It can take around 4 to 6 weeks to fully appreciate the effectiveness of most antidepressants. If you are experiencing persistent side effects after 2 weeks of treatment, there is a possibility that they may continue. Your pharmacist can help adjust your dosage if needed. When transitioning from one antidepressant to another, factors such as dosage and duration of treatment will influence the timing. Your pharmacist can assist in minimizing side effects and creating a smooth transition plan while closely monitoring your progress.