Does taking flexeril (cyclobenzaprine hcl) cause weight gain?

I have not seen this: That is not a side effect that I have seen. Sedation is the most common side effect in my opinion.

No: If the Flexeril (cyclobenzaprine hcl) is being taken due to muscle spams or pain, then it's more likely that the weight gain is resulting from a decrease in activity and altered eating habits. Weight gain is not considered a typical side effect of the medication. A rare incidence has been reported but no causal relationship to the drug has been established. So as a general rule, don't consider fexeril as the culprit.