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Common Name(s)

Chitosan, chitin

Medically reviewed by Last updated on Mar 8, 2019.

What is Chitosan?

Chitin is a cellulose-like biopolymer found mainly in the exoskeleton of marine animals such as shrimp, crabs, or lobsters. Chitin can also be found in mushrooms and yeasts. Chitosan is a chemically processed form of chitin. "Squid pens," waste shell by-products of squid processing, are a renewable and inexpensive source of chitosan.

What is it used for?

Traditional/Ethnobotanical uses

Chitosan has been used in water purification plants to absorb greases, oils, metals, and toxic substances. Chitosan has been used in the cosmetic and fabric industry.

General uses

There is some evidence of the effect of chitosan on lowering cholesterol and body weight, but the effect is unlikely to be of medical importance. Chitosan dressings are sometimes used in emergency rooms to control bleeding. Chitosan has been used in various drug delivery systems. Antimicrobial and other effects are being evaluated for use in dentistry.

What is the recommended dosage?

Chitosan has been administered at wide-ranging doses in clinical studies. In studies evaluating weight loss, 2.4 g/day is commonly used.


None well established.


Information regarding safety and efficacy in pregnancy and lactation is lacking.


Data are limited. Potentiation of the anticoagulant effect of warfarin was reported in a patient receiving chitosan 2.4 g/day.

Side Effects

The potential for allergy exists in individuals allergic to shellfish. Clinical trials report few adverse events, generally limited to flatulence and constipation.


Chitosan's toxicity profile is relatively low.


1. Chitosan. Review of Natural Products. Facts & Comparisons Online. March 2010. Accessed April 20, 2010.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.