Chlamydia is curable with antibiotics. The CDC-preferred treatment is doxycycline 100 mg by mouth twice daily for 7 days CDC, 2021. A single dose of azithromycin or a course of levofloxacin are alternatives. Take the full course, treat your partners, and retest in about three months to catch reinfection.
| Item | Reported cases |
|---|---|
| Chlamydia | 1,648,568 |
| Gonorrhea | 601,319 |
| Syphilis (P&S) | 53,007 |
How chlamydia is treated
Chlamydia is caused by the bacterium Chlamydia trachomatis, and most US genital infections come from serovars D–K. It's the most commonly reported bacterial STI in the country, with about 1.65 million reported cases in 2023, a rate of roughly 492 per 100,000 that has stayed roughly flat across 2020–2023 CDC AtlasPlus, 2023. The right antibiotic clears it.
Current guidance names doxycycline 100 mg orally twice daily for 7 days as first-line for most non-pregnant adults CDC Tx Guidelines. Doxycycline is a tetracycline antibiotic that blocks the bacterium's ability to make the proteins it needs to multiply, so the infection clears as your immune system mops up what's left.
When doxycycline isn't a good fit, the alternatives are azithromycin 1 g orally as a single dose, or levofloxacin 500 mg orally once daily for 7 days. Single-dose azithromycin is convenient, but it was downgraded from co-equal status because microbiologic treatment failure in men ran higher than with doxycycline, and doxycycline is markedly more effective against rectal infection. In a randomized trial, doxycycline cured 100% of rectal chlamydia versus 74% for single-dose azithromycin Rectal CT RCT, the main reason the 2021 guidelines moved doxycycline to first-line.
Treatment in pregnancy
Doxycycline isn't used in pregnancy. The preferred regimen is azithromycin 1 g orally as a single dose, with amoxicillin 500 mg three times daily for 7 days as an alternative. Treating chlamydia during pregnancy matters because the bacterium can pass to the baby at delivery, where it's a leading cause of early infant pneumonia and conjunctivitis (eye infection in the newborn).
A note on LGV
Lymphogranuloma venereum (LGV) is a more invasive form caused by C. trachomatis serovars L1, L2, and L3, with the highest burden among men who have sex with men. It usually shows up as proctocolitis: mucoid or bloody rectal discharge, anal pain, and tenesmus (the constant feeling of needing to pass stool). LGV needs a longer course of doxycycline 100 mg twice daily for 21 days, with azithromycin or erythromycin as alternatives CDC LGV. Partners from the prior 60 days get presumptive doxycycline 100 mg twice daily for 7 days.
What treatment is actually like
Doxycycline is a 7-day course of pills. Take it with food, since it can upset an empty stomach, and stay out of strong sun, because it makes some people more prone to sunburn. Finish every dose even if symptoms ease in a day or two, since stopping early is one of the most common reasons an infection lingers.
Most people feel fine on it. The side effects, when they happen, are usually mild stomach upset or nausea, which food helps. If you were prescribed the single dose of azithromycin instead, that's one and done in the clinic or pharmacy. For the full regimens and dosing details across infections, see our guide to chlamydia treatment.
You usually don't need a return visit to confirm the cure. Two practical things matter: get your partners treated so you don't pass it back and forth, and put the 3-month retest in your calendar before you leave the appointment.
Why your partners need treatment too
Treating yourself but not your partners leads to a 'ping-pong' loop of reinfection. Refer, test, or presumptively treat every sex partner from the prior 60 days. Both you and any treated partner should abstain from sex for 7 days after single-dose therapy, or until a 7-day course is finished, so the antibiotic can clear the infection before you have sex again.
Partner treatment measurably lowers your odds of getting reinfected. In a landmark randomized trial, handing patients medication to deliver to their partners — expedited partner therapy — cut persistent or repeat infection, with the largest benefit seen for gonorrhea (3% versus 11%) Golden et al., NEJM. Expedited partner therapy is permitted in most US states but not all, so verify your local status before relying on it. In many states you can also notify partners anonymously through the health department.
