A new study analyzed the effects of Lexapro, a selective serotonin reuptake inhibitor. Lexapro is a common antidepressant, acting on the serotonin levels which we know as reuptake sites. It inhibits serotonin recycling in these parts of the brain which allows us to retain more serotonin so that symptoms of depression are reduced. For most people, it takes medicating with Lexapro and other SSRI’s for around 4 weeks for its full effects to be felt.