I did try the Cosamin, & it didn't work for me. The brand I use is Beyond a Century NAG, which comes as a bulk powder & is comparatively inexpensive.

Over the years I've tried ... MSM, NZ mussel, shark cartilage, Cetyl Myristoleate, Celadrin, Sam-E, Herbal Cox-2 inhibitors, Curcumin, Boswellia, Niacinamide, Vit. D (serum levels are great). And of course, the fish oil. Could be I've forgotten a few ... These were tried mostly for my knees, Dx severe OA at age 42, with rec. for knee replacement surgeries, one at a time.

I don't use MSM & Sam-E as much as I used to because they've become sedating. Never before. The Sam-E is really great for my knees at only 200 mg/day. Combined w/EPA concentrate FO, Sam-E was the best thing I'd ever found for my knees.

But for some reason, in the past few years, by day 3 of Sam-E at 200 mg. per day, I just want to sleep all day with my painfree knees. So that has become a bit impractical. And yes, I've come to believe that I may be the only person in the world who reacts to Sam-E this way. I'm guessing it's a sulfur thing. Have often wondered whether my acetylation, sulfation, & methylation Phase 2 pathways are a tad SNAFU'd.

If anyone has insight into the Sam-E sedation issue, or something I could do/take etc. to counteract this prob., please share. I've tried taking it at bedtime, but the sedation is 24/7 when I take it regularly & taking 100 mg., while less sedating, is also less helpful for the knees. They say some people have suffered ... hypomania from Sam-E?

Interesting post about the L-glutamine, mrsd. I had mostly heard about cysteine, taurine, and glycine being important for glutathione synthesis.