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Chitosan For Weight Loss + Benefits, Reviews & Precautions

Written by Aleksa Ristic, MS (Pharmacy) | Last updated:
Jonathan Ritter
Puya Yazdi
Medically reviewed by
Jonathan Ritter, PharmD, PhD (Pharmacology), Puya Yazdi, MD | Written by Aleksa Ristic, MS (Pharmacy) | Last updated:

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Shellfish

Chitosan is a natural glucosamine polymer derived from shellfish. People use it to enhance weight loss, lower cholesterol, improve skin health, and more. Recent research casts doubt on some of these uses, but opens the door to other important applications in skin care, medicine, and technology. Read on to learn the benefits & uses of chitosan, along with safety precautions.

What Is Chitosan?

Chitin is a biodegradable fiber most commonly derived from the outer shells of shrimp and other shellfish. It is also found in the skeletons of insects and fungi. Some even call chitin “nature’s armor” due to its extreme resilience and robustness [1].

Chitin can be modified into a couple of forms, including [1]:

  • Chitosan (including pills, hydrogels, nanoparticles, and bandages)
  • Chitosan oligosaccharide

Chitosan is a processed form of chitin. Chitin is made up of hard and highly insoluble chains of N-acetylglucosamine. Chitosan, on the other hand, is more soluble is mostly made up of glucosamine chains [2, 3].

Unlike chitin, chitosan completely lacks irritant or allergic properties and is highly compatible with human skin – unique properties that gave rise to chitosan bandages [2].

Chitosan oligosaccharide is prepared by further modifying chitosan and breaking its large chains into smaller ones. It offers several advantages over both chitin and chitosan: much better solubility, lower viscosity, increased bioavailability, and superior benefits [2, 3].

But there’s a drawback.

The process of producing chitosan oligosaccharide is complex and hard to fully control. Other compounds and impurities can sneak into the final product during manufacturing. That’s why chitosan oligosaccharide supplements are harder to find and usually more expensive [2].

Snapshot

PROs

  • May boosts weight loss
  • May reduce cholesterol and blood pressure
  • Gels and bandages speed up wound healing
  • May enhance skin health

CONs

  • Reduces the absorption of minerals and fat-soluble vitamins
  • May cause indigestion
  • May block the activity of certain medications
  • Not suitable for people with shellfish or seafood allergies

How Does Chitosan Work?

Chitosan works in more than one way, which is reflected in its diverse uses.

For starters, it’s used in healthcare, cosmetics, dentistry, and for targeted drug delivery.

Its durability and unique chemical structure grant chitosan potential health benefits. People mostly use it for enhancing weight loss and lowering cholesterol, but it can also form protective films on damaged skin and aid its healing.

What makes chitosan so special?

Most of its different uses span from its physical properties: chitosan is a “biopolymer” – it forms a network of tightly bound large molecules that provide mechanical integrity [2].

Binding Fats

Chitosan is a non-digestible dietary fiber. When consumed, its network of large molecules binds to toxins, fats, and cholesterol in the gut. These get carried out of the gut and removed with the stool.

In other words, chitosan may reduce the absorption of fats and toxins in your gut by binding to them, a mechanism observed in rat studies [4].

Its ability to bind excess fats is thought to underlie its weight loss action as well.

Regenerating the Skin

When chitosan is applied to the skin, it frees active compounds that reduce inflammation and enhance rejuvenation.

In cells, chitosan lowered the action of several inflammatory compounds (such as IL-1b); it also increased the action of anti-inflammatory ones, such as IL-10 – a cytokine essential for skin regeneration and wound healing [5, 6].

Health Benefits of Chitosan

Possibly Effective:

1) Wound Healing & Surgery Recovery

Chitosan gels can help speed up wound healing and aid in surgery recovery. In a meta-analysis of three clinical studies, chitosan gel dressing reduced swelling and helped stop bleeding after sinus surgery. The dressing did not influence crusting or infections [7].

In 25 patients, a gel with chitosan, 0,2% chlorhexidine, allantoin, and dexpanthenol enhanced wound healing after third molar extraction. However, it didn’t relieve postoperative discomfort [8].

In one study, topical chitosan stimulated collagen production, increased the local immune response, encouraged tissue regeneration, and prevented scarring [9].

2) High Blood Pressure

Researchers have been studying chitosan as a binding agent for table salt for the management of high blood pressure (hypertension).

In two trials of 81 patients with prehypertension or moderate hypertension, taking a specific product (Symbiosal) with 3% chitosan in table salt for 8 weeks decreased systolic blood pressure, compared with table salt alone [10, 11].

