N-ACETYL GLUCOSAMINE (NAG)
2-Acetamido-2-deoxyglucose, Acetylglucosamine, Acétylglucosamine, GlcNAc, Glucosamine, Glucosamine-6-phosphate, Glucosamine N-Acetyl, N-Acetil Glucosamina, N-Acétyl Glucosamine, N-Acétyl-Glucosamine, N-Acétylglucosamine, N-Acetyl D-Glucosamine, N-Acétyl D-Glucosamine, NAG, N-A-G, pGlcNAc, Poly-N-Acetyl Glucosamine, Poly-NAG, p-GlcNAc.<br/><br/>
Overview InformationN-acetyl glucosamine is a chemical that comes from the outer shells of shellfish. It can also be made in labs.
Don't confuse N-acetyl glucosamine with other forms of glucosamine, such as glucosamine hydrochloride or glucosamine sulfate. They may not have the same effects.
Read glucosamine product labels carefully for their content. Most glucosamine products contain glucosamine sulfate or glucosamine hydrochloride. Although glucosamine sulfate and glucosamine hydrochloride are marketed together in combination products with N-acetyl glucosamine, there haven't been any human studies that have evaluated these combinations for treating osteoarthritis.
You may also see chitosan as an ingredient in some glucosamine products. Chitosan is a form of N-acetyl glucosamine that has been chemically altered.
N-acetyl glucosamine is used for osteoarthritis, aging skin, knee pain, and inflammatory bowel disease (IBD), but there is no good scientific evidence to support these uses.
How does it work?N-acetyl glucosamine might help protect the lining of the stomach and intestines.
Uses & Effectiveness
Insufficient Evidence for
- Aging skin. Early research shows that applying a cream containing 2% N-acetyl glucosamine and 4% niacinamide to the face decreases dark spots caused by aging and sun exposure. It's unclear if applying a cream containing only N-acetyl glucosamine would have the same effect.
- Heart disease. People who take glucosamine might have a lower risk of developing heart disease. But it's unclear what dose or form of glucosamine might work best. Other forms of glucosamine include glucosamine hydrochloride and glucosamine sulfate. It's also unclear if this lower risk is from glucosamine or from following healthier lifestyle habits.
- Long-term swelling (inflammation) in the digestive tract (inflammatory bowel disease or IBD). There is some early evidence that N-acetyl glucosamine taken by mouth or rectally might decrease symptoms of IBD in children with Crohn's disease or ulcerative colitis.
- Knee pain. Early research shows that taking N-acetyl glucosamine along with chondroitin sulfate does not relieve pain in middle-aged and older adults with long-term knee pain.
- Stroke. People who take glucosamine might have a slightly lower risk of having a stroke. But it's unclear what dose or form of glucosamine might work best. Other forms of glucosamine include glucosamine hydrochloride and glucosamine sulfate. It's also unclear if this lower risk is from glucosamine or from following healthier lifestyle habits.
- Other conditions.
Side Effects & SafetyWhen taken by mouth: N-acetyl glucosamine is POSSIBLY SAFE when taken in doses of 3-6 grams daily.
When applied to the skin: N-acetyl glucosamine is POSSIBLY SAFE when used for up to 10 weeks.
When given as an enema (rectally): N-acetyl glucosamine is POSSIBLY SAFE when used in doses of 3-4 grams daily.
Special Precautions & Warnings:Pregnancy and breast-feeding: There isn't enough reliable information to know if N-acetyl glucosamine is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid use.
Asthma: Researchers aren't sure why, but glucosamine might make asthma worse in some people. If you have asthma, use caution when trying N-acetyl glucosamine.
Diabetes: Some early research suggested that glucosamine might raise blood sugar in people with diabetes. However, more reliable research indicates that glucosamine does not seem to significantly affect blood sugar control in people with type 2 diabetes. As long as you routinely monitor your blood sugar, you can probably take glucosamine, including N-acetyl glucosamine, safely.
