Glucosamine and chondroitin sulfate are popular dietary supplements people suffering with osteoarthritis often take to alleviate pain, reduce swelling, ease stiffness, and improve joint function. The supplements (see https://harnessingstrength.com/best-glucosamine-supplements-reviews-powders-pills-tablets/ for more) can potentially help to control the onset of osteoarthritis by preventing the breakdown of cartilage. Many people rave about the help these supplements provide (Harnessing Strength also provides information about that). Experts at the National Institutes of Health say using glucosamine and chondroitin sulfate appears to be safe for use by most adults. However, they caution users may experience some side effects.
What Are The Side Effects Of Taking Glucosamine?
While the risk to pregnant and breastfeeding women is unknown, there are several glucosamine side effects of which people should be aware of before they begin taking the supplement. Some of the mild side effects people experience when taking glucosamine include:
- Gas
- Bloating
- Constipation
- Diarrhea
- Nausea
- Upset Stomach
- Heartburn
- Indigestion
Some of the more serious glucosamine sulfate side effects include:
- Drowsiness
- Headache
- Vomiting
- Skin Reactions
- Elevated Blood Pressure
- Palpitations
- Rapid Heart Rate
To reduce the digestive issues some people experience when taking glucosamine, it’s recommended they make sure to eat some food before taking the supplement.

Glucosamine And Shellfish Allergies
Glucosamine is a compound produced naturally in the body. It’s also found in the shells of lobsters, shrimp and other types of shellfish. The glucosamine used in many dietary supplements is either sourced from shellfish or synthetic forms of the compound. People with shellfish allergies should verify the glucosamine in the dietary supplement they plan to take is from a non-shellfish source or avoid the glucosamine supplement. Companies marketing glucosamine supplements are not required to put the source of its glucosamine on the label. You have to contact the manufacturer to confirm the source of the glucosamine in it.
What Is Chondroitin?
A naturally occurring compound in the body of humans and animals, chondroitin is a major component of cartilage as well as other connective tissue. A glycosaminoglycan, chondroitin is primarily found as sulfate esters. Chondroitin may help to reduce pain and increase joint mobility and is also a very popular osteoarthritis treatment. When used to prevent and treat osteoarthritis, chondroitin is delivered in much higher amounts than is produced naturally by the human body. The chondroitin sulfate in many dietary supplements is produced from cow cartilage and other animal sources. Its most common side effects are nausea and mild stomach pain.
Glucosamine And Chondroitin Side Effects
Some people take a supplement that combines glucosamine and chondroitin to alleviate pain, prevent and treat cartilage breakdown, reduce swelling, ease stiffness, improve joint function and control the other often painful and debilitating symptoms of osteoarthritis. The combination generally works well, but the side effects of glucosamine chondroitin are common. However, for many people, any glucosamine and chondroitin side effect is worth the risk because of the pain relief and help treating the temporomandibular joint disorder and other conditions they provide. Common glucosamine chondroitin side effects include:
- Constipation
- Diarrhea
- Hair Loss
- Heartburn
- Nausea
- Increased Intestinal Gas
- Irregular Heartbeat
- Swollen Eyelids Or Legs
The side effects associated with taking the combination of glucosamine and chondroitin are generally mild. Although not all the combination of glucosamine and chondroitin side effects are known, most doctors agree to take them together for as long as 2 years is generally considered to be safe. However, you should talk to your doctor before you begin using the supplements. If you develop difficulty breathing, hives, swelling of the face, tongue, lips, or throat or any other signs you are having an allergic reaction to the supplements, get emergency medical help immediately.
Potential Complications
Two potentially serious side effects of glucosamine chondroitin supplements are irregular heartbeats and swelling of the legs. People who experience these while using the supplements should stop taking them immediately and contact their doctor. Using the combination of supplements may aggravate and have harmful effects on people with chronic conditions like asthma, blood clotting disorders, diabetes, high blood pressure, high cholesterol, and prostate cancer. The supplements may have negative interactions with blood-thinning drugs, blood disorders, anti-platelet or anti-clotting medications, and some chemotherapy medications.
Glucosamine, Chondroitin And Blood Sugar
Using glucosamine and chondroitin to treat osteoarthritis may raise hemoglobin A1c and insulin levels in insulin-resistant people and diabetics. Taking a combination of glucosamine and chondroitin may affect blood sugar levels as well as interfere with the body’s ability to control blood sugar during surgery. Therefore, it’s important people who regularly use glucosamine and chondroitin and are preparing to have surgery performed, let their doctor know they are using the supplements, and stop taking them at least two weeks before they are scheduled to undergo the surgical procedure.
What Is Methylsulfonylmethane (MSM)?
Methylsulfonylmethane or MSM is a biologically active sulfur which the body produces naturally. It helps to provide the support needed by muscles and tendons all over the body. Sometimes called ‘The Miracle Supplement’, MSM is a nutrient the body needs to stay youthful and energetic. MSM works with Vitamin C to create healthily, new tissue aids collagen formation and improves complexion and skin health. It enhances skin, muscle tissue, and joint flexibility, helps detoxify the cells, speeds healing, dissolves degenerative disease causing calcium phosphate, and is an anti-inflammatory. MSM is often combined with glucosamine and chondroitin in alternative medicine.
Glucosamine MSM Side Effects
The joint health supplement Glucosamine MSM is designed to help the body produce collagen, synovial fluid, as well as other joint system building blocks that cushion and lubricate the cartilage, bones, ligaments and connective tissues while preventing helping to prevent inflammation. The glucosamine MSM combination can reduce joint stiffness, pain, and swelling and increase flexibility, range of motion, and mobility. Glucosamine MSM side effects include:
- Constipation
- Dehydration
- Diarrhea
- Foul Stools
- Gas
- Headaches
- Increased Thirst
- Insomnia
- Migraines
- Muscle Cramps
- Urine Retention

Side Effects Of Glucosamine Chondroitin MSM
The combination of glucosamine, chondroitin, and MSM is marketed as an effective treatment of osteoarthritis, other inflammatory joint diseases, and muscle damage suffered while doing exercise. Sold as a herbal supplement, the chondroitin, glucosamine, and MSM combination is manufactured using the standards for herbal compounds. Even though many people rave about the results they get using this combination of dietary supplements, there are several glucosamine chondroitin MSM side effects of which you should be aware of. They include:
- Bloating
- Constipation
- Diarrhea
- Drowsiness
- Gas
- Headache
- Heartburn
- Itching
- Nausea
- Puffy Eyelids
- Skin Irritation
- Stomach Cramps
- Swollen Ankles Or Feet
To safely use glucosamine, chondroitin, and MSM, carefully follow all the directions on the label and the package. Plus, discuss your allergies, medical conditions, and the medicines you use with your doctor to determine if it’s safe for you to use these supplements and avoid their side effects.