N-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.
Natural Medicines rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.
- 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.
More evidence is needed to rate the effectiveness of N-acetyl glucosamine for these uses.
N-acetyl glucosamine might help protect the lining of the stomach and intestines.
When 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.
Acetaminophen (Tylenol, others)
Interaction Rating=Minor Be watchful with this combination.
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.
Medications for cancer (Chemotherapy)
Interaction Rating=Moderate Be cautious with this combination.
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)
Interaction Rating=Moderate Be cautious with this combination.
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.
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.
Interaction Rating=Major Do not take this combination.
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).
There are no known interactions with herbs and supplements.
There are no known interactions with foods.
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.
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.
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