Glucosamine sulfate is a naturally occurring chemical found in the human body. It is in the fluid that is around joints. Glucosamine is also found in other places in nature. For example, the glucosamine sulfate that is put into dietary supplements is often harvested from the shells of shellfish. Glucosamine sulfate used in dietary supplements does not always come from natural sources. It can also be made in a laboratory.
There are different forms of glucosamine including glucosamine sulfate, glucosamine hydrochloride, and N-acetyl-glucosamine. These different chemicals have some similarities; however, they may not have the same effects when taken as a dietary supplement. Most of the scientific research done on glucosamine has been done on glucosamine sulfate. The information on this page pertains to glucosamine sulfate. For information on the other forms of glucosamine, see the specific pages for each of them.
Dietary supplements that contain glucosamine often contain additional ingredients. These additional ingredients are frequently chondroitin sulfate, MSM, or shark cartilage. Some people think these combinations work better than taking just glucosamine sulfate alone. So far, researchers have found no proof that combining the additional ingredients with glucosamine adds any benefit.
Some glucosamine sulfate products are not labeled accurately. 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.
Glucosamine sulfate is taken by mouth for osteoarthritis, glaucoma, weight loss, joint pain caused by drugs, a bladder condition called interstitial cystitis, jaw pain, joint pain including knee pain, back pain, multiple sclerosis, and HIV/AIDS.
Glucosamine is also in some skin creams used to control arthritis pain. These creams usually contain camphor and other ingredients in addition to glucosamine.
Glucosamine sulfate is used parenterally for osteoarthritis.
How it works
Glucosamine sulfate is a chemical found in the human body. It is used by the body to produce a variety of other chemicals that are involved in building tendons, ligaments, cartilage, and the thick fluid that surrounds joints.
Joints are cushioned by the fluid and cartilage that surround them. In some people with osteoarthritis, the cartilage breaks down and becomes thin. This results in more joint friction, pain, and stiffness. Researchers think that taking glucosamine supplements may either increase the cartilage and fluid surrounding joints or help prevent breakdown of these substances, or maybe both.
Some researchers think the "sulfate" part of glucosamine sulfate is also important. Sulfate is needed by the body to produce cartilage. This is one reason why researchers believe that glucosamine sulfate might work better than other forms of glucosamine such as glucosamine hydrochloride or N-acetyl glucosamine. These other forms do not contain sulfate.
Most research shows that taking glucosamine sulfate can provide some pain relief for people with osteoarthritis, especially those with osteoarthritis of the knees. For some people, glucosamine sulfate might work as well as over-the-counter and prescription pain medications such as acetaminophen or ibuprofen; however, pain medications work quickly while glucosamine sulfate can take 4-8 weeks before it provides pain relief. Also people who take glucosamine sulfate often still need to take pain medications for pain flare-ups. In addition to relieving pain, glucosamine sulfate might also slow the breakdown of joints and prevent the condition from getting worse if it is taken for several years. Some research shows that people who take glucosamine sulfate might be less likely to need total knee replacement surgery.There are several kinds of glucosamine products. The most research showing benefit is for products that contain glucosamine sulfate. Products that contain glucosamine hydrochloride do not seem to work as well. Many products contain both glucosamine with chondroitin, but there is no evidence that these products work any better than glucosamine sulfate by itself.
Glucosamine sulfate is LIKELY SAFE when used appropriately by mouth in adults
Glucosamine sulfate is POSSIBLY SAFE when injected into the muscle as a shot twice weekly for up to 6 weeks or when applied to the skin in combination with chondroitin sulfate, shark cartilage, and camphor for up to 8 weeks. Glucosamine sulfate can cause some mild side effects including nausea, heartburn, diarrhea, and constipation. Uncommon side effects are drowsiness, skin reactions, and headache. These are rare.
Pregnancy or breast-feeding: There is not enough reliable scientific information available to know if glucosamine sulfate is safe to take duringpregnancyor whilebreast-feeding. Until more is known, do not take glucosamine sulfate whilepregnantor breast-feeding.
Asthma: There is one report linking an asthma attack with taking glucosamine. It is not known for sure if glucosamine was the cause of the asthma attack. Until more is known, people with asthma should be cautious about taking products that contain glucosamine.
Diabetes: Some early research suggested that glucosamine sulfate might raise blood sugar in people with diabetes. However, more recent and more reliable research now shows that glucosamine sulfate does not seem to affect blood sugar control in people with type 2 diabetes. Glucosamine appears to be safe for most people with diabetes, but blood sugar should be monitored closely.
High cholesterol: Animal research suggests that glucosamine may increase cholesterol levels. In contrast, glucosamine does not seem to increase cholesterol levels in humans. However, some early research suggests that glucosamine might increase insulin levels. This might cause cholesterol levels to increase. To be cautious, if you take glucosamine sulfate and have high cholesterol. Monitor your cholesterol levels closely.
High blood pressure: Early research suggests that glucosamine sulfate can increase insulin levels. This might cause blood pressure to increase. However, more reliable research suggests that glucosamine sulfate does not increase blood pressure. To be cautious, if you take glucosamine sulfate and have high blood pressure, monitor your blood pressure closely.
Shellfish allergy: Because some glucosamine sulfate products are made from the shells of shrimp, lobsters or crabs, there is concern that glucosamine products might cause allergic reactions in people who are allergic to shellfish. However, allergic reactions in people with shellfish allergy are typically caused by the meat of shellfish, not the shell. There are no reports of allergic reactions to glucosamine in people who are allergic to shellfish. There is also some information that people with shellfish allergy can safely take glucosamine products.
Surgery: Glucosamine sulfate might affect blood sugar levels and might interfere with blood sugar control during and after surgery. Stop taking glucosamine sulfate at least 2 weeks before a scheduled surgery.
Warfarin (Coumadin) is used to slow blood clotting. There are several reports showing that taking glucosamine sulfate with or without chondroitin increases the effect of warfarin (Coumadin), making blood clotting even slower. This can cause bruising and bleeding that can be serious. Don't take glucosamine sulfate if you are taking warfarin (Coumadin). Many natural medicines can interact with warfarin (Coumadin).
MinorAcetaminophen (Tylenol, others)
Some medications for cancer work by decreasing how fast cancer cells can copy themselves. Some scientists think that glucosamine sulfate might increase how fast tumor cells can copy themselves. Taking glucosamine sulfate along with some medications for cancer might decrease the effectiveness of these medications for cancer. Any person who is receiving chemotherapy should talk with their health provider before taking glucosamine sulfate.Some of these medications are etoposide (VP16, VePesid), teniposide (VM26), and doxorubicin (Adriamycin).There is some concern that taking glucosamine sulfate and acetaminophen (Tylenol, others) together might affect how well each works. However, more information is needed to know if this interaction is a big concern. For now, most experts say it is okay to use both together.Medications for diabetes (Antidiabetes drugs)
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 diabetes medications work. However, research now shows 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.