Is prozac (fluoxetine) still effective after 4 years?

Often, yes.: If you mean can Prozac (fluoxetine) still be effective after taking it for four years? The answer would be yes. For some, symptoms can recur while on an antidepressant for many reasons. They can be under more stress, they miss too many doses and often, unfortunately the symptoms were not fully treated and the condition intensifies. Sometimes, ssris like Prozac (fluoxetine) do quit working and a change of med is needed.

Prozac (fluoxetine): Yes. I have seen patients who have been on Prozac (fluoxetine) for more than 10 years who still benefit from it.