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.
Natural Medicines Comprehensive Database 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.
The effectiveness ratings for GLUCOSAMINE SULFATE are as follows:
Likely effective for…
- Osteoarthritis. 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.
Insufficient evidence to rate effectiveness for…
- Joint pain caused by drugs that lower estrogen levels. 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.
- Painful bladder syndrome (Interstitial cystitis). Early research suggests that taking a specific product containing glucosamine sulfate, sodium hyaluronate, chondroitin sulfate, quercetin, and rutin (CystoProtek, Tischon Corporation, Westbury, NY) four times daily for 12 months reduces symptoms of painful bladder syndrome.
- Joint pain. Research shows that taking a specific product containing glucosamine sulfate, methylsufonlylmethane, white willow bark extract, ginger root concentrate, Indian frankincense extract, turmeric root extract, cayenne, and hyaluronic acid (Instaflex Joint Support, Direct Digital, Charlotte, NC) in three divided doses daily for 8 weeks reduces joint pain. But this product doesn’t seem to help joint stiffness or function.
- Knee pain. Some research shows that taking a specific product containing glucosamine sulfate, methylsufonlylmethane, white willow bark extract, ginger root concentrate, Indian frankincense extract, turmeric root extract, cayenne, and hyaluronic acid (Instaflex Joint Support, Direct Digital, Charlotte, NC) in three divided doses daily for 8 weeks reduces joint pain in people with knee pain. But this product doesn’t seem to help joint stiffness or function. Other 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. However, it does seem to improve knee movement.
- Multiple sclerosis. Early research shows that taking 1000 mg of glucosamine sulfate by mouth daily for 6 months might reduce the relapse of multiple sclerosis.
- Jaw pain (Temporomandibular disorder). Some research shows that taking glucosamine sulfate works about as well as the nonsteroidal anti-inflammatory drug (NSAID) ibuprofen (Motrin, Advil, etc.) for relieving jaw pain. In some people, pain relief appears to continue for up to 90 days after glucosamine sulfate is discontinued. However, research suggests that when 1200 mg of glucosamine sulfate is taken by mouth daily for 6 months, jaw pain and the ability to open the jaw are not improved.
- Weight loss.
- Other conditions.
More evidence is needed to rate glucosamine sulfate for these uses.
- For osteoarthritis: 1500 mg once daily or 500 mg three times daily, either alone or together with 400 mg of chondroitin sulfate two or three times daily, has been used for up to 3 years. Also glucosamine sulfate 750 mg twice daily in combination with turmeric root extract 500 mg twice daily has been used for 6 weeks.
APPLIED TO THE SKIN:
- For osteoarthritis: A cream containing 30 mg/gram of glucosamine sulfate, 50 mg/gram of chondroitin sulfate, 140 mg/gram of chondroitin sulfate, 32 mg/gram of camphor, and 9 mg/gram of peppermint oil has been applied to the skin as needed for 8 weeks.
INJECTED INTO THE MUSCLE:
- For osteoarthritis: 400 mg of glucosamine sulfate has been injected twice weekly for 6 weeks.
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.
Special precautions & warnings:
Pregnancy or breast-feeding: There is not enough reliable scientific information available to know if glucosamine sulfate is safe to take during pregnancy or while breast-feeding. Until more is known, do not take glucosamine sulfate while pregnant or 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.
Glaucoma: Glucosamine sulfate 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: 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 on the safe side, monitor your cholesterol levels closely if you take glucosamine sulfate and have high cholesterol.
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 on the safe side, monitor your blood pressure closely if you take glucosamine sulfate and have high blood pressure.
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.
Interaction with medication
- Warfarin (Coumadin)
- 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).
- Medications for cancer (Antimitotic chemotherapy)
- 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).
- Acetaminophen (Tylenol, others)
- 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.