Related Terms

• Absorbitol®, carboxybutyl chitosan, chitin, chitosan ascorbate, deacetylated chitin biopolymer, deacetylated chitosan, enzymatic polychitosamine hydrolisat, Exofat™, Fat Absorb™, Fat Blocker™, Fat Breaker™, Fatsorb™, Fat Trapper™, Fat Trapper Plus™, Fronac N™, glucosamine, HEP-30, kitosan, LipoSan Ultra™,microcrystalline chitosan, mono-carboxymethylated chitosan, N-acetylated glucosamine, Nofat®, Novamic™, Somagril®, sulfated carboxymethylchitosan, sulfated chitosan, sulfated N-acetylchitosan, trimethyl chitosan chloride.

Background

• Chitosan comes from chitin, which is part of the outer shell-like structure of insects, spiders, and crustaceans.

• Chitosan is sold in the United States and other countries as a form of dietary fiber that reduces fat absorption. However, scientific evidence suggests only a small effect of chitosan on fat absorption.

• Chitosan may be effective for lowering levels of blood cholesterol or lipids. Whether the use of chitosan is equal to or better than other treatments for high cholesterol is not yet known. Study results suggest that chitosan may help improve cholesterol levels when combined with a low-calorie diet.

• Some evidence indicates that chitosan may be useful for patients undergoing hemodialysis for kidney failure and in the management of dental plaque. More evidence is needed to confirm these results.

Scientific Evidence

Tradition/Theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.

• Antacid, antimicrobial, appetite suppressant, arthritis, blood clotting disorders, cancer, chlamydia, diabetes mellitus, heart disease, high blood pressure, HIV, immune function, infections, leukemia, nerve regeneration, physical endurance, sleep.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

• Doses of chitosan include: 1 to 6 grams daily for up to 8 weeks, and 450 milligrams three times daily for up to 12 weeks. Chitosan has been applied to the skin for 3 to 6 months.

Children (under 18 years old)

• There is no proven safe or effective dose for chitosan in children.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

• Avoid with known allergy or hypersensitivity to chitosan, its constituents, chitin, or crustaceans. People with shellfish allergies may be allergic to chitosan.

Side Effects and Warnings

• Chitosan may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a qualified healthcare professional, and medication adjustments may be necessary.

• Chitosan may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or in patients taking drugs, herbs, or supplements that may increase the risk of bleeding. Dosing adjustments may be necessary.

• Chitosan may cause stomach discomfort, constipation, gas, diarrhea, nausea, and throat dryness. Chitosan may interfere with fat absorption from the intestine, causing excessive fat to be lost in the stool, and may reduce absorption of the fat-soluble vitamins A, D, E, and K. Chitosan may also cause headache, swollen heels and wrists, and itching of the skin.

Pregnancy and Breastfeeding

• Chitosan is not recommended in pregnant or breastfeeding women due to a lack of available scientific evidence. Chitosan may reduce absorption of calcium and vitamin D.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

• Chitosan may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or in patients taking drugs that may increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).

• Chitosan may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. Patients taking drugs for diabetes by mouth or injection should be monitored closely by a qualified healthcare provider. Medication adjustments may be necessary.

• Chitosan may have additive effects when used with cholesterol-lowering, anti-obesity, or antibiotic drugs. Chitosan may also slow the absorption of oral contraceptives.

Interactions with Herbs and Dietary Supplements

• Chitosan may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.

• Chitosan may increase the risk of bleeding. Caution is advised in patients taking herbs or supplements that may increase the risk of bleeding.

• Chitosan may have additive effects when used with cholesterol-lowering, anti-obesity, or antibiotic herbs and supplements.

• Use of chitosan may decrease the absorption of calcium, magnesium, selenium, essential fatty acids, fat-soluble vitamins A, D, E, and K, and may also slow the absorption of oral contraceptives. Use of chitosan with vitamin C may decrease fat absorption.

Author Information

• This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

1. Aiedeh K, Gianasi E, Orienti I, Zecchi V. Chitosan microcapsules as controlled release systems for insulin. J Microencapsul. 1997;14(5):567-576. View Abstract

2. Aspden TJ, Mason JD, Jones NS, et al. Chitosan as a nasal delivery system: the effect of chitosan solutions on in vitro and in vivo mucociliary transport rates in human turbinates and volunteers. J Pharm Sci 1997;86(4):509-513. View Abstract

3. Bokura H, Kobayashi S. Chitosan decreases total cholesterol in women: a randomized, double-blind, placebo-controlled trial. Eur J Clin Nutr. 2003;57(5):721-725. View Abstract

4. Ernst E, Pitter MH. Chitosan as a treatment for body weight reduction? A meta-analysis. Perfusion 1998;11(11):461-465.

5. Gades MD, Stern JS. Chitosan supplementation does not affect fat absorption in healthy males fed a high-fat diet, a pilot study. Int J Obes Relat Metab Disord. 2002;26(1):119-122. View Abstract

6. Girola M, De Bernardi M, Contos S, et al. Dose effect in lipid-lowering activity of a new dietary integrator (chitosan, Garcinia cambogia extract, and chrome). Acta Toxicol Ther 1996;17:25-40.

7. Guerciolini R, Radu-Radulescu L, Boldrin M, et al. Comparative evaluation of fecal fat excretion induced by orlistat and chitosan. Obes Res. 2001;9(6):364-367. View Abstract

8. Illum L, Jabbal-Gill I, Hinchcliffe M, et al. Chitosan as a novel nasal delivery system for vaccines. Adv Drug Deliv Rev 9-23-2001;51(1-3):81-96. View Abstract

9. Jing SB, Li L, Ji D, et al. Effect of chitosan on renal function in patients with chronic renal failure. J Pharm Pharmacol 1997;49(7):721-723. View Abstract

10. Koide SS. Chitin-chitosan: properties, benefits and risks. Nutrition Research 1998;8(6):1091-1101.

11. Mhurchu CN, Poppitt SD, McGill AT, et al. 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;28(9):1149-1156. View Abstract

12. Sawayanagi Y, Nambu N, Nagai T. Use of chitosan for sustained-release preparations of water-soluble drugs. Chem Pharm Bull (Tokyo) 1982;30(11):4213-4215. View Abstract

13. Thanou M, Verhoef JC, Junginger HE. Oral drug absorption enhancement by chitosan and its derivatives. Adv Drug Deliv Rev. 11-5-2001;52(2):117-126. View Abstract

14. Uchegbu IF, Schatzlein AG, Tetley L, et al. Polymeric chitosan-based vesicles for drug delivery. J Pharm Pharmacol 1998;50(5):453-458. View Abstract

15. Veneroni G, Veneroni F, Contos S, et al. Effect of new chitosan dietary integrator and hypocaloric diet on hyperlipidemia and overweight in obese patients. Acta Toxicol Ther 1996;17:53-70.