Bests & Worsts Reviews from Amazon

I've been taking this supplement for over a year, but I take so many other supplements, couldn't say whether I had benefit from it or not. I do have thin hair and it had not helped it become thicker. I came across an article about an actor who struggled with severe arthritis pain for 20 years and became pain free using MSM. The article stated that many brands contain fillers and little MSM. There is a purity test. Empty the contents of one capsule into a clear glass of water. The MSM will sink to the bottom and completely dissolve within a few minutes. I still have the Nature's Way capsules, so I did the test, and nothing fell to the bottom. All of it was fluffy and floated on top of the water. It wouldn't even dissolve when I mixed it with a spoon. Then I took a teaspoon of MSM from Vita Flex which I had purchased for my horse. It has weight to it and is crystalline. It is supposed to be 99% pure. All of it sunk to the bottom of a glass of water. I've logged in to Amazon, written this review, and just went back to check and the Nature's Way stuff is still floating on top of the water and has formed a film. This does not inspire confidence in the brand. It would be great to have a place to send supplements to test for purity. It is interesting that there are more positive than negative reviews here. But this whole purity test has put doubts in my mind.