Shellfish allergy: There is some concern that glucosamine products might cause allergic reactions in people who are sensitive to shellfish. Glucosamine is produced from the shells of shrimp, lobster, and crabs. Allergic reactions in people with shellfish allergy are caused by the meat of shellfish, not the shell. But some people have developed an allergic reaction after using glucosamine supplements. It is possible that some glucosamine products might be contaminated with the part of the shellfish meat that can cause an allergic reaction. If you have a shellfish allergy, talk to your provider before using glucosamine.
Surgery: N-acetyl glucosamine might affect blood sugar levels and might interfere with blood sugar control during and after surgery. Stop taking N-acetyl glucosamine at least 2 weeks before a scheduled surgery.
Do not take this combination
Warfarin (Coumadin) interacts with N-ACETYL GLUCOSAMINE (NAG)
Warfarin (Coumadin) is used to slow blood clotting. There are several reports showing that taking glucosamine with or without chondroitin increase the effect of warfarin (Coumadin) on blood clotting. This can cause bruising and bleeding that can be serious. Don't take glucosamine if you are taking warfarin (Coumadin).
Be cautious with this combination
Medications for cancer (Chemotherapy) interacts with N-ACETYL GLUCOSAMINE (NAG)
There is some concern that N-acetyl glucosamine might decrease the effectiveness of some medications for cancer. But it is too soon to know if this interaction occurs.
Medications for diabetes (Antidiabetes drugs) interacts with N-ACETYL GLUCOSAMINE (NAG)
There has been concern that glucosamine might increase blood sugar in people with diabetes. There was also the concern that glucosamine might decrease how well medications used for diabetes work. However, research now indicates that glucosamine probably does not increase blood sugar in people with diabetes. Therefore, glucosamine probably does not interfere with diabetes medications. To be cautious, if you take N-acetyl glucosamine and have diabetes, monitor your blood sugar closely.<br/><br/> Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.
Be watchful with this combination
Acetaminophen (Tylenol, others) interacts with N-ACETYL GLUCOSAMINE (NAG)
There is some concern that taking glucosamine and acetaminophen (Tylenol, others) together might affect how well each works. But more information is needed to know if this interaction is a big concern.
The appropriate dose of N-acetyl glucosamine depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for N-acetyl glucosamine. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.
- Adams ME. Hype about glucosamine. Lancet 1999;354:353-4. View abstract.
- Almada A, Harvey P, Platt K. Effects of chronic oral glucosamine sulfate on fasting insulin resistance index (FIRI) in non-diabetic individuals. FASEB J 2000;14:A750.
- Balkan B, Dunning BE. Glucosamine inhibits glucokinase in vitro and produces a glucose-specific impairment of in vivo insulin secretion in rats. Diabetes 1994;43:1173-9. View abstract.
- Barclay TS, Tsourounis C, McCart GM. Glucosamine. Ann Pharmacother 1998;32:574-9. View abstract.
- Burton AF, Anderson FH. Decreased incorporation of 14C-glucosamine relative to 3H-N-acetyl glucosamine in the intestinal mucosa of patients with inflammatory bowel disease. Am J Gastroenterol 1983;78:19-22. View abstract.
- Danao-Camara T. Potential side effects of treatment with glucosamine and chondroitin. Arthritis Rheum 2000;43:2853. View abstract.
- Does glucosamine increase serum lipid levels and blood pressure? Pharmacist's Letter/Prescriber's Letter 2001;17(11):171115.
- Du XL, Edelstein D, Dimmeler S, et al. Hyperglycemia inhibits endothelial nitric oxide synthase activity by post-translational modification at the Akt site. J Clin Invest 2001;108:1341-8. View abstract.
- Giaccari A, Morviducci L, Zorretta D, et al. In vivo effects of glucosamine on insulin secretion and insulin sensitivity in the rat: possible relevance to the maladaptive responses to chronic hyperglycaemia. Diabetologia 1995;38:518-24. View abstract.
