I stopped taking MSM last year. I used to take 1000-2000mg daily. The doses were so strong that they messed up my menstrual cycle. That time I was also taking 2500-5000 mcg of biotin. After reading this thread I decided to try MSM again, but in power form so I can control the dose. I think I'll just drop a little under 1/4 tsp in my water bottle daily. I'm also taking 500 mcg of biotin now, so I'm hopefully that the combo of both won't mess me up again since it's in lower doses.
I also have bad sinus problems but I don't remember noticing a difference in my sinus headaches/sinusitis/allergies last year when I was taking large doses of MSM. I do remember sneezing a lot though, but I'm not sure if that had anything to do with MSM
. I'm going to see if I notice a change this time.