Azithromycin may take between one week (7 days) after starting treatment before you begin feeling better; however there are some people who feel much better within three days (3 days). It depends on how well your body responds but if you don't feel any improvement by day 7 then contact your doctor as they may want you taking longer than 7 days before deciding whether or not continuing treatment will help with your symptoms. . azithromycin can take up until 14 days after stopping treatment before symptoms return