Glucosamine is used by the body to make other chemicals that build tendons, ligaments, cartilage, and the fluid that surrounds joints. Joints are cushioned by the fluid and cartilage around them. Taking glucosamine might increase the cartilage and fluid around joints and/or help prevent their breakdown.
People commonly use glucosamine sulfate and glucosamine hydrochloride for osteoarthritis. Glucosamine is also used for joint pain, rheumatoid arthritis, multiple sclerosis, and many other conditions, but there is no good scientific evidence to support these other uses.
How does it work ?
Uses & Effectiveness
Likely Effective for
- Osteoarthritis. Taking glucosamine sulfate by mouth for at least 4 weeks can provide some pain relief and improve function for people with knee osteoarthritis. Products that contain glucosamine hydrochloride do not seem to work as well unless they are taken in combination with other ingredients. Taking glucosamine sulfate doesn't seem to reduce the risk of getting osteoarthritis.
Insufficient Evidence for
- Joint pain caused by drugs called aromatase inhibitors (aromatase inhibitor-induced arthralgias). Early research suggests that taking a combination of glucosamine sulfate and chondroitin sulfate in two or three divided doses daily for 24 weeks reduces pain in women taking drugs that lower estrogen levels for early stage breast cancer.
- 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. It's also unclear if this lower risk is from glucosamine or from following healthier lifestyle habits.
- Depression. Early research shows that taking glucosamine hydrochloride for 4 weeks might improve symptoms of depression in some people with depression.
- Diabetes. People who take glucosamine might have a lower risk of developing diabetes. But it's unclear what dose or form of glucosamine might work best. It's also unclear if this lower risk is from glucosamine or from following healthier lifestyle habits.
- High levels of cholesterol or other fats (lipids) in the blood (hyperlipidemia). Early research suggests that glucosamine hydrochloride does not affect cholesterol or triglyceride levels in people with high cholesterol.
- 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 disease or ulcerative colitis.
- A disorder that affects the bones and joints, usually in people with selenium deficiency (Kashin-Beck disease). Early evidence shows that taking glucosamine hydrochloride along with chondroitin sulfate reduces pain and improves physical function in adults with this condition. Taking glucosamine hydrochloride alone might work as well as over-the-counter pain medications.
- Knee pain. Early research shows that taking 1500 mg of glucosamine sulfate daily for 28 days does not reduce knee pain in athletes following a knee injury. But it does seem to improve knee movement. There is some early evidence that glucosamine hydrochloride might relieve pain for some people with frequent knee pain.
- Multiple sclerosis (MS). Early research shows that taking glucosamine sulfate by mouth daily for 6 months might reduce the relapse of multiple sclerosis.
- Recovery after surgery. Early research shows that taking glucosamine sulfate does not improve function, pain, and performance in male athletes who had surgery to fix a torn ACL. The ACL is a ligament that holds the knee in place during movement.
- Rheumatoid arthritis (RA). Early research shows that taking glucosamine hydrochloride might reduce pain but not the number of swollen and painful joints.
- Stroke. Early research has found that 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. But it is unclear if this lower risk is from glucosamine or from healthier lifestyle habits.
- A group of painful conditions that affect the jaw joint and muscle (temporomandibular disorders or TMD). Early research disagrees on whether glucosamine sulfate reduces pain in people with osteoarthritis of the jaw joint.
- Aging skin.
- Back pain.
- Non-cancerous growths in the large intestine and rectum (colorectal adenoma).
- Death from any cause.
- Joint pain.
- Painful bladder syndrome (Interstitial cystitis).
- Wound healing.
- Other conditions.
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 and Warnings
Asthma: Glucosamine might make asthma worse. Until more is known, people with asthma should be cautious about taking products that contain glucosamine.
Diabetes: There used to be some concern that glucosamine might increase blood sugar levels. But most research shows that glucosamine doesn't increase blood sugar levels in people with diabetes.
Glaucoma: Glucosamine might increase the pressure inside the eye and could worsen glaucoma. If you have glaucoma, talk to your healthcare provider before taking glucosamine.
High cholesterol: There used to be some concern that glucosamine might increase cholesterol levels. But most research shows that glucosamine doesn't seem to increase cholesterol levels.
High blood pressure: There used to be some concern that glucosamine might increase blood pressure. But most research shows that glucosamine does not seem to increase blood pressure.
Shellfish allergy: Glucosamine is produced from the shells of shrimp, lobster, and crabs. If you have a shellfish allergy, talk to your healthcare provider before using glucosamine.
Warfarin (Coumadin) interacts with GLUCOSAMINE
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).
Do not take this combination
Medications for cancer (Antimitotic chemotherapy) interacts with GLUCOSAMINE
Some medications for cancer work by decreasing how fast cancer cells can copy themselves. Some scientists think that glucosamine might increase how fast tumor cells can copy themselves. Taking glucosamine along with some medications for cancer might decrease the effectiveness of these medications for cancer.
Some of these medications are etoposide (VP16, VePesid), teniposide (VM26), and doxorubicin (Adriamycin).
Be cautious with this combination
Acetaminophen (Tylenol, others) interacts with GLUCOSAMINE
There is some concern that taking glucosamine sulfate 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 diabetes (Antidiabetes drugs) interacts with GLUCOSAMINE
There has been concern that glucosamine sulfate might increase blood sugar in people with diabetes. There was also the concern that glucosamine sulfate might decrease how well medications used for diabetes work. However, research now indicates that glucosamine sulfate probably does not increase blood sugar in people with diabetes. Therefore, glucosamine sulfate probably does not interfere with diabetes medications. To be cautious, if you take glucosamine sulfate 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.
Be watchful with this combination
Keep in mind that glucosamine used in supplements often comes from the shells of shellfish. Talk to your healthcare provider before taking these supplements if you have a shellfish allergy. Also, some glucosamine products aren't labeled correctly. In some cases, the amount of glucosamine actually in the product has varied from none to over 100% of the amount stated on the product's label. Some products have contained glucosamine hydrochloride when glucosamine sulfate was listed on the label.
CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.
This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version. © Therapeutic Research Faculty 2018.