Does Chitosan Really Help You Lose Weight?

Does Chitosan Really Help You Lose Weight?

To my blog readers, I apologize in the delay in getting this particular blog post submitted.  Not surprisingly, my posts about dietary supplement ingredients which have potential benefits in terms of promoting weight loss are consistently the most viewed blog posts on my site.  Continue reading to learn more about the very popular dietary supplement for weight loss, Chitosan.

Though many of us already realize that there’s no substitute for a calorie-reduced diet and exercise in terms of promoting healthy weight loss, many of us find the temptation of a ‘quick fix’ or ‘diet’ pill to be irresistible.

In fact, I’ve recently read that “Alli” is one of the ten most popular health-related search terms.  (Alli is an FDA approved, over-the-counter weight loss product from GlaxoSmithKline).  Overweight and obesity are common health concerns not only in the United States–but globally as well.

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Does Chitosan Help with Weight Loss?

Chitosan is a dietary supplement ingredient which is found in supplements which are intended to promote weight loss and is widely available worldwide.   Other potential benefits on Chitosan include a possible reduction in cholesterol from taking the supplement.

  • A recent systematic review found that Chitosan did produce statistically significant weight loss in comparison to placebo
  • Though statistically significant, the weight loss was minimal and unlikely to be of clinical significance.

How Does Chitosan Work?

Chitosan is a partially deacetylated polymer of N-acetyl glucosamine which is derived from the polysaccharide chitin.  In animal models, it appears to bind to negatively charged lipids and therefore reducing their gastrointestinal update.

Okay, Now Does Chitosan Actually Work?

A recent systematic review of 15 individual randomized controlled trials comparing the weight loss results from Chitosan use vs. placebo in 1219 participants was published in the Cochrane Database of Systematic Reviews (Jull et al, 2008).

Note: Dosage of Chitosan in studies: range from 0.24 g/day to 15 g/day (mean 3.7 g/day)


  • Body weight:  -0.9kg (chitosan alone, p=0.0009)  when used with other weight loss agents [-2.7kg, p=0.0008]
  • Body mass index:  -0.4kg/m2  [p=.0005]
  • Total cholesterol:  -0.21 mmol/l  [p<0.00001]
  • Systolic blood pressure:  -6mm Hg [P<0.00001]

Chitosan Side Effects

[only 2/15 studies found these to be significantly increased when compared to placebo]

  • constipation
  • nausea
  • bloating
  • abdominal pain


In terms of weight loss, this systematic review did find that Chitosan produced statistically significant weight loss when compared to placebo.  However, the actual amount of weight loss was 0.6kg achieved over trial periods ranging from four weeks to six months.  However, the amount of weight loss was greater when Chitosan was used with other weight loss dietary supplements.  Further, Chitosan did produce statistically significant reductions in total cholesterol, LDL cholesterol, Systolic, and Diastolic blood pressure.  Future trials are required of better quality including more information on the dose and composition of Chitosan used.

  • Better quality trials are required with more information on dosage and composition of Chitosan
  • Chitosan supplementation did produce statistically significant reductions in total cholesterol and blood pressure
  • Chitosan supplementation did result in statistically significant weight loss–but the actual amount of weight loss unlikely to be of clinical significance (0.6kg)


  1. Jull AB, Ni Mhurchu C, Bennett DA, Dunshea-Mooij CA, Rodgers A. Chitosan for overweight or obesity.  Cochrane Database Syst Rev. 2008 Jul 16;(3):CD003892.
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