Insufficient Evidence:

No valid clinical evidence supports the use of chitosan for any of the conditions in this section. Below is a summary of up-to-date animal studies, cell-based research, or low-quality clinical trials which should spark further investigation. However, you shouldn’t interpret them as supportive of any health benefit.

3) Weight Loss

Chitosan forms connective films, attaching to bile and fatty acids in the gut. The films then pass through your digestive system, potentially increasing the amount of fat removed in the stool [12, 13].

In one clinical study, chitosan supplements reduced participants’ weight by up to ~7 lbs over three months. But placebo alone helped people lose up to 4 lbs. In turn, chitosan’s realistic contribution was only about 3 lbs (1.36 kg), on average [14].

A Cochrane database review included 15 clinical trials of 1,219 total participants. Chitosan supplementation slightly improved weight loss (‐1.7 kg on average). However, this review failed to confirm increased fat excretion. The authors concluded that “the effect of chitosan on body weight is minimal and unlikely to be of clinical significance” [15].

Even if chitosan did bind and remove dietary fats, there’s a potential downside to this effect. By attaching to and enhancing the removal of excess fats, it may also increase the elimination of important minerals such as calcium and fat-soluble vitamins like vitamin D and vitamin A [16].

Further clinical trials should investigate long-term safety and efficacy of chitosan supplements for weight loss.

4) High Cholesterol

According to a review of human studies, adding chitosan to a regular diet can lower total blood cholesterol levels by ~6-40% and LDL cholesterol levels by 15 – 35% [12].

In one trial of 84 women, chitosan worked to lower total cholesterol levels better than placebo. In a subgroup of women over 60 years of age, it also reduced LDL and total cholesterol [17].

On the other hand, chitosan failed to improve cholesterol levels in three studies of 247 participants in the absence of dietary changes [18, 19, 20].

It may be a safe option for people with borderline-high cholesterol levels, along with appropriate dietary and lifestyle changes. More research is needed.

5) Kidney Disease

Chitosan supplements may help people with kidney disease or kidney failure, but the research to-date is sparse.

In one older trial, chitosan given to 40 people with kidney failure improved strength, appetite, and sleep after 12 weeks. It also increased hemoglobin and reduced blood creatinine and urea levels, which points to its potential to improve kidney function [21].

Additionally, high phosphorus levels are strongly linked with a higher risk of dying in people with chronic kidney disease. In rats, an iron-chitosan complex reduced blood phosphorus levels. This complex can bind phosphorus stronger than most other available phosphorus binders [22, 23, 24].

Chitosan Chewing Gum

Chewing chitosan gum also became a popular method for reducing high phosphate levels in people with kidney disease.

However, chitosan gum is not as good as it sounds. In fact, it is probably downright ineffective.

One 2009 study found that chitosan gum lowered phosphate levels after just two weeks of chewing. Recent studies failed to replicate the results [25].

It turns out that the amount of chitosan in chitosan chewing gum is too low to have a phosphate-binding effect. And according to a detailed analysis, the 2009 study was poorly designed, while the benefits boil down to a placebo effect [25].

6) Oral Health

More recently, chitosan found its way into dentistry and oral health.

It can be formulated into products for fighting cavities and boosting oral health. Some people chew chitosan gum to prevent or reduce gum inflammation, though no studies confirmed their effectiveness.

In one clinical study, a chitosan mouth-rinse reduced plaque build-up and bacterial growth that leads to gum disease [26, 27].

Chitosan’s microbe-fighting effects in humans are still an active area of research.

Animal and Cellular Research (Lacking Evidence)

No clinical evidence supports the use of chitosan for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based studies; they should guide further investigational efforts but should not be interpreted as supportive of any health benefit.

Fatigue

Chitosan oligosaccharides decreased fatigue in sleep-deprived rats. It also curbed other undesirable fatigue-triggered effects, such as weight loss and immobility [28, 29].

Additionally, chitosan lowered excess levels of the stress hormone cortisol in fatigued mice and raised their levels of an important antioxidant called superoxide dismutase (SOD) [30, 29].

Inflammation

Chitosan oligosaccharide might reduce inflammation, but clinical trials are still lacking [31, 5].

In rats, this oligosaccharide lowered inflammation in the brain, suppressing the release of inflammatory cytokines (such as IL-1b and TNF-alpha) [32].

In cells, it blocked inflammation caused by a bacterial toxin – LPS (by lowering IL-6). LPS can trigger a strong inflammatory response and may sneak into the blood in people with leaky gut [33].

