I use the 10mg immediate release generic. There is a long acting one now which I will never try! I use this if I overdo at the gym, or somehow trigger some thing doing a big physical project, or recently like the root canal...which was keeping my neck turned toward the dentist as he did this thing..When I got home I was so STIFF and sore everywhere! So it was a Flexeril night. I use less than 30/yr to give you some reference. If I have days of pain, I will take 1/2 tablet for a short burst at bedtime. A full 10mg lasts me 2 days typically if I take it at bedtime (which is my worst time as usual)

People vary in response to drugs. Some are what we all slow metabolizers. I think I fall into this category. Medications typically blow me away... at least the pain ones and Valium type do. I take 1/2 of .25 Xanax for the dentist for premedication when big things are done. This blows me away for the whole day! Others can't believe this works for me.