and 96% for chitosan and placebo groups respectively. The above data suggest that chitosan in the administered dosage, without dietary alterations, does not reduce body weight in overweight subjects. No serious adverse effects were reported.

Chitosan side effects, safety, toxicity
I am not aware of any significant side effects with chitosan supplement intake.

Safety aspects and cholesterol-lowering efficacy of chitosan tablets.
J Am Coll Nutr. 2008; Tapola NS, Lyyra ML, Kolehmainen RM, Sarkkinen ES, Schauss AG. Oy Foodfiles Ltd, Neulaniementie, Finland.
The purpose of this study was to determine the effect of two different doses of chitosan on serum fat-soluble vitamin concentrations, cholesterol concentrations, and other safety parameters. A total of 65 men and women consumed 0, 4.5, 6.75 g per day of chitosan or 6.75 g per day glucomannan for eight weeks in a parallel, placebo-controlled, single-blind study. Altogether, 56 participants completed the study. No differences were detected among the treatments in serum vitamins (vitamin A, vitamin E, 25-hydroxyvitamin D), carotenes (alpha- and beta-carotene), clinical chemistry or hematology measurements. The changes in the total and LDL-cholesterol concentrations among the study groups were not statistically significant. In the present study, the consumption of chitosan tablets was found to be safe, but there was no significant effect on cholesterol concentration.

Delivery and absorption
The absorption enhancing effects of chitosan and its derivatives have been intensively studied in recent years. It has been shown that these compounds are potent absorption enhancers. Chitosan is only soluble in acidic environments and is therefore incapable of enhancing absorption in the small intestine, the main absorption area in the gastrointestinal tract.
     Chitosan has great potential for pharmaceutical applications due to its biocompatibility, high charge density, non-toxicity and mucoadhesion. It has been shown that it improves the dissolution of poorly soluble drugs. Gel formation can be obtained by interactions of chitosans with low molecular counterions such as polyphosphates, sulphates and crosslinking with glutaraldehyde. This gelling property allows a wide range of applications such as coating of pharmaceuticals and food products, gel entrapment of biochemicals, plant embryo, whole cells, microorganism and algae.
     Besides its low toxicity and good ocular tolerance, chitosan exhibits favourable biological behaviour, such as bioadhesion- and permeability-enhancing properties, and also interesting physico-chemical characteristics, which make it a unique material for the design of ocular drug delivery vehicles.

The Varied uses
Chitosan is a partially deacetylated polymer obtained from the alkaline deacetylation of chitin. Chitosan exhibits a variety of physicochemical and biological properties resulting in numerous applications in fields such as waste and water treatment, agriculture, fabric and textiles, cosmetics, nutritional enhancement, and food processing. In addition to its lack of toxicity and allergenicity, and its biocompatibility, biodegradability and bioactivity make it a very attractive substance for diverse applications as a biomaterial in pharmaceutical and medical fields, where it has been used for systemic and local delivery of drugs and vaccines. Research indicates that chitosan can increase crop yields, and clean and clear up pools. Chitosan has been known to aid plants' immune systems while they are growing. When placed on a seed, it induces protective measured within the growing plant.

Questions
Is a chitosan pill necessary if a person is taking a weight loss reducing supplement?
    There are many such products over the counter, it is difficult to make generalizations, but I don't see much harm in taking this supplement in reasonable dosages.

Source Naturals - Diet Chitosan 500 mg, 240 Capsules
Chitosan, a fiber derived from chitin in shell-fish, is a nondigestible aminopolysaccharide. Chitosan is synthesized by removing acetyl groups from chitin, through a process called deacetylation. This process enhances the activity of chitosan by improving its solubility in the acidic environment of the stomach.