Crohn’s Disease and Leaky Gut

There is a strong link between inflammatory cytokines such as IL-1b and TNF-alpha and Crohn’s disease. High levels of these cytokines may increase cell death (apoptosis) in the gut, compromising the gut’s integrity and possibly leading to what is commonly called leaky gut [34].

According to animal studies, chitosan oligosaccharide may improve IBD symptoms (including Crohn’s) and reduce the death of gut cells. This effect may help strengthen the gut barrier [35, 34].

In another recent study, piglets eating a chitosan oligosaccharide-enhanced diet experienced reduced gut inflammation [36].

Brain Protection

Chitosan oligosaccharide may have some brain-protective properties. Supplementation with the oligosaccharide form reduced brain damage in rats with Alzheimer’s and improved their memory and learning [32, 37].

Additional research is underway, exploring its potential to prevent Alzheimer’s and Parkinson’s disease [38, 39, 40, 41].

Binding Toxins & Heavy Metals

Chitosan might bind to and help remove toxins. Since it eliminates bacteria (such as E.coli) and heavy metals from water, similar benefits from supplements are a possibility. Despite this, its effects on clearing toxins in humans have yet to be explored [42, 43].

In rats, chitosan protected against the buildup of a toxic heavy metal called cadmium. It reduced cadmium levels and protected the animals against damage [44].

In one cell-based study, chitosan could bind to and filter out mold toxins [45].

Effects on Cancer (Limited Evidence)

The effects of chitosan on cancer are still unclear.

On the one hand, it activates genes that help destroy damaged cells that could develop into cancer [46, 47, 48].

On the other hand, chitosan triggered the growth of liver and colon cancer stem cells in test tubes. These effects have not been observed in animals or humans [49].

Lastly, chitosan can also be used to deliver cancer drugs. Medications latch onto its large matrix of molecules and are carried through the body until arriving at the intended delivery site [50].

Limitations and Caveats

  • Many chitosan studies have only been carried out in animals.
  • Most clinical studies were short-term, their duration ranging from 4 to 16 weeks. The long-term effects of chitosan are unknown.
  • Many benefits are still debated and insufficiently researched [51]

Chitosan Bandages

Chitosan is an excellent natural material for making bandages. It has all the following benefits:

  • Stops or slows down excessive bleeding
  • Reduces the risk of infection
  • Reduces inflammation
  • Non-toxic and compatible with skin
  • Releases glucosamine to aid skin repair

Chitosan bandages are used by the military, in trauma care, and during surgery as wound dressings [52, 53].

Bandages can also be made from a combination of chitosan, honey, and gelatin. These are applied to burns to assist healing and encourage skin regeneration [54].

Chitosan with Glucomannan

Chitosan supplements sometimes come with glucomannan, a dietary fiber commonly taken to promote weight loss. Since chitosan increases fat elimination, it makes sense to assume that this combo might further encourage fat loss.

In one clinical study, their combination reduced cholesterol levels in overweight people [55].

At the same time, this study casts doubt on the ability of chitosan and glucomannan to boost weight loss. Researchers revealed the combination only helps remove cholesterol-like compounds and bile acids, but not fats in general [55].

Advanced Formulations

Scientists are using chitosan to create gels that may help deliver complex immune compounds to tissues.

In one cell-based study, chitosan gels were used as a carrier for a protein called Transforming Growth Factor Beta 1 (TGF-β1). This protein increased the growth of stem cells in the bone marrow and encouraged them to develop into cartilage and joint cells that help rebuild connective tissue after injury [56].

As it turns out, chitosan formulations like this one may pave the way to a new era of regenerative medicine.

Chitosan alone, however, won’t have this effect.

Chitosan For Cats and Dogs

Chitosan gels and bandages are likely safe in cats and dogs.

Applied to the skin, chitosan improved wound healing in over 140 types of animals, including cats and dogs. It enhanced the growth of new connective tissue and blood vessels, while it may also increase collagen production and minimize scarring [57, 58, 59].

Veterinarians should be cautious when applying chitosan to large open wounds in animals. High doses can be absorbed into the bloodstream and may cause possibly deadly pneumonia in dogs [57, 60].

Chitosan Side Effects & Precautions

Chitosan is considered GRAS by the FDA, meaning that it is “generally recognized as safe” [61].

Those with a shellfish allergy should avoid chitosan supplements to stay on the safe side.

In animal studies, chitosan was exceptionally safe. However, only a few clinical trials have been carried out [62].

Chitosan supplements may decrease mineral absorption and bone mineral content and cause mild nausea and constipation [12, 62].

Chitosan bandages for bleeding control seem to be safe for children [63].

