Will fluoxetine start to make me feel better within a week?

Probably not. Fluoxetine, also known as prozac, (fluoxetine) has biochemical properties that lead it to last a long time. The down side of this is that it takes a longer time to be effective - for most people it takes 4-6 weeks. Other antidepressants in the same family like citalopram/celexa, escitalopram/lexapro and sertraline/zoloft take effect in a shorter period of time for most.