Lexapro (escitalopram) typically starts to work within 1 to 2 weeks for some initial improvements like better sleep, energy, and appetite. However, it usually takes about 4 to 6 weeks, and sometimes up to 6 to 8 weeks, to feel the full benefits for symptoms of depression and anxiety. Individual response times vary, and some people might notice improvements sooner, while others may take longer to experience the full effects. It is important to continue taking Lexapro as prescribed, even if improvements are not immediately noticeable. Side effects during the first week may include nausea, headache, drowsiness, and others, but these often diminish with time.