What do lobsters, fungi, and your connective tissue have in common? They all rely on N-acetylglucosamine for structure and elasticity. This molecule supports your joints, gut, nerves, and skin, but it may be dangerous under certain conditions. Read on to learn everything about N-acetyl-glucosamine and see if its benefits outweigh the risks.

What is N-Acetylglucosamine?

N-acetyl-D-glucosamine (NAG or GlcNAc) is an amino sugar derived from glucosamine. They both build chitin, the skeleton of shellfish (lobsters, shrimp, crabs) [1].

N-acetyl-glucosamine is a part of complex glycosaminoglycans, found in the cell walls of fungi and bacteria. They impregnate our skin, joints, gut lining, and connective tissue. A popular member of this family of compounds is hyaluronic acid [1].

N-Acetyl-Glucosamine vs. Glucosamine

Add acetic acid to glucosamine, and you get N-acetylglucosamine (NAG). Both glucosamine and NAG are commercially made by breaking down and modifying chitin [1].

Although both have similar structures and build the same long chains of molecules, NAG has some unique functions in the human body and potential health benefits we’ll discuss in this article.



  • Supports joint health
  • Relieves gut inflammation
  • May help with multiple sclerosis
  • Rejuvenates the skin


  • Limited clinical evidence
  • May worsen diabetes and glaucoma
  • May interact with blood thinners
  • Not suitable for people with shellfish allergies

Uses & Benefits of N-Acetylglucosamine

How It Works

Glucosamine and N-acetylglucosamine (NAG) act as the building blocks of large elastic molecules that support our connective tissues [2, 1].

As mentioned, they build glycosaminoglycans such as hyaluronic acid, giving strength and elasticity to our skin, joints, nerves, and gut surface [3, 4, 5].

NAG polymers (long chains) suppress inflammation in your body, keeping autoimmune and inflammatory diseases at bay [6, 7, 8].

N-acetylglucosamine may prevent the burst of free radicals from your immune cells and thus protect you against oxidative stress [9].

1) Helps With Joint Disorders

Glucosamine and N-acetylglucosamine (NAG) build complex elastic molecules in the cartilage that lubricate the joints and enable smooth movement. These nutrients may enhance cartilage recovery and repair the joints [2, 1].

Although the majority of research in this field has focused on glucosamine, NAG has also shown potential benefits for different joint disorders.


In osteoarthritis, cartilage thinning in large joints causes pain and restricts movement. Painkillers can ease the symptoms, but they don’t impact disease progression [10].

A combination of N-acetylglucosamine and chondroitin reduced pain and enhanced knee function in 50 people with knee osteoarthritis (12+ weeks of treatment) [11].

In rabbits with knee osteoarthritis, joint injections of N-acetyl-glucosamine (NAG) [12, 13]:

  • Stopped cartilage destruction
  • Boosted collagen production
  • Relieved joint inflammation

NAG showed better results than hyaluronic acid.

Joint Recovery

In a study on 68 volunteers, N-acetylglucosamine (500-1000 mg daily for 4 months) strengthened the cartilage by inhibiting collagen degradation [14].

Joint injections with NAG and hyaluronic acid improved tendon and bone healing in rabbits with knee injuries. NAG extracted from algae showed similar effects in rats when applied directly to their injured tendons [15, 16].

Rheumatoid Arthritis

Rheumatoid arthritis is an autoimmune disease in which joint inflammation causes pain and stiffness [17].

In mice with rheumatoid arthritis, both glucosamine and N-acetylglucosamine relieved inflammation and improved joint function [18].


Although N-acetylglucosamine may help recover the joints, we should wait for extensive clinical trials to confirm these effects and establish optimal dosage.

2) Relieves Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is another autoimmune disorder that causes severe inflammation. It attacks the gut lining and causes unpleasant digestive symptoms [19].

In a clinical trial with 36 IBD patients, N-acetylglucosamine (6 g daily for 4 weeks) improved symptoms such as pain, diarrhea, and bleeding in most cases (88%) [20].

N-acetylglucosamine showed promising effects in children with severe drug-resistant IBD.

In one study, 8 out of 12 children with IBD who received NAG orally (3 – 6 g a day) experienced notable improvement. Rectal application of NAG relieved the symptoms in 5 out of 9 children while all of them showed the signs of gut healing [21].

The above IBD clinical trials had small samples and lacked placebo controls. They indicate positive clinical experience with NAG, but we can’t draw definite conclusions from their results.

A study on gut tissue of IBD patients showed that NAG builds the layer of mucus in the bowels and combats inflammation. The gut of IBD patients failed to transform glucosamine into NAG and thus lacked this protective effect [22].

This may explain why NAG was able to silence the autoimmune response in the gut samples of IBD patients [23].

Animal studies voice the benefits. In mice with IBD, N-acetylglucosamine prevented disease progression and reduced gut inflammation [23].

3) May Help With Multiple Sclerosis

In multiple sclerosis (MS), progressive nerve damage causes an array of physical and cognitive impairments. Once again, we have autoimmune inflammation lurking as one of the culprits [24].

N-acetylglucosamine (NAG) suppressed the Th1 and Th17 autoimmune responses in mice with MS. It worked by blocking nerve inflammation (lowering IFN-gamma, TNF-alpha, IL-17, IL-22). As a result, it prevented autoimmune nerve destruction [25].

Another study on mice confirmed that the lack of NAG polymers might strip the nerve-protecting sheet, myelin, and trigger multiple sclerosis [26].

In test tubes, glucosamine and N-acetylglucosamine protected brain cells against oxidative damage and death, which may be useful in nerve-damaging diseases such as MS [27].

