Even though it takes Lexapro only a few hours to increase serotonin levels within the brain, it may take several weeks to start working. Signs that Lexapro has started working include an improvement in your sleep, energy, or appetite. In some, this may happen in as little as 1 to 2 weeks. Relief from symptoms, such as a depressed mood or a lack of interest in activities you used to enjoy, may take up to 6 to 8 weeks to fully improve.

How long can you take Lexapro?

If this is your first episode of depression, your doctor may prescribe Lexapro for a set period, for example, 6 months to a year. Some people with persistent depression may need to take it for many years. There are no known problems when Lexapro is taken long-term.