- Guillaume MP, Peretz A. Possible association between glucosamine treatment and renal toxicity: comment on the letter by Danao-Camara. Arthritis Rheum 2001;44:2943-4. View abstract.
- Hoban C, Byard R, Musgrave I. Hypersensitive adverse drug reactions to glucosamine and chondroitin preparations in Australia between 2000 and 2011. Postgrad Med J. 2019 Oct 9. pii: postgradmedj-2019-136957. View abstract.
- Hochberg MC, Martel-Pelletier J, Monfort J, Möller I, Castillo JR, Arden N,Berenbaum F, Blanco FJ, Conaghan PG, Doménech G, Henrotin Y, Pap T, Richette P, Sawitzke A, du Souich P, Pelletier JP; on behalf of the MOVES Investigation Group. Combined chondroitin sulfate and glucosamine for painful knee osteoarthritis: a multicentre, randomised, double-blind, non-inferiority trial versus celecoxib. Ann Rheum Dis 2016;75(1):37-44. View abstract.
- Holmang A, Nilsson C, Niklasson M, et al. Induction of insulin resistance by glucosamine reduces blood flow but not interstitial levels of either glucose or insulin. Diabetes 1999;48:106-11. View abstract.
- Kim YB, Zhu JS, Zierath JR, et al. Glucosamine infusion in rats rapidly impairs insulin stimulation of phosphoinositide 3-kinase but does not alter activation of Akt/protein kinase B in skeletal muscle. Diabetes 1999;48:310-20. View abstract.
- Kimball AB, Kaczvinsky JR, Li J, et al. Reduction in the appearance of facial hyperpigmentation after use of moisturizers with a combination of topical niacinamide and N-acetyl glucosamine: results of a randomized, double-blind, vehicle-controlled trial. Br J Dermatol 2010;162(2):435-41. View abstract.
- Knudsen J, Sokol GH. Potential glucosamine-warfarin interaction resulting in increased international normalized ratio: Case report and review of the literature and MedWatch database. Pharmacotherapy 2008;28:540-8. View abstract.
- Ma H, Li X, Sun D, et al. Association of habitual glucosamine use with risk of cardiovascular disease: prospective study in UK Biobank. BMJ. 2019 May 14;365:l1628. View abstract.
- McAlindon T. Why are clinical trials of glucosamine no longer uniformly positive? Rheum Dis Clin North Am 2003;29:789-801. View abstract.
- Monauni T, Zenti MG, Cretti A, et al. Effects of glucosamine infusion on insulin secretion and insulin action in humans. Diabetes 2000;49:926-35. View abstract.
- Muniyappa R, Karne RJ, Hall G, et al. Oral glucosamine for 6 weeks at standard doses does not cause or worsen insulin resistance or endothelial dysfunction in lean or obese subjects. Diabetes 2006;55:3142-50. View abstract.
- Nowak A, Szczesniak L, Rychlewski T, et al. Glucosamine levels in people with ischaemic heart disease with and without type II diabetes. Pol Arch Med Wewn 1998;100:419-25. View abstract.
- Olszewski AJ, Szostak WB, McCully KS. Plasma glucosamine and galactosamine in ischemic heart disease. Atherosclerosis 1990;82:75-83. View abstract.
- Pavelka K, Gatterova J, Olejarova M, et al. Glucosamine sulfate use and delay of progression of knee osteoarthritis: A 3-year, randomized, placebo-controlled, double-blind study. Arch Intern Med 2002;162:2113-23. View abstract.
- Pham T, Cornea A, Blick KE, et al. Oral glucosamine in doses used to treat osteoarthritis worsens insulin resistance. Am J Med Sci 2007;333:333-9. View abstract.
- Pouwels MJ, Jacobs JR, Span PN, et al. Short-term glucosamine infusion does not affect insulin sensitivity in humans. J Clin Endocrinol Metab 2001;86:2099-103. View abstract.
