Chlamydia is treated with a short course of oral antibiotics, and the infection clears in the vast majority of cases. Doxycycline, taken twice daily for seven days, is the current first-line treatment recommended by the CDC. Most people feel no different during treatment since chlamydia often causes no symptoms to begin with, but the antibiotics work quickly to eliminate the bacteria.
The Standard Antibiotic Course
Doxycycline is the preferred antibiotic for uncomplicated chlamydia infections in both men and women who are not pregnant. The regimen is straightforward: one pill twice a day for seven days. It’s important to finish the entire course even if you feel fine, since stopping early can leave the bacteria partially alive and the infection unresolved.
Azithromycin, a single-dose antibiotic that used to be the go-to option, is now considered an alternative rather than first choice. The shift happened because doxycycline consistently produces higher cure rates, particularly for rectal chlamydia infections. Some studies have reported treatment failures with azithromycin, though research published in Antimicrobial Agents and Chemotherapy found that genetic mutations once thought to signal azithromycin resistance actually predate the drug’s clinical use, meaning true resistance isn’t a major concern yet. Still, doxycycline’s superior track record has made it the default.
Treatment During Pregnancy
Doxycycline is not safe during pregnancy because it can affect fetal bone and tooth development. Pregnant women are treated with alternative antibiotics that are safe for both mother and baby. The key difference in pregnancy is that a follow-up test (called a test of cure) is recommended about four weeks after finishing treatment to confirm the infection has fully cleared. This extra step matters because an active chlamydia infection during delivery can pass to the newborn, potentially causing eye infections or pneumonia.
What to Do After Treatment
You should avoid sex for seven days after completing treatment (or seven days after a single-dose antibiotic, if that’s what was prescribed). This waiting period gives the medication time to fully clear the bacteria and prevents you from passing the infection to a partner or getting reinfected by one.
A routine test of cure isn’t necessary for most non-pregnant people who complete their full antibiotic course. The exception is if your symptoms don’t go away, you weren’t able to take every dose, or you think you may have been reinfected. What is recommended for everyone, though, is retesting about three months after treatment. This isn’t to check whether the antibiotics worked. It’s to catch reinfection, which is common, especially if a sexual partner wasn’t treated at the same time.
Why Your Partner Needs Treatment Too
Treating yourself without addressing your sexual partner is one of the most common reasons people end up with chlamydia again shortly after finishing antibiotics. Reinfection from an untreated partner accounts for a significant share of repeat positive tests.
To solve this problem, many states allow something called Expedited Partner Therapy (EPT). This means your healthcare provider can give you extra medication or a prescription to hand directly to your partner, even if that partner hasn’t been examined. The CDC considers EPT a useful option for partners of people diagnosed with chlamydia, particularly for male partners of women. Not every state permits it, so your provider will know what’s available where you live. At minimum, any recent sexual partners should be notified and encouraged to get tested and treated on their own.
What Happens If Chlamydia Goes Untreated
Because chlamydia frequently causes no symptoms, many people carry the infection for weeks or months without knowing. That silent period isn’t harmless. In women, untreated chlamydia can spread from the cervix into the uterus and fallopian tubes, causing pelvic inflammatory disease (PID). Data from randomized screening trials estimate that about 17% of women with untreated chlamydia develop PID, which can lead to chronic pelvic pain, scarring of the fallopian tubes, and fertility problems. The risk isn’t inevitable, but it’s high enough that screening and early treatment make a real difference.
In men, untreated chlamydia can cause epididymitis, a painful inflammation of the tube that stores sperm behind the testicle. While less likely to affect long-term fertility than PID, it’s uncomfortable and entirely preventable with a simple course of antibiotics. For both sexes, having an active chlamydia infection also increases susceptibility to other sexually transmitted infections, including HIV.
Rectal and Throat Infections
Chlamydia doesn’t only infect the genitals. It can also be contracted in the rectum (through receptive anal sex) or the throat (through oral sex), though throat infections are less common and often clear on their own. Rectal chlamydia is particularly worth noting because it’s where the difference between doxycycline and azithromycin is most pronounced. Doxycycline is significantly more effective at clearing rectal infections, which is one of the reasons it became the preferred treatment across the board. The seven-day course of doxycycline is used for rectal chlamydia just as it is for genital infections.
How Testing Works
Chlamydia is diagnosed with a nucleic acid amplification test (NAAT), which detects bacterial DNA. For genital infections, this is typically a urine sample or a swab. Rectal or throat infections require a swab from the relevant site. Results usually come back within a few days, and many clinics will start treatment before results are confirmed if symptoms or exposure history strongly suggest infection.
If you’re retesting at the three-month mark, the same type of test is used. Just be aware that testing too soon after treatment (within a few weeks) can sometimes pick up dead bacterial DNA and give a false positive, which is why the CDC advises waiting at least four weeks for any test of cure and three months for routine retesting.