Before You Take Osteo Bi-Flex for Osteoarthritis

What to know about the ingredients in this supplement

Osteo Bi-Flex is a dietary supplement that helps maintain joint health. It's often recommended as an over-the-counter treatment for people with knee osteoarthritis and is one of the best-known supplements in this category. 

As with any supplement, you should speak with your healthcare provider before taking Osteo Bi-Flex. Your medical history may indicate that it's not right for you, and it may interact with other medications.

It's also good to know what's inside this supplement and what scientific research says about the effectiveness of its ingredients. Because Osteo Bi-Flex is a supplement, it is not approved by the Food and Drug Administration. However, the components of the drug have been studied.

Man with knee joint pain
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Osteo Bi-Flex Ingredients

Osteo Bi-Flex offers a variety of formulations that contain multiple ingredients; each is a little different. However, the brand promotes a few compounds as the key ingredients.

  • Among these are:
  • "Joint Shield"
  • Glucosamine
  • Chondroitin sulfate
  • UC-II collagen
  • Methylsulfonylmethane (MSM)

Joint Shield

Osteo Bi-Flex promotes "Joint Shield" as its main ingredient, a proprietary blend of compounds that includes 5-Loxin Advanced—Boswellia serrata extract enriched with a compound known as 3-O-acetyl-11-keto-beta-boswellic acid (AKBA).

5-Loxin is reported to be beneficial for treating osteoarthritis of the knee. In one study, it reduced pain and improved physical function in osteoarthritis patients by controlling inflammation. Though researchers say it is safe, they err on the side of caution, saying that it may improve joint health.

"Joint Shield" is found in most Osteo Bi-Flex products, though they differ slightly in the secondary ingredients. Each of these also has been reported to have some positive effects on osteoarthritis symptoms to varying degrees.


Along with chondroitin, glucosamine has long been recommended as a treatment for osteoarthritis. Its actual effectiveness is under debate and can vary from one supplement manufacturer to another.

Glucosamine is a natural compound found in human cartilage that is responsible for fluid surrounding the joints. In supplements, glucosamine is either lab-generated or derived from shellfish shells. For people who have shellfish allergies, glucosamine could be problematic. It's important to read labels carefully if this is a concern for you.


Another natural compound found in the cartilage, chondroitin, helps retain water in joints. In supplements, the most common source of chondroitin is animal cartilage. 

Guidelines for Glucosamine and Chondroitin

Note that the American College of Rheumatology recommends against the use of glucosamine and chondroitin, given varying interpretations of the scientific evidence and lack of proven benefit. Discuss these guidelines with your healthcare provider before considering either supplement.

UC-II Collagen

This is undenatured type II collagen that has been known to support joint health. It is included in several Osteo Bi-Flex products. In supplements, it is most often derived from chicken sternum cartilage. UC-II collagen has shown positive results in independent studies of osteoarthritis treatment.

A study tested the effects of UC-II collagen in patients with moderate-to-severe osteoarthritis of the knee and found that patients who took UC-II collagen reported a significant improvement in physical function, stiffness, and pain compared with patients who were given a placebo or a combination of glucosamine hydrochloride and chondroitin sulfate.


Methylsulfonylmethane (MSM) is often sold alone as a dietary supplement for different health conditions, including osteoarthritis. Some Osteo Bi-Flex products contain it and typically say "with MSM" on the package.

MSM is a compound that contains sulfur, which is required by the body's connective tissues. It is thought to fight inflammation, though one study found the benefits to be minimal. It also notes that the clinical significance of MSM and osteoarthritis is unknown.

Supplements that are composed of only MSM have been known to have side effects, including upset stomach and diarrhea. Also, it should not be taken with blood thinners. Discuss this with your healthcare provider as the amount of MSM found in a particular Osteo Bi-Flex product might not be right for you.

Warnings and Interactions 

Just because a dietary supplement is sold over the counter does not necessarily mean it's safe for you.

Talk to your healthcare provider before taking Osteo Bi-Flex. There may be an ingredient in one of the various formulations that may be problematic given your medical history or medications and supplements you're taking.

Some potential concerns to be aware of:

  • Allergies: Shellfish allergies are a concern with some Osteo Bi-Flex products. Also, some people have allergic reactions to glucosamine (which can be derived from shellfish) or chondroitin.
  • Pregnant or nursing: It is recommended that people who are pregnant or nursing should consult their healthcare provider before taking any Osteo Bi-Flex products.
  • Drug interactions: The anticoagulants Coumadin (warfarin) and Mirador (anisindione) can interact with this product. If you take any medications, check with your healthcare provider before taking Osteo Bi-Flex.
  • Glaucoma: Glucosamine may increase eye pressure. If you have glaucoma, talk to your doctor before using Osteo Bi-Flex.
  • Overdose: Do not take other products that contain glucosamine or chondroitin while taking Osteo Bi-Flex. Doing so can result in an overdose. Signs of glucosamine toxicity include vomiting, diarrhea, jaundice, and lack of appetite. 
  • Blood sugar: Glucosamine can alter glucose metabolism. People with diabetes, prediabetes, or hypoglycemia should monitor their blood sugar more closely while taking products containing glucosamine.
  • Liver disease: People who have chronic liver disease should speak to their healthcare provider before taking products containing glucosamine. Research suggests glucosamine may be associated with elevated liver enzymes in people with pre-existing liver disease.

A Word From Verywell

Many people dealing with osteoarthritis have found some relief through the regular use of Osteo Bi-Flex. It is available in a variety of formulas, and most require just one or two caplets to be taken daily.

The American College of Rheumatology notes that these products might not work for everyone and emphasizes that since these products are not checked by the FDA, they might have serious side effects.

While there are studies that back up the benefits of some ingredients found in Osteo Bi-Flex, the supplements themselves have not been tested. Now that you know what's inside this supplement, you can have an informed conversation with your healthcare provider about whether they're right for you.

Frequently Asked Questions

  • What are the side effects of Osteo Bi-Flex?

    Potential side effects of Osteo Bi-Flex include bloating, constipation, diarrhea, gas, hair loss, nausea, puffy eyelids, and stomach pain. Rarer, but more serious side effects include irregular heartbeats, swelling in the legs, and allergic reactions.

  • Does Osteo Bi-Flex repair joint damage?

    Possibly, but not likely. There's some evidence the individual ingredients of Osteo Bi-Flex may benefit joint health, improve mobility, and reduce pain. However, there's no before-and-after research involving imaging that confirms the reversal of joint damage.

  • Does Osteo Bi-Flex affect the kidneys?

    Possibly. Research in animals suggests that moderate to large doses of glucosamine, one of the main ingredients in Osteo Bi-Flex, may cause kidney damage. However, it is unclear whether or not it has the same effect in humans.

  • Does glucosamine cause weight gain?

    It's unclear. In animal studies, glucosamine caused weight gain in rodents fed a standard diet but not in those on a high-fat diet. Glucosamine may promote insulin resistance, which is linked to weight gain. Research in humans is needed.

15 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Carol Eustice
Carol Eustice is a writer who covers arthritis and chronic illness. She is the author of "The Everything Health Guide to Arthritis."