Is the effective prozac (fluoxetine) dosage usually 20mg? i had a doctor tell me 20mg used to be the only prozac (fluoxetine) dose and going higher isn't necessary

That depends: Doctors used extremely high doses of prozac (fluoxetine) when it first came out. Now the maximum dose is 80 /mg per day. However, depending on the condition - 20mg is a pretty common effective dosage. Off label dosing can still be considered.

Prozac (fluoxetine): The usual edose for Prozac (fluoxetine) is 20 mg. However, some people do require a higher dose if only part of the desired effect is reached. In my practice, if the patient requires more than 40 mg, I seek a consultation from a psychiatrist to determine if their are other psychiatric problems that need to be addressed and, perhap, new medication to fit that particular patient