Cosamin DS does get the doses of glucosamine and chondroitin sulfate right, but so do a lot of other supplements at half it's price point. Beyond that adding in a minimal amount of vitamin C and Manganese isn't going to make much difference to the products performance at all.
Considering that there's a host of other joint health supplements on the market that do this with additional extras we can't recommend it. If you want something with a dose of glucosamine HCL as high as cosamin DS then we'd recommend Osteo Bi Flex Triple Strength, which contains this but with added boswellia and curcumin. However, if you're looking for something that is a better all around joint supplement then FlexAgain is hands down a better option than Cosamin DS. The dose of glucosamine is a little lower, but the 11 ingredients in FlexAgain more than make up for it, with you ultimately getting 4 times as many full capsules for your money, with ingredients that are in many cases more effective.
We should note that whilst chondroitin sulfate has been shown to boost the effectiveness of glucosamine it doesn't actually do anything by itself and the results in clinical trials are actually pretty mixed as to whether it does anything at all. So we wouldn't say it's essential for a good joint supplement.
All in all there's better options available.
We'd actually rate cosamin ASU a bit higher than Cosamin DS, in that whilst the backbone of the supplement is the same, it does include added boswellia. But, beyond that there's functionally no evidence to suggest that a tiny hint of avacado and soy extracts will have any benefits to joint health.
Verified customers Cosamin reviews are generally ok to positive, we're not overly surprised as we've already stated the supplement should work. There's just much better options available. There are some complaints of Cosamin side effects which do seem to be reasonable as nausea is a known potential side effect of glucosamine HCL in higher dosages.
All in all we don't really see much issue with them having generally good reviews as the ingredients are within clinically studied doses and customers citing that it has worked for knee pain and most other common types of joint pain isn't a surprise. So unlike a lot of supplements these do seem to be legitimate and there's no reason to believe the reviews have been faked.
Vitamins - 6% of your recommended daily intake of vitamin C doesn't really add much to your health in general let alone being enough to add anything to a joint health supplement. As for the 1mg of manganese could theoretically boost the effectiveness of Glucosamine slightly. The studies are pretty much 50/50 on this though and the reality is that the sample sizes are pretty small and we wouldn't say that it adds up to much meaning that Cosamin DS would've been better off including some known joint health related vitamins instead of these small amounts. For example vitamin D is essential for joint health and almost 60% of US adults over 40 are deficient in vitamin D which can cause joint pain all by itself.
Glucosamine HCL - Glucosamine HCL is a purer form of glucosamine sulphate, it is more likely to have mild side effects like nausea, but a dose of 1500mg is almost equivalent to 2500mg of it's counterpart. This means that Cosamin DS can get more into a smaller capsule. There are less studies directly demonstrating it's effectiveness so typically in countries where glucosamine is available on prescription for issues like knee or hip pain sulphate is used. There are enough studies to suggest that HCL is effective however, although whether or not some of the difference is lost due to it being less easily absorbed by the body is up for debate. It should be noted meta analysis of multiple trials shows that whilst Glucosamine reduces pain in joints, it doesn't do much to improve overall health. Some studies initially looked promising that it reduced joint space narrowing this doesn't seem to have been effectively replicated. Still a decent ingredient for Cosamin DS.
Chondroitin - Chondroitin is in a lot of joint health supplements and we think it is a fair inclusion in Cosamin DS, the problem is that there have been a few studies that have suggested it isn't as effective at improving the performance of Glucosamine as originally hoped. This doesn't mean it's a bad inclusion in Cosamin DS, in fact it's quite common for supplements of their type.
As you can see we're not really dealing with a lot here in the way of ingredients in Cosamin DS. The fact is it's pretty much just a glucosamine & chondroitin supplement. And there's nothing wrong with that, except for the fact you can pick that up for $20-30 for a month supply with a generic brand. And as US supplements have to be 3rd party lab tested, Cosamin DS won't be anything special when compared against those. The vitamin choice was disappointing.