- Qiu GX, Gao SN, Giacovelli G, et al. Efficacy and safety of glucosamine sulfate versus ibuprofen in patients with knee osteoarthritis. Arzneimittelforschung 1998;48:469-74. View abstract.
- Reginster JY, Deroisy R, Rovati LC, et al. Long-term effects of glucosamine sulfate on osteoarthritis progression: a randomised, placebo-controlled trial. Lancet 2001;357:251-6. View abstract.
- Rossetti L, Hawkins M, Chen W, et al. In vivo glucosamine infusion induces insulin resistance in normoglycemic but not in hyperglycemic conscious rats. J Clin Invest 1995;96:132-40. View abstract.
- Rozenfeld V, Crain JL, Callahan AK. Possible augmentation of warfarin effect by glucosamine-chondroitin. Am J Health Syst Pharm 2004;61:306-307. View abstract.
- Salvatore S, Heuschkel R, Tomlin S, et al. A pilot study of N-acetyl glucosamine, a nutritional substrate for glycosaminoglycan synthesis, in paediatric chronic inflammatory bowel disease. Aliment Pharmacol Ther 2000;14:1567-79.. View abstract.
- Scroggie DA, Albright A, Harris MD. The effect of glucosamine-chondroitin supplementation on glycosylated hemoglobin levels in patients with type 2 diabetes mellitus: a placebo-controlled, double-blinded, randomized clinical trial. Arch Intern Med 2003;163:1587-90. View abstract.
- Setnikar I, Palumbo R, Canali S, et al. Pharmacokinetics of glucosamine in man. Arzneimittelforschung 1993;43:1109-13. View abstract.
- Shankar RR, Zhu JS, Baron AD. Glucosamine infusion in rats mimics the beta-cell dysfunction of non-insulin-dependent diabetes mellitus. Metabolism 1998;47:573-7. View abstract.
- Stumpf JL, Lin SW. Effect of glucosamine on glucose control. Ann Pharmacother 2006;40:694-8. View abstract.
- Tallia AF, Cardone DA. Asthma exacerbation associated with glucosamine-chondroitin supplement. J Am Board Fam Pract 2002;15:481-4.. View abstract.
- Tannis AJ, Barban J, Conquer JA. Effect of glucosamine supplementation on fasting and non-fasting plasma glucose and serum insulin concentrations in healthy individuals. Osteoarthritis Cartilage 2004;12:506-11. View abstract.
- Tannock LR, Kirk EA, King VL, et al. Glucosamine supplementation accelerates early but not late atherosclerosis in LDL receptor-deficient mice. J Nutr 2006;136:2856-61. View abstract.
- Tsuji T, Yoon J, Kitano N, Okura T, Tanaka K. Effects of N-acetyl glucosamine and chondroitin sulfate supplementation on knee pain and self-reported knee function in middle-aged and older Japanese adults: a randomized, double-blind, placebo-controlled trial. Aging Clin Exp Res. 2016;28(2):197-205. View abstract.
- Weimann G, Lubenow N, Selleng K, et al. Glucosamine sulfate does not crossreact with the antibodies of patients with heparin-induced thrombocytopenia. Eur J Haematol 2001;66:195-9. View abstract.
- Yu JG, Boies SM, Olefsky JM. The effect of oral glucosamine sulfate on insulin sensitivity in human subjects. Diabetes Care 2003;26:1941-2. View abstract.
- Yue QY, Strandell J, Myrberg O. Concomitant use of glucosamine may potential the effect of warfarin. The Uppsala Monitoring Centre. Available at: www.who-umc.org/graphics/9722.pdf (Accessed 28 April 2008).
- Yun J, Tomida A, Nagata K, Tsuruo T. Glucose-regulated stresses confer resistance to VP-16 in human cancer cells through a decreased expression of DNA topoisomerase II. Oncol Res 1995;7:583-90. View abstract.
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