A 3-day course of doxycycline is not considered the recommended treatment for chlamydia. The Centers for Disease Control and Prevention (CDC) recommends a single dose of azithromycin or a 7-day course of doxycycline as the standard treatment for chlamydia.
However, some studies have suggested that shorter courses of doxycycline may be effective for treating chlamydia. For example, a study published in the New England Journal of Medicine found that a 3-day course of doxycycline was as effective as a 7-day course for treating chlamydia in men. Another study published in the journal Sexually Transmitted Diseases found that a 5-day course of doxycycline was effective for treating chlamydia in women.
While these studies suggest that shorter courses of doxycycline may be effective for treating chlamydia, it is important to note that the CDC still recommends the standard treatment of a single dose of azithromycin or a 7-day course of doxycycline. If you think you may have chlamydia, it is important to talk to a healthcare provider who can evaluate your symptoms and recommend appropriate treatment.