However, children and pregnant or breastfeeding women should avoid chitosan pills due to the lack of safety data.

Drug Interactions

Supplement-drug interactions can be dangerous and, in rare cases, even life-threatening. Always consult your doctor before supplementing and let them know about all drugs and supplements you are using or considering.

Chitosan may reduce the effectiveness of some drugs. The following interactions are possible:

  • Reduced absorption of fat-soluble drugs, including birth control pills.
  • Reduced vitamin K levels and increased blood-thinning effects of warfarin (Coumadin), possibly causing excessive bruising and bleeding [64].
  • Reduced absorption of an antiviral drug acyclovir [65].

Chitosan Supplements & Dosage

Chitosan supplements come in a few forms, from capsules and powders to gels and bandages. Here is a brief overview of all the formulations.

Oral supplements

Chitosan oral supplements are usually made from shellfish-derived powder packed into veggie caps. Dosages range from ~700 mg per serving to 1,800 mg per serving.

Some companies sell chitosan as a liquid oral spray, pressed tablets or loose powder (you can even pack it into veggie capsules yourself).

All these are sold as either chitin, chitosan, chitosan oligosaccharide, or their combination. Chitosan oligosaccharide is more soluble than chitin or chitosan [66].

Chitosan Bandages

Chitosan bandages on the market are designed to stop bleeding rapidly and to provide antiseptic protection.

Bandages come as gauze pads, emergency compression bandages, wound dressings, and occasionally as liquid bandages in a spray bottle (these are marketed primarily for veterinary use).

There are few things to consider when it comes to choosing a bandage. Some bandages “gel up” when used to further accelerating blood-clotting. The highest-quality bandages on the market are made of 100% chitosan while other bandages simply have added chitosan fibers.

Prices range from approximately $8 a bandage to upwards of $35+ for high-quality wound dressing rolls. A box with 50 gelling bandages sells online for $56.

Chitosan Gels

Chitosan gels and sprays are marketed for a variety of purposes.

The gels are usually formulated to speed up wound healing, while nasal sprays are meant to help relieve dryness and sinus inflammation.

Chitosan is also added to skincare moisturizers formulated with collagen to support anti-aging action.

Dosage

The below doses may not apply to you personally. If your doctor suggests using a grape seed extract supplement, work with them to find the optimal dosage according to your health condition and other factors.

The most common chitosan dosage for lowering cholesterol and supporting weight loss in clinical trials was ~2.4 g/day [12, 15].

User Reviews & Experiences

The opinions expressed in this section are solely from the users who may or may not have a medical background. SelfDecode does not endorse any specific product, service, or treatment. Do not consider user experiences as medical advice. Never delay or disregard seeking professional medical advice because of something you have read on SelfDecode.

In a video review, one pharmacist shared his experience and success with chitosan. He highly recommends it for boosting collagen production and enhancing wound healing. Additionally, he references its anti-aging and anti-inflammatory benefits, along with its potential to improve IBD.

One user reported taking chitosan as a fiber supplement, stating that it’s a great option to support weight loss goals.

Yet another person suggested that chitosan works excellently as an appetite suppressant. She says it has helped her lose weight and reduce food cravings. Another says she takes it as-needed when consuming fattier meals and has found it to be effective.

On the downside, one web user found that chitosan supplementation gave her an upset stomach and had questionable results otherwise.

One online user made a video review. In it, he says chitosan improved his blood sugar levels, regulated his bowel movements, and improved his weight loss efforts, stating that he lost 10 lbs with its help.

Takeaway

Chitosan is derived from chitin, a unique natural polymer of glucosamine molecules. It may reduce blood pressure and support wound healing. Some people use chitosan to boost fat loss and lower cholesterol by preventing their absorption, but the evidence is limited.

Applied to the skin, chitosan forms protective films, stops bleeding, reduces inflammation, and enhances regeneration. An emerging area of research is using chitosan to make natural implants and deliver targeted drugs.

On the downside, chitosan can also bind to minerals and fat-soluble vitamins, possibly reducing their levels in the body. It can also attach to drugs and reduce their effectiveness. Consult your healthcare provider before supplementing if you take medications.

About the Author

Aleksa Ristic

Aleksa Ristic

MS (Pharmacy)
Aleksa received his MS in Pharmacy from the University of Belgrade, his master thesis focusing on protein sources in plant-based diets. 
Aleksa is passionate about herbal pharmacy, nutrition, and functional medicine. He found a way to merge his two biggest passions—writing and health—and use them for noble purposes. His mission is to bridge the gap between science and everyday life, helping readers improve their health and feel better.

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