Uses

Chitosan is a polysaccharide found in the shells of crustaceans.

What Are Star Ratings?

This supplement has been used in connection with the following health conditions:

Used for Why
2 Stars
Obesity
Refer to label instructions
Chitosan is a fiber-like substance that may reduce fat absorption. One study found it to be an effective weight-loss aid.
Chitosan is a fiber-like substance extracted from the shells of crustaceans such as shrimp and crab. Animal studies suggested that chitosan supplementation reduces fat absorption, but controlled human trials have found no impairment of fat absorption from supplementation with 2,700 mg of chitosan per day for seven days or 5,250 mg per day for four days. A double-blind study found that people taking 1,500 mg of chitosan three times per day during a weight-loss program lost significantly more weight than did people taking a placebo with the same program. Similar benefits were seen in another double-blind study that used 3,000 mg of chitosan per day. Other studies using smaller amounts of chitosan have reported no effects on weight loss.
1 Star
High Cholesterol
Refer to label instructions
Chitosan is a fiber-like supplement that has been shown to lower cholesterol and raise HDL ("good") cholesterol).

The fiber-like supplement chitosan appears to reduce the absorption of bile acids or cholesterol; either of these effects may cause a lowering of blood cholesterol. This effect has been repeatedly demonstrated in animals, and a preliminary human study showed that 3 to 6 grams per day of chitosan taken for two weeks resulted in a 6% drop in cholesterol and a 10% increase in HDL ("good") cholesterol. Another preliminary trial showed a 43% lowering of total cholesterol in people being treated for kidney failure with dialysis who took 4 grams per day of chitosan for 12 weeks. These people also appeared to have improved kidney function and less severe anemia after chitosan treatment. In a double-blind trial, however, administration of 2.4 grams of chitosan per day for three months to people with high cholesterol had no effect on their cholesterol levels. Another study also found no cholesterol-lowering effect of chitosan when taken in amounts up to 6.75 grams per day for 8 weeks.

Chitosan in large amounts, given with vitamin C, has been shown to reduce dietary fat absorption in animals fed a high-fat diet. However, the absorption of minerals and fat-soluble vitamins was also reduced by feeding animals large amounts of chitosan. In studies in humans, chitosan did not reduce the absorption of dietary fat.

How It Works

How to Use It

Most human research has used 3-6 grams per day with meals.

Where to Find It

Chitosan is extracted from the shells of crustaceans, such as shrimp and crab.

Possible Deficiencies

Chitosan is not an essential nutrient, so deficiencies do not occur.

Interactions

Interactions with Supplements, Foods, & Other Compounds

While no long-term studies of the effects of chitosan on human health have been done, animal studies suggest that this compound could inhibit the absorption of minerals and fat-soluble vitamins.

Interactions with Medicines

As of the last update, we found no reported interactions between this supplement and medicines. It is possible that unknown interactions exist. If you take medication, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.
The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers' package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a supplement with your doctor or pharmacist.

Side Effects

Side Effects

Adverse effects on the growth of children and on the outcome of pregnancy are possible.1 In addition, although chitosan-included alterations in intestinal flora are believed to be beneficial, the possibility that these changes may have negative long-term consequences has not been ruled out. People with intestinal malabsorption syndromes should not use chitosan.

References

1. Koide SS. Chitin-chitosan: properties, benefits and risks. Nutr Res 1998;18:1091-101 [review].