There is no chemical difference. I have read that a chemist cannot determine if a sample of MSM is oranic or inorganic. Buy the least expensive, which I have found to be the organic Lignisul bulk powder. I pay about 16 USD with shipping for a 1 lb (about half a kilo) tub.
I put a heaping teaspoon ( approx. 4 grams) into a cup of coffee or hot tea as it goes into solution almost instantly that way. Cold fruit juices mask the taste better but any thing you put it in will have a bit of bitter taste, fruit juice being the least offensive.
I can tell you that is has made my hair and nails grow faster, I cannot say it has made new hair. Also it has had some very positive effects on joint pain and my skin and my gums. Supposedly it helps all connective tissue.
Which has encourged me and led me to experiment with it topically on the scalp. I plan to post a summary of my results in the future. To me it is very promising on several fronts. Time will tell and all my research indicates it is as harmless a pure water.