Chlamydia is treated with a short course of antibiotics, most commonly doxycycline taken twice daily for seven days. Treatment is highly effective, and the infection typically clears completely within a week or two of finishing the medication.
The Standard Treatment
Doxycycline is the preferred first-line treatment for chlamydia in adults and adolescents. The typical regimen is a 100 mg dose taken twice a day for seven days. This applies to infections of the genitals, rectum, and throat.
Doxycycline replaced azithromycin (a single-dose antibiotic formerly used as the go-to option) as the preferred treatment because it has higher cure rates, particularly for rectal chlamydia infections. Azithromycin, taken as a single one-gram dose, is still used as an alternative when doxycycline isn’t an option, but it’s no longer the first choice.
Treatment During Pregnancy
Doxycycline is not safe during pregnancy because it can affect fetal bone and tooth development. Pregnant individuals are typically treated with azithromycin instead. Amoxicillin is another option that may be used during pregnancy. Testing after treatment is particularly important for pregnant people, since untreated chlamydia can lead to preterm birth and transmission to the baby during delivery.
What Treatment Feels Like
The most common side effects of doxycycline are digestive: nausea, diarrhea, and stomach upset. Taking it with food and a full glass of water helps reduce these symptoms. One notable side effect is increased sun sensitivity, meaning your skin burns more easily while you’re on the medication and for a few days after. Wearing sunscreen or limiting sun exposure during treatment is a good idea.
Some women develop a vaginal yeast infection during or after the antibiotic course, since the medication can disrupt the normal balance of bacteria. This is usually mild and treatable with over-the-counter antifungal products.
What to Do After Treatment
You need to avoid sex for seven days after starting treatment (or until the full seven-day course is finished and any symptoms have resolved). This window prevents you from passing the infection to a partner before the antibiotics have fully cleared it.
The CDC recommends retesting three months after treatment. This isn’t because the antibiotics failed; it’s to catch reinfection, which is common. If your partner wasn’t treated, or if you have a new partner, the risk of getting chlamydia again is significant. Anyone who tests positive for chlamydia should be rescreened at that three-month mark.
Getting Your Partner Treated
Your sexual partners need treatment too, even if they have no symptoms. Most chlamydia infections are asymptomatic, so a partner can carry and transmit the bacteria without knowing it. If your partner doesn’t get treated, you’re likely to get reinfected.
One option is expedited partner therapy (EPT), where your healthcare provider gives you a prescription or medication to bring directly to your partner without requiring them to come in for a separate appointment. EPT is legal in most U.S. states and is especially useful when a partner is unlikely to seek care on their own. It doesn’t replace a full clinical visit for the partner, but it’s a practical backup when access is a barrier.
Treatment for Newborns
Babies born to mothers with untreated chlamydia can develop eye infections (chlamydial conjunctivitis) or, less commonly, pneumonia. The standard treatment for newborns with chlamydial eye infections has shifted toward azithromycin rather than erythromycin. While erythromycin was used for decades, azithromycin is now preferred because erythromycin carries a risk of causing a condition called pyloric stenosis, a narrowing of the stomach outlet that can require surgery. Azithromycin given once daily for three days has shown cure rates around 86% in small studies, with a more favorable safety profile.
When Treatment Doesn’t Work
True treatment failure with doxycycline is rare. When people test positive again after treatment, the most common explanation is reinfection from an untreated partner. Other possibilities include not completing the full course of antibiotics or having sex before the seven-day waiting period was up.
If the infection persists despite proper treatment, alternative antibiotics like levofloxacin may be used. Your provider may also test for other infections that can look similar or co-occur with chlamydia, particularly gonorrhea, which often overlaps.