It's a muscle relaxer, not as strong as flexaril.
I have taken it a few times. It did nothing for my TMJ, but did help my back some when I was having some muscle spasms there.
I didn't get much in the way of side effects except when I have been really tired.
Then it just made me feel really mellow. Nothing really weird though, it's not a narcotic.
What are you taking it for?
Hope this helps!