N-Acetylglucosamine (N-acetyl-D-glucosamine, or GlcNAc,) is a monosaccharide and a derivative of glucose. It is part of a biopolymer in the bacterial cell wall, built from alternating units of GlcNAc and N-acetylmuramic acid (MurNAc), cross-linked with oligopeptides at the lactic acid residue of MurNAc. This layered structure is called peptidoglycan (formerly called murein). GlcNAc is the monomeric unit of the polymer chitin, which forms the outer coverings of insects and crustaceans. It is the main component of the radulas of mollusks, the beaks of cephalopods, and a major component of the cell walls of most fungi. It is lnsown, that the breakdown of glycosaminoglycans is an important consequence of inflammation at mucosal surfaces, and inhibition of metalloprotease activity may be effective in treating chronic inflammation. GlcNAc directly incorporates into glycosaminoglycans and glycoproteins, as a substrate for tissue repair mechanisms. It was shown, that GlcNAc was promising substance for treatment of chronic inflammatory bowel disease, with a mode of action which is distinct from conventional treatments. In experiments on rabbits with osteoarthritis, was found chondroprotective effects of aminomonosaccharide glucosamine, but no statistically significant difference was found between study groups. It was also investigated for the treatment of Multiple sclerosis, however, as a drug development target, GlcNAc had significant limitations. GlcNAc has poor membrane permeability, requiring high concentrations for biological effects.

Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of the polysaccharides chitosan and chitin, which compose the exoskeletons of crustaceans and other arthropods, as well as the cell walls of fungi and many higher organisms. Glucosamine is one of the most abundant monosaccharides. It is produced commercially by the hydrolysis of crustacean exoskeletons or, less commonly, by fermentation of a grain such as corn or wheat. Oral glucosamine is a dietary supplement and is not a pharmaceutical drug. It is illegal in the US to market any dietary supplement as a treatment for any disease or condition. Glucosamine is marketed to support the structure and function of joints, and the marketing is targeted to people suffering from osteoarthritis. Commonly sold forms of glucosamine are glucosamine sulfate, glucosamine hydrochloride, and N-acetylglucosamine. Of the three commonly available forms of glucosamine, only glucosamine sulfate is given a "likely effective" rating for treating osteoarthritis. Glucosamine is often sold in combination with other supplements such as chondroitin sulfate and methylsulfonylmethane. Glucosamine, along with commonly used chondroitin, is not routinely prescribed to treat people who have symptomatic osteoarthritis of the knee, as there is insufficient evidence that this treatment is helpful. One clinical study over three years showed that glucosamine in doses of 1500 mg per day is safe to use. Glucosamine with or without chondroitin elevates the international normalized ratio (INR) in individuals who are taking the blood thinner, warfarin. It may also interfere with the efficacy of chemotherapy for treating cancer symptoms. Adverse effects may include stomach upset, constipation, diarrhea, headache, and rash. There are case reports of people who have chronic liver disease and a worsening of their condition with glucosamine supplementation. Glucosamine is naturally present in the shells of shellfish, animal bones, bone marrow, and fungi. D-Glucosamine is made naturally in the form of glucosamine-6-phosphate, and is the biochemical precursor of all nitrogen-containing sugars. Specifically in humans, glucosamine-6-phosphate is synthesized from fructose 6-phosphate and glutamine by glutamine—fructose-6-phosphate transaminase as the first step of the hexosamine biosynthesis pathway. The end-product of this pathway is uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), which is then used for making glycosaminoglycans, proteoglycans, and glycolipids. As the formation of glucosamine-6-phosphate is the first step for the synthesis of these products, glucosamine may be important in regulating their production; however, the way that the hexosamine biosynthesis pathway is actually regulated, and whether this could be involved in contributing to human disease remains unclear.

Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of the polysaccharides chitosan and chitin, which compose the exoskeletons of crustaceans and other arthropods, as well as the cell walls of fungi and many higher organisms. Glucosamine is one of the most abundant monosaccharides. It is produced commercially by the hydrolysis of crustacean exoskeletons or, less commonly, by fermentation of a grain such as corn or wheat. Oral glucosamine is a dietary supplement and is not a pharmaceutical drug. It is illegal in the US to market any dietary supplement as a treatment for any disease or condition. Glucosamine is marketed to support the structure and function of joints, and the marketing is targeted to people suffering from osteoarthritis. Commonly sold forms of glucosamine are glucosamine sulfate, glucosamine hydrochloride, and N-acetylglucosamine. Of the three commonly available forms of glucosamine, only glucosamine sulfate is given a "likely effective" rating for treating osteoarthritis. Glucosamine is often sold in combination with other supplements such as chondroitin sulfate and methylsulfonylmethane. Glucosamine, along with commonly used chondroitin, is not routinely prescribed to treat people who have symptomatic osteoarthritis of the knee, as there is insufficient evidence that this treatment is helpful. One clinical study over three years showed that glucosamine in doses of 1500 mg per day is safe to use. Glucosamine with or without chondroitin elevates the international normalized ratio (INR) in individuals who are taking the blood thinner, warfarin. It may also interfere with the efficacy of chemotherapy for treating cancer symptoms. Adverse effects may include stomach upset, constipation, diarrhea, headache, and rash. There are case reports of people who have chronic liver disease and a worsening of their condition with glucosamine supplementation. Glucosamine is naturally present in the shells of shellfish, animal bones, bone marrow, and fungi. D-Glucosamine is made naturally in the form of glucosamine-6-phosphate, and is the biochemical precursor of all nitrogen-containing sugars. Specifically in humans, glucosamine-6-phosphate is synthesized from fructose 6-phosphate and glutamine by glutamine—fructose-6-phosphate transaminase as the first step of the hexosamine biosynthesis pathway. The end-product of this pathway is uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), which is then used for making glycosaminoglycans, proteoglycans, and glycolipids. As the formation of glucosamine-6-phosphate is the first step for the synthesis of these products, glucosamine may be important in regulating their production; however, the way that the hexosamine biosynthesis pathway is actually regulated, and whether this could be involved in contributing to human disease remains unclear.

Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of the polysaccharides chitosan and chitin, which compose the exoskeletons of crustaceans and other arthropods, as well as the cell walls of fungi and many higher organisms. Glucosamine is one of the most abundant monosaccharides. It is produced commercially by the hydrolysis of crustacean exoskeletons or, less commonly, by fermentation of a grain such as corn or wheat. Oral glucosamine is a dietary supplement and is not a pharmaceutical drug. It is illegal in the US to market any dietary supplement as a treatment for any disease or condition. Glucosamine is marketed to support the structure and function of joints, and the marketing is targeted to people suffering from osteoarthritis. Commonly sold forms of glucosamine are glucosamine sulfate, glucosamine hydrochloride, and N-acetylglucosamine. Of the three commonly available forms of glucosamine, only glucosamine sulfate is given a "likely effective" rating for treating osteoarthritis. Glucosamine is often sold in combination with other supplements such as chondroitin sulfate and methylsulfonylmethane. Glucosamine, along with commonly used chondroitin, is not routinely prescribed to treat people who have symptomatic osteoarthritis of the knee, as there is insufficient evidence that this treatment is helpful. One clinical study over three years showed that glucosamine in doses of 1500 mg per day is safe to use. Glucosamine with or without chondroitin elevates the international normalized ratio (INR) in individuals who are taking the blood thinner, warfarin. It may also interfere with the efficacy of chemotherapy for treating cancer symptoms. Adverse effects may include stomach upset, constipation, diarrhea, headache, and rash. There are case reports of people who have chronic liver disease and a worsening of their condition with glucosamine supplementation. Glucosamine is naturally present in the shells of shellfish, animal bones, bone marrow, and fungi. D-Glucosamine is made naturally in the form of glucosamine-6-phosphate, and is the biochemical precursor of all nitrogen-containing sugars. Specifically in humans, glucosamine-6-phosphate is synthesized from fructose 6-phosphate and glutamine by glutamine—fructose-6-phosphate transaminase as the first step of the hexosamine biosynthesis pathway. The end-product of this pathway is uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), which is then used for making glycosaminoglycans, proteoglycans, and glycolipids. As the formation of glucosamine-6-phosphate is the first step for the synthesis of these products, glucosamine may be important in regulating their production; however, the way that the hexosamine biosynthesis pathway is actually regulated, and whether this could be involved in contributing to human disease remains unclear.

Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of the polysaccharides chitosan and chitin, which compose the exoskeletons of crustaceans and other arthropods, as well as the cell walls of fungi and many higher organisms. Glucosamine is one of the most abundant monosaccharides. It is produced commercially by the hydrolysis of crustacean exoskeletons or, less commonly, by fermentation of a grain such as corn or wheat. Oral glucosamine is a dietary supplement and is not a pharmaceutical drug. It is illegal in the US to market any dietary supplement as a treatment for any disease or condition. Glucosamine is marketed to support the structure and function of joints, and the marketing is targeted to people suffering from osteoarthritis. Commonly sold forms of glucosamine are glucosamine sulfate, glucosamine hydrochloride, and N-acetylglucosamine. Of the three commonly available forms of glucosamine, only glucosamine sulfate is given a "likely effective" rating for treating osteoarthritis. Glucosamine is often sold in combination with other supplements such as chondroitin sulfate and methylsulfonylmethane. Glucosamine, along with commonly used chondroitin, is not routinely prescribed to treat people who have symptomatic osteoarthritis of the knee, as there is insufficient evidence that this treatment is helpful. One clinical study over three years showed that glucosamine in doses of 1500 mg per day is safe to use. Glucosamine with or without chondroitin elevates the international normalized ratio (INR) in individuals who are taking the blood thinner, warfarin. It may also interfere with the efficacy of chemotherapy for treating cancer symptoms. Adverse effects may include stomach upset, constipation, diarrhea, headache, and rash. There are case reports of people who have chronic liver disease and a worsening of their condition with glucosamine supplementation. Glucosamine is naturally present in the shells of shellfish, animal bones, bone marrow, and fungi. D-Glucosamine is made naturally in the form of glucosamine-6-phosphate, and is the biochemical precursor of all nitrogen-containing sugars. Specifically in humans, glucosamine-6-phosphate is synthesized from fructose 6-phosphate and glutamine by glutamine—fructose-6-phosphate transaminase as the first step of the hexosamine biosynthesis pathway. The end-product of this pathway is uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), which is then used for making glycosaminoglycans, proteoglycans, and glycolipids. As the formation of glucosamine-6-phosphate is the first step for the synthesis of these products, glucosamine may be important in regulating their production; however, the way that the hexosamine biosynthesis pathway is actually regulated, and whether this could be involved in contributing to human disease remains unclear.

Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of the polysaccharides chitosan and chitin, which compose the exoskeletons of crustaceans and other arthropods, as well as the cell walls of fungi and many higher organisms. Glucosamine is one of the most abundant monosaccharides. It is produced commercially by the hydrolysis of crustacean exoskeletons or, less commonly, by fermentation of a grain such as corn or wheat. Oral glucosamine is a dietary supplement and is not a pharmaceutical drug. It is illegal in the US to market any dietary supplement as a treatment for any disease or condition. Glucosamine is marketed to support the structure and function of joints, and the marketing is targeted to people suffering from osteoarthritis. Commonly sold forms of glucosamine are glucosamine sulfate, glucosamine hydrochloride, and N-acetylglucosamine. Of the three commonly available forms of glucosamine, only glucosamine sulfate is given a "likely effective" rating for treating osteoarthritis. Glucosamine is often sold in combination with other supplements such as chondroitin sulfate and methylsulfonylmethane. Glucosamine, along with commonly used chondroitin, is not routinely prescribed to treat people who have symptomatic osteoarthritis of the knee, as there is insufficient evidence that this treatment is helpful. One clinical study over three years showed that glucosamine in doses of 1500 mg per day is safe to use. Glucosamine with or without chondroitin elevates the international normalized ratio (INR) in individuals who are taking the blood thinner, warfarin. It may also interfere with the efficacy of chemotherapy for treating cancer symptoms. Adverse effects may include stomach upset, constipation, diarrhea, headache, and rash. There are case reports of people who have chronic liver disease and a worsening of their condition with glucosamine supplementation. Glucosamine is naturally present in the shells of shellfish, animal bones, bone marrow, and fungi. D-Glucosamine is made naturally in the form of glucosamine-6-phosphate, and is the biochemical precursor of all nitrogen-containing sugars. Specifically in humans, glucosamine-6-phosphate is synthesized from fructose 6-phosphate and glutamine by glutamine—fructose-6-phosphate transaminase as the first step of the hexosamine biosynthesis pathway. The end-product of this pathway is uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), which is then used for making glycosaminoglycans, proteoglycans, and glycolipids. As the formation of glucosamine-6-phosphate is the first step for the synthesis of these products, glucosamine may be important in regulating their production; however, the way that the hexosamine biosynthesis pathway is actually regulated, and whether this could be involved in contributing to human disease remains unclear.

Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of the polysaccharides chitosan and chitin, which compose the exoskeletons of crustaceans and other arthropods, as well as the cell walls of fungi and many higher organisms. Glucosamine is one of the most abundant monosaccharides. It is produced commercially by the hydrolysis of crustacean exoskeletons or, less commonly, by fermentation of a grain such as corn or wheat. Oral glucosamine is a dietary supplement and is not a pharmaceutical drug. It is illegal in the US to market any dietary supplement as a treatment for any disease or condition. Glucosamine is marketed to support the structure and function of joints, and the marketing is targeted to people suffering from osteoarthritis. Commonly sold forms of glucosamine are glucosamine sulfate, glucosamine hydrochloride, and N-acetylglucosamine. Of the three commonly available forms of glucosamine, only glucosamine sulfate is given a "likely effective" rating for treating osteoarthritis. Glucosamine is often sold in combination with other supplements such as chondroitin sulfate and methylsulfonylmethane. Glucosamine, along with commonly used chondroitin, is not routinely prescribed to treat people who have symptomatic osteoarthritis of the knee, as there is insufficient evidence that this treatment is helpful. One clinical study over three years showed that glucosamine in doses of 1500 mg per day is safe to use. Glucosamine with or without chondroitin elevates the international normalized ratio (INR) in individuals who are taking the blood thinner, warfarin. It may also interfere with the efficacy of chemotherapy for treating cancer symptoms. Adverse effects may include stomach upset, constipation, diarrhea, headache, and rash. There are case reports of people who have chronic liver disease and a worsening of their condition with glucosamine supplementation. Glucosamine is naturally present in the shells of shellfish, animal bones, bone marrow, and fungi. D-Glucosamine is made naturally in the form of glucosamine-6-phosphate, and is the biochemical precursor of all nitrogen-containing sugars. Specifically in humans, glucosamine-6-phosphate is synthesized from fructose 6-phosphate and glutamine by glutamine—fructose-6-phosphate transaminase as the first step of the hexosamine biosynthesis pathway. The end-product of this pathway is uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), which is then used for making glycosaminoglycans, proteoglycans, and glycolipids. As the formation of glucosamine-6-phosphate is the first step for the synthesis of these products, glucosamine may be important in regulating their production; however, the way that the hexosamine biosynthesis pathway is actually regulated, and whether this could be involved in contributing to human disease remains unclear.