ibromyalgia
"This muscle relaxer is very good at relaxing my muscle if taken for several days; it is slow acting.  The negative side is that my doctor only lets me take it when I have a flare-up, so I have to take it about 4 days before I get any relief and then when I stop taking it, it stays in my system for about 3 days and then I go right back to my normal baseline level of pain.  I wish I could take it everyday because I feel so much less pain overall when I have it built up in my system."