Follow-up, retesting, and test-of-cure
For non-pregnant people, a test-of-cure is generally not advised. The antibiotics work, and a NAAT can stay positive for weeks after the bacteria are dead because it detects genetic material, not live organisms. Retesting too soon can scare you for no reason.
What you do need is a retest about 3 months after treatment. It's not checking whether the cure worked; it's screening for reinfection, which is common and usually comes from an untreated or new partner. Test-of-cure is reserved for specific situations: if you couldn't take the medication as prescribed, if symptoms persist, or if reinfection is suspected.
Pregnancy is the exception. Pregnant patients should have a test-of-cure roughly 4 weeks after finishing treatment, and then a retest at 3 months, because a missed infection has consequences for the baby.
What happens if chlamydia goes untreated
Most chlamydia infections cause no symptoms, so they get missed, and untreated cases do real damage over time. The complication burden falls heaviest on women CDC About Chlamydia:
- Pelvic inflammatory disease (PID) — infection spreading into the uterus, fallopian tubes and ovaries, which can cause pain and lasting harm.
- Fallopian-tube scarring, which can block the tubes.
- Ectopic pregnancy — a pregnancy that implants outside the uterus, a medical emergency — and infertility, both consequences of that scarring.
- Chronic pelvic pain that can persist long after the infection.
In men, untreated chlamydia can cause epididymitis, inflammation of the coiled tube behind the testicle, with pain and sometimes fever, and rarely sterility. Either sex can develop reactive arthritis (formerly Reiter syndrome), joint inflammation triggered by the infection. Chlamydia also appears to increase the risk of acquiring or transmitting HIV, because inflammation in the genital tract makes it easier for the virus to cross.
Preventing reinfection going forward
Condoms used correctly every time lower your risk, and a long-term mutually monogamous relationship with a tested partner removes most of it. But because most infections are silent, the prevention that actually moves the needle is routine screening and treating partners.
DoxyPEP is a newer option for some people: a single 200 mg dose of doxycycline taken within 72 hours of sex reduces chlamydia by more than 70% CDC DoxyPEP, 2024. It's offered to men who have sex with men and transgender women who've had a bacterial STI in the past 12 months, not a general-population tool. If you want to understand how chlamydia and its frequent co-infection differ, our comparison of gonorrhea vs chlamydia breaks it down.
| Regimen | Who it's for | Dose & duration | Notes |
|---|---|---|---|
| Doxycycline (preferred) | Most non-pregnant adults | 100 mg twice daily, 7 days | Best for rectal infection; take with food, avoid strong sun |
| Azithromycin (alternative) | Non-pregnant adults; preferred in pregnancy | 1 g single dose | Convenient; less effective for rectal/male infection |
| Levofloxacin (alternative) | Non-pregnant adults | 500 mg once daily, 7 days | Used when other options aren't suitable |
| Amoxicillin (pregnancy alt.) | Pregnant patients | 500 mg three times daily, 7 days | Alternative to azithromycin in pregnancy |
When to see a clinician
See a clinician if you've tested positive, if a partner tells you they tested positive, or if you have symptoms like unusual discharge, burning with urination, or pelvic or testicular pain. Screening guidance is asymmetric: the USPSTF gives a Grade B recommendation to screen sexually active women 24 and under, but an I-statement (insufficient evidence) for screening men, because the complication burden falls on women USPSTF.
Getting tested is straightforward — a first-catch urine cup or a self-collected swab, no blood draw and no urethral swab, with results often back in one to three days. Care is free or low-cost at Planned Parenthood, health departments, and Title X clinics, at-home kits run roughly $50–150, and it's often $0 with insurance. You can get tested in minutes, compare testing providers if you're using an at-home kit, and read more on chlamydia testing & diagnosis. A common mistake is testing the morning after a hookup. A NAAT is most reliable about two weeks out, so see when to test after exposure before you draw conclusions from an early negative.