Chlamydia is treated with a short course of antibiotics, and the infection clears completely in the vast majority of cases. The standard treatment is doxycycline, taken twice daily for seven days. Most people feel no different during treatment because chlamydia often causes no symptoms to begin with, but the antibiotics work quickly to eliminate the bacteria.
Standard Antibiotic Treatment
Doxycycline is the preferred first-line treatment for uncomplicated chlamydia affecting the genitals, rectum, or throat. You take it twice a day for seven days. An alternative is a single, larger dose of azithromycin taken all at once, which can be useful if sticking to a week-long regimen is difficult. Both antibiotics are highly effective, though doxycycline has become the preferred choice in current guidelines, particularly for rectal infections where azithromycin has shown somewhat lower cure rates.
A few practical things to know about doxycycline: it can cause nausea, especially on an empty stomach, so taking it with food helps. It also makes your skin more sensitive to sunlight, so you may burn more easily during the week you’re on it. Avoid lying down right after swallowing the pill, as it can irritate the esophagus. These side effects are mild and temporary.
There is currently no significant antibiotic resistance in chlamydia, unlike some other sexually transmitted infections. That means treatment failure is rare. If symptoms persist after completing the full course, the more likely explanation is reinfection from an untreated partner rather than the medication not working.
Treatment During Pregnancy
Doxycycline is not safe during the second and third trimesters of pregnancy because it can affect the developing baby’s teeth. For pregnant individuals, the CDC recommends azithromycin as a single oral dose instead. An alternative is amoxicillin taken three times daily for seven days. Erythromycin, which was previously used, is no longer recommended due to frequent gastrointestinal side effects and some evidence linking it to adverse outcomes in children.
When You Can Have Sex Again
The timeline depends on which treatment you received. If you took the single-dose azithromycin, wait at least seven days before having sex again. If you’re on the seven-day course of doxycycline, wait until you’ve finished every dose. Having sex before the infection fully clears puts your partner at risk and can lead to a cycle of reinfection between you.
This waiting period applies to all forms of sexual contact, not just intercourse. Using condoms during this window is not considered a reliable enough substitute for simply waiting.
Getting Your Partner Treated
Treating your partner is not optional if you want to stay clear of chlamydia yourself. Reinfection from an untreated sexual partner is one of the most common reasons people test positive again shortly after treatment. Anyone you’ve had sex with in the past 60 days should be tested and treated.
In many states, a practice called Expedited Partner Therapy allows your provider to write a prescription for your partner without examining them first. This is specifically designed for situations where your partner can’t easily get to a clinic. It’s not a replacement for a full medical visit, but it removes a barrier that often leads to partners going untreated. Your provider can tell you whether this option is available where you live.
Follow-Up Testing
You don’t necessarily need a “test of cure” immediately after finishing antibiotics, since the medication is so effective. What you do need is retesting three months later. The CDC recommends this three-month retest for everyone treated for chlamydia, regardless of whether symptoms have returned. The purpose is to catch reinfection, which is common. If you can’t make the three-month window, getting retested anytime within the following year still provides value.
If you test too soon after treatment (within a few weeks), you may get a false positive. Remnants of dead bacteria can still trigger a positive result on the nucleic acid tests used for chlamydia screening, even though the infection is gone.
What Happens if Chlamydia Goes Untreated
Because chlamydia frequently causes no symptoms, many people carry it without knowing. This is exactly what makes it dangerous. Mathematical modeling estimates that about 22% of women with untreated chlamydia will develop pelvic inflammatory disease (PID), an infection of the uterus, fallopian tubes, or ovaries. PID can cause chronic pelvic pain, scarring of the reproductive tract, and infertility. It can also increase the risk of ectopic pregnancy, where a fertilized egg implants outside the uterus.
In men, untreated chlamydia can spread to the tube that carries sperm, causing pain and swelling in one or both testicles. While less common, this can also affect fertility. For anyone, an active chlamydia infection makes you more susceptible to contracting HIV if exposed.
The good news is that treating chlamydia promptly prevents nearly all of these complications. The infection itself causes no permanent damage when caught and treated early. Routine screening, especially for sexually active women under 25, is the most reliable way to catch it before it causes problems.
Rectal and Throat Infections
Chlamydia doesn’t only infect the genitals. It can also develop in the rectum (from receptive anal sex) or the throat (from oral sex). Rectal chlamydia may cause discharge, pain, or bleeding, but it’s often asymptomatic. Throat infections almost never cause noticeable symptoms.
Doxycycline for seven days is the preferred treatment for both of these locations. This is one area where the choice of antibiotic matters: azithromycin has been shown to be less effective for rectal chlamydia than doxycycline. If you’ve been diagnosed with a rectal infection specifically, completing the full seven-day doxycycline course is important. Standard genital screening won’t detect infections at these other sites, so if you’ve had oral or anal sex, let your provider know so they can test the right areas.