The dose of fluoxetine will be different for different patients and for different medical problems. Follow your doctor's orders. The following information includes only the average doses of fluoxetine. If your dose is different, do not change it unless your doctor tells you to do so.

For all indications, the doctor may need to prescribe a lower dose if you are elderly, have liver disease, or are taking other medications.

Depression

It may take 4 weeks before the full antidepressant effect of Prozac is seen.

Adults
The recommended starting dose is 20 milligrams a day, usually taken in the morning. If needed, the doctor may gradually increase the dose up to a maximum of 80 milligrams a day. The usual daily dose ranges from 20 to 60 milligrams. Daily doses above 20 milligrams should be taken in the morning or in two smaller doses taken in the morning and at noon.

Children 8 years and older
The usual starting dose is 10 or 20 milligrams a day. Children starting at 10 milligrams will have their dose increased to 20 milligrams a day after 1 week. Underweight children may need to remain at the 10-milligram dose.

Obsessive-compulsive disorder

It may take 5 weeks before the full effects of Prozac are seen.

Adults
The recommended starting dose is 20 milligrams a day, usually taken in the morning. If needed, the doctor may gradually increase the dose up to a maximum of 80 milligrams a day. The usual daily dose ranges from 20 to 60 milligrams. Daily doses above 20 milligrams should be taken in the morning or in two smaller doses taken in the morning and at noon.

Children 7 years and older
The recommended starting dose is 10 milligrams a day. After 2 weeks, the doctor will increase the dose to 20 milligrams. If needed, the doctor may further increase the dose up to a maximum of 60 milligrams a day. The recommended dosage range for underweight children is 10 to 30 milligrams a day.

Bulimia

Adults
The recommended dose is 60 milligrams a day taken in the morning. The doctor may start you at a lower dose and gradually increase it over a period of several days.

Panic disorder

Adults
The recommended starting dose is 10 milligrams a day. After 1 week, the doctor will increase the dose to 20 milligrams. If no improvement is seen after several weeks, the doctor may increase the dose to a maximum of 60 milligrams a day.

Premenstrual dysphoric disorder

Adults
The usual dose of Sarafem (a form of fluoxetine approved to treat premenstrual dysphoric disorder (PMDD)) is 20 milligrams a day. The doctor will instruct you to take the dose either every day of the month or only during the 2 weeks before menstruation begins (the luteal phase of your cycle). If there's no improvement after several weeks, the dose can be increased, usually to 60 milligrams a day. The maximum dose is 80 milligrams daily.