My fiance has taken it for 6 years now. It was the best meication he used. No weight gain, etc. However, drowsiness has been an issue, and he feels (and his doctor said) that he is starting to see the beginning signs of retardive dyskinesia. To cope, since he has a mild case, he has been able to greatly decrease the amount he has been taking and was originally prescribed. (6 a day to two to three a day). He noticed the first time he used it he was very tired (like he had been drugged) - but since then had gotten used to it. If he feels a bit off during one day he may take one extra. If he plans on staying up late (like on a friday night) he may take it later becuase of the drowsiness side effect.
hope this helps a little- Good luck.