Took 5mg of prozac (fluoxetine) for 6 days. how many days would it take to leave my system?

Less than a week: The usual starting dose for fluoxetine (Prozac) is 20 mg, so you were on a VERY low dose, so after 6 doses there is not very much med in your body. The time for 1/2 the medicine to be eliminated from the body in a healthy person is 3 days at most, so it would take about 6 days for the last dose to be completely eliminated. It may be gone sooner depending on how quickly your liver metabolizes it.