4) Supports Wound Healing

Polymers of N-acetylglucosamine (NAG) stimulate blood clotting, and they already found a place in different wound-healing patches and bandages [28, 29].

Units of glucosamine and NAG build chitosan, a material with potent wound-healing properties. NAG polymers have shown even better results in test tubes [30, 31, 32].

In mice, nano-fibers with N-acetylglucosamine promoted wound healing and lowered the risk of bleeding complications [33].

Hemophilia is a genetic disorder in which a person lacks specific proteins that enable blood clotting. Scientists are developing cures to prevent severe bleeding in hemophilia patients [34].

In the blood samples of dogs with hemophilia, NAG polymers enhanced blood clotting when added to standard treatment [35].

If you care about your skin health and appearance, you will love the following chapter…

Benefits of N-Acetyl-Glucosamine for the Skin

Hyaluronic acid is all the rage in skincare, and for a good reason: it’s responsible for keeping your skin soft and rejuvenated. Since N-acetylglucosamine (NAG) builds hyaluronic acid and other elastic polymers, it may [2, 1]:

  • Reduce wrinkles and other signs of aging
  • Hydrate the skin
  • Speed-up wound healing

NAG also inhibits the production of the skin pigment melanin and aids in skin lightening.

5) Removes Skin Spots

A cream with 2% N-acetylglucosamine (NAG) removed dark face spots in 2 clinical trials (200+ people). A combination of NAG and niacinamide (vitamin B3) showed even better results [36, 37].

6) Combats Skin Aging

In 42 older women, a neck and decolletage cream with N-acetylglucosamine (NAG) rejuvenated the skin and removed aging spots. Women who used the cream noticed a significant improvement in skin complexion [38].

Another clinical trial found that NAG may moisturize the skin [39].

Limitations, Side Effects, Drug Interactions & Dosage

Limitations and Caveats

We don’t have enough data to draw reliable conclusions from the research on N-acetylglucosamine (NAG). Most potential benefits are still limited to animal and cell studies.

Clinical trials with NAG are scarce and come with notable limitations, such as [11, 14, 21]:

  • Lack of placebo control
  • Small sample size
  • Involvement of other substances

That said, N-acetylglucosamine did show encouraging health effects, and it’s worth further investigation.

Side Effects

Clinical trials with N-acetyl-glucosamine (NAG) reported no major side effects [11, 14, 21].

Glucosamine and NAG are derived from glucose and may interfere with its metabolism. Clinical studies haven’t found adverse effects of glucosamine in people with controlled diabetes, but we lack such studies for NAG [40, 41, 42, 43].

Glucosamine may raise blood glucose levels in cases of uncontrolled diabetes or insulin resistance. This may not be the case with N-acetyl-glucosamine, but you should stay on the safe side and closely monitor blood glucose [44, 45].

Glucosamine supplements may increase eye pressure in the elderly and thus raise the risk of glaucoma [46, 47, 48].

Since NAG builds the same glycosaminoglycans that affect eye pressure, people at risk of glaucoma may want to avoid it [49].

Most supplement manufacturers derive NAG from shellfish and warrant caution for people with shellfish/seafood allergy. Check out the “N-Acetyl-Glucosamine Supplements” chapter for safe alternatives.

Theres not enough evidence to proclaim NAG safe for pregnant women while children should take it only under medical supervision.

Drug Interactions

Glucosamine interacts with blood thinners such as warfarin (Coumadin). Their combination may extend ones bleeding time and increase the risk of bruising [50].

Again, this doesn’t mean that N-acetylglucosamine would act the same way, but their similar structures imply this possibility.

Consult your doctor or pharmacist before taking NAG with medication and tell them everything about your current therapy.

Dosage & Supplements

The following doses of N-acetyl-glucosamine (NAG, GlcNAc) were effective in clinical trials:

  • Osteoarthritis: 100 mg/day for 12+ weeks (with chondroitin) [11]
  • Joint recovery: 500 – 1,000 mg/day for 16 weeks [14]
  • IBD (children): 3 – 6 g/day [21]
  • Skin spots: a cream with 2% NAG (+ 4% niacinamide) for 8 weeks [36, 37]

Most supplements on the market contain caps with 500 1,000 mg of N-acetylglucosamine.

Watch out! Some products claim to have vegetarian/vegan caps, but they source NAG from shellfish. If you have a shellfish/seafood allergy or avoid animal products, look for the products with NAG from vegan sources.

Bulk powders with 750 mg of NAG per serving are also available.

Reviews & User Experiences

Users take N-acetylglucosamine (NAG) for joint pain, IBD, and skincare, and most of them are satisfied with the result. Interestingly enough, some users reported the benefits of N-acetylglucosamine for anxiety and multiple sclerosis.

There are people with osteoarthritis and gut inflammation who experienced no improvement from NAG supplements. Some of them even complained about digestive side effects and worsened asthma.


  • Amazon (oral supplement in combination with pro- and prebiotics)
  • Amazon (NAG with vitamin B3 for making your own skincare solutions/creams)
  • iHerb (pure NAG capsules)
  • iHerb (NAG combination supplement for gut health and celiac support)

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N-acetylglucosamine (NAG or GlcNAc) builds large elastic molecules that support your joints, skin, and connective tissue.

It boosts joint health, relieves gut inflammation, and rejuvenates the skin. It may also help with multiple sclerosis and other nerve-damaging diseases. However, clinical evidence remains limited.

NAG may not be suitable for people with diabetes and glaucoma, pregnant women, and people on blood thinners. Those with shellfish/seafood allergy should look for NAG from vegan sources.

About the Author

Aleksa Ristic, MSc (Pharmacy)

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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