Decay/Reactivity of DMSO and MSM

[Mk]

How long can one store dimethyl sulfoxide (DMSO) or methylsulfonylmethane (MSM)?

 

[Moonbear]

I don't have any experience with MSM, but have never had DMSO go bad. DMSO is one of those things we use a little bit every few years, and then sits on a shelf in between, and still seems just fine. I've known a few people to store it in the fridge if stored a long time, rather than at room temp (so it will freeze), but I haven't noticed any difference between the two storage methods other than the nuisance of having to wait for it to thaw when taken out of the fridge.