Glucosamine and chondroitin for knee pain treatment

Posted on September 1, 2011


Something I’m often asked by people who have knee pain is if there is any supplement, food, pill, etc. they can take to alleviate their pain.

One of the supplements most often referenced for knee pain / arthritis is glucosamine and chondroitin.

To be blunt, the majority of supplements are absolute crap. You might as well see how far you can shoot your money into a trash can. Either way your money ends up in the same place, but at least with the latter you have a little fun. However, I have had plenty of people tell me they have benefited by taking glucosamine and chondroitin…but I’ve also heard people claim this “thing” gave them “the ripped abzzz.”

So does G & C actually do anything to help relieve arthritis and or pain in the knees?

Hopefully through the following studies I’ll be able to shed some light as to whether this supplement is worthwhile.

It’s rare I see glucosamine and chondroitin sold separately, although it is easy to find if you really want to. And it is rare I hear people taking one or the other and not the combination.

Because of that, and to make things simpler, I’m only going to look at the results of the following studies regarding taking the combination. Also, rather than do a full review of each study, I’m just going to steal some of the most pertinent quotes and data from each and chime in when I see fit.

Let’s get to it, the first study:

Glucosamine, Chondroitin Sulfate, and the Two in Combination for Painful Knee Osteoarthritis

In terms of pain reduction:

“Overall, differences between placebo and the various agents were relatively small. Analysis of the primary outcome measure revealed that the rate of response to glucosamine and chondroitin sulfate was not significantly higher than the rate of response to placebo.”


“As compared with the rate of response to placebo the combination of glucosamine and chondroitin sulfate was 6.5 percentage points higher.”


“The OMERACT–OARSI [this is another way to test osteoarthritis pain] response rates showed a similar pattern, with differences between the placebo group and the combined-treatment groups not reaching significance. As compared with the rate of response to placebo the rate of response to combined treatment was 8.7 percentage points higher.”

It’s important to note in this study it was found when patients in mild pain were compared to moderate-to-severe pain patients, moderate-to-severe patients had much better outcomes with the use of supplementation.

Also, while the mild pain group did not have a statistically significant difference between placebo and supplementation, there was still a difference favoring supplementation (this is a theme in these studies).

You can see supplementation was better than placebo in every category. Often times it was barely better, and maybe not clinically relevant, but it was still better.


The Effect of Glucosamine and/or Chondroitin Sulfate on the Progression of Knee Osteoarthritis

The two most common ways these studies seem to assess the efficacy of glucosamine and chondroitin is pain reduction (such as the study above) and joint space width. In many individuals with knee pain / arthritis there is a reduction in the space between the knee. Supplementation is considered to be beneficial if it helps prevent this reduction.

This study used what is called the Kellgren-Lawrence grading scale to group subjects. There are four grades:

Grade 1: doubtful narrowing of joint space and possible osteophytic lipping

Grade 2: definite osteophytes and possible narrowing of joint space

Grade 3: moderate multiple osteophytes, definite narrowing of joints space, some sclerosis and possible deformity of bone contour

Grade 4: large osteophytes, marked narrowing of joint space, severe sclerosis and definite deformity of bone contour

The researchers decided to only use Grade 2 and Grade 3 scales. If you’re curious here is what an X-Ray comparing a Grade 2 to a Grade 3 looks like:

This is important because in this study,

”K/L Grade 2 showed less JSW loss while Grade 3 showed more JSW loss in supplemented group.“

Therefore, it appears supplementation may only be beneficial for groups who have attained a certain level of arthritis. And for other groups who have already reached a certain point supplementation may actually be harmful and accelerate their arthritis.


Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis

Pretty similar story here,

“no statiscally significant differences nor clinically relevant differences were found.” However, when given separately supplementation still consistently outperformed placebo. Combination therapy performed the same though.

Click to enlarge:



Ok, so the overriding theme in these studies, I think, is glucosamine / chondroitin supplementation is consistently found to have a small, possibly but often not statistically significant effect. One which is nearly always better than what is found in the placebo group.

In other words, it helps with knee pain but multiple studies claim it is not statistically significant nor clinically relevant.

Good quote from one of the papers:

“Statistical significance should not, however, be confused with clinical relevance.”

Based on the fact supplementation pretty much always bests the placebo group and the amount of people who have told me the relief they have gotten from the supplement, maybe the studies need to redefine what is clinically relevant? I really don’t know if they do or not, but there is little doubt the supplement is doing something.

Perhaps some are responders for one reason and others are not. The first study showed those with mild arthritis knee pain only got a little relief. The second study showed those with pretty severe arthritis didn’t get any relief. Leaving those in the middle of the two to get the biggest relief. Perhaps more studies need to be done dealing with this middle group?

I obviously don’t know for sure, and the thing I found at the end of tons of papers on this subject is a conclusion to the effect of, “We need more studies” illustrating a lot of people aren’t sure.

This quote sums things up well:

We are confident that neither of the preparations is dangerous. Therefore, we see no harm in having patients continue these preparations as long as they perceive a benefit and cover the costs of treatment themselves. Coverage of costs by health authorities or health insurers for these preparations and novel prescriptions to patients who have not received other treatments should be discouraged.”

What a, gasp!,, logical approach to healthcare: There is some effect noted and people report a benefit from the supplement, however it is at this time not considered clinically relevant. Therefore it is hard to justify an insurance company paying for it. If you don’t mind paying for the supplement yourself, there isn’t any reason not to do so.

I’ll add GC supplementation seems to be worthwhile for those looking to alleviate some of their knee pain. Unless you have severe arthritis there doesn’t seem to be much reason to not take it. It’s not very expensive, and it is definitely doing some beneficial things. Just don’t rely on it as your only, nor primary, pain reliever.


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Posted in: Knee Pain, Pain