Key takeaways
- A test of cure checks whether treatment worked. A 3-month retest checks for a new infection. They're different tests with different timing.
- CDC recommends retesting about 3 months after treatment for chlamydia and gonorrhea, even if partners were treated.
- Pharyngeal (throat) gonorrhea needs a test of cure 7–14 days after treatment.
- Chlamydia NAATs shouldn't be repeated less than 4 weeks after treatment, and trichomoniasis NAATs not before 3 weeks, because leftover genetic material can cause false positives.
- CDC recommends a trichomoniasis retest about 3 months after treatment for sexually active women.
After a positive STI result and a course of antibiotics, most people want one more test to prove it's gone, and they want it right away. That instinct makes sense, but the timing matters. Testing too soon can show a "positive" from leftover genetic material of bacteria that are already dead. Waiting too long can miss a reinfection from a partner who wasn't treated.
CDC's STI Treatment Guidelines separate two kinds of follow-up testing. Knowing which one you need saves money and stress.
Two different follow-up tests
| Test of cure | Reinfection check (retest) | |
|---|---|---|
| Question it answers | Did the treatment work? | Have I been infected again since treatment? |
| When it's used | Only in specific situations (see below) | Routinely after chlamydia, gonorrhea, and (for women) trichomoniasis |
| Typical timing | Depends on the infection: 7–14 days for throat gonorrhea, about 4 weeks for chlamydia in pregnancy | About 3 months after treatment |
| Main risk of getting it wrong | Testing too early can give false positives | Skipping it can miss a reinfection from an untreated partner |
Why testing too soon can mislead
Most STI tests for chlamydia, gonorrhea, and trichomoniasis are NAATs (nucleic acid amplification tests). They're very sensitive because they detect genetic material, but they can't tell live organisms from dead ones. After successful treatment, fragments can stay detectable for a while. CDC's guidance reflects this:
- Chlamydia: CDC says using chlamydia NAATs less than 4 weeks after finishing therapy isn't recommended, because results can be positive from nonviable organisms (CDC chlamydia guidance).
- Trichomoniasis: CDC says if a NAAT is used, it shouldn't be done before 3 weeks after treatment is complete (CDC trichomoniasis guidance).
A positive result one week after treatment usually doesn't mean the antibiotics failed. More often, the test was simply too early.
Chlamydia
- Test of cure: CDC says it isn't advised for people who aren't pregnant and took a recommended or alternative regimen, unless adherence is in question, symptoms persist, or reinfection is suspected.
- Pregnancy: A test of cure about 4 weeks after finishing treatment is recommended. See STI testing during pregnancy.
- Retest: CDC says men and women should be retested about 3 months after treatment, whether or not their partners were treated.
- Abstinence: Avoid sex for 7 days after single-dose therapy, or until a 7-day course is finished and symptoms are gone.
Gonorrhea
- Genital or rectal infection: CDC says a test of cure is unnecessary after uncomplicated infection treated with a recommended or alternative regimen (CDC gonorrhea guidance).
- Throat infection: CDC says anyone with pharyngeal gonorrhea should return 7–14 days after treatment for a test of cure. Throat gonorrhea is harder to cure, so this check matters. Our throat swab vs urine guide explains why a urine test can't answer this question.
- Retest: CDC recommends retesting 3 months after treatment. If that's not possible, retest at the next medical visit within 12 months.
Trichomoniasis
- Women: CDC recommends retesting all sexually active women about 3 months after initial treatment.
- Men: CDC says there isn't enough evidence to support routine retesting of men after treatment.
- NAAT timing: Not before 3 weeks after treatment is complete.
More background is in our trichomoniasis testing guide.
Why the 3-month retest exists
Reinfection is common, usually from a partner who wasn't treated or from a new partner. The 3-month retest is designed to catch that, not to second-guess the antibiotics. That's why CDC recommends it even when you're confident your partner was treated.
Make sure partners are treated
The best way to avoid a positive retest is to make sure recent partners are tested and treated before you have sex with them again. For chlamydia, CDC says partners from the 60 days before your symptoms or diagnosis should be evaluated and treated, and your most recent partner should be treated even if it's been longer than 60 days. Some states allow expedited partner therapy, where your clinician gives you treatment to pass on to a partner. If you need help with that conversation, see what to do when a partner tests positive.
A simple retesting plan
Most people never get the 3-month retest because nobody reminds them. A little planning on the day you finish treatment fixes that:
- Write down three dates: the day you were tested, the day you finished treatment, and the day your partners were treated (if you know it).
- Set a reminder for 3 months after treatment. If you were treated for throat gonorrhea, set a second reminder for 7–14 days after treatment for the test of cure.
- Test the same body sites. If the infection was rectal or in the throat, a urine-only kit won't check that site.
- Use the same type of test if you can. A NAAT retest is easiest to compare with a NAAT diagnosis.
- Keep your results. If the retest is positive, your clinician will want to know which regimen you took and when.
If you have new partners before your 3-month retest, the retest also works as routine screening. You may want to add other tests at the same time based on your exposures.
When to contact a clinician sooner
Don't wait for the 3-month mark if:
- Symptoms continue or come back after you finish treatment.
- You develop pelvic pain, testicular pain, fever, or pain during sex.
- You missed doses or vomited soon after a single-dose pill.
- You had throat gonorrhea and haven't had a test of cure.
Persistent symptoms with negative tests can have other causes. Negative test but still have symptoms covers what to ask next.
Retesting at the 3-month mark?
Collect a retest sample at home with myLAB Box
If your clinician has confirmed you're due for a routine 3-month recheck, myLAB Box sells at-home collection kits that you mail to a lab. Choose a kit that covers the body sites that were infected. A throat test of cure after gonorrhea is better arranged through your clinician.
Shop myLAB Box →The bottom line
For most people treated for chlamydia or gonorrhea, the right follow-up is a retest about 3 months later, not a test the following week. The main exceptions are throat gonorrhea (test of cure at 7–14 days) and chlamydia during pregnancy (test of cure at about 4 weeks). Women treated for trichomoniasis should also retest at about 3 months. Put the date in your calendar when you finish your medication.
Frequently asked questions
How soon after chlamydia treatment can I retest?
CDC says chlamydia NAATs shouldn't be used less than 4 weeks after finishing treatment, because they can detect dead organisms. The routine recommendation is a retest about 3 months after treatment.
Do I need a test of cure after gonorrhea?
Only for throat (pharyngeal) gonorrhea, which CDC says should be retested 7–14 days after treatment. For uncomplicated genital or rectal gonorrhea treated with a recommended regimen, a test of cure isn't needed. Everyone should retest at about 3 months.
Why retest at 3 months if the antibiotics worked?
The 3-month retest checks for reinfection, which is common, often from a partner who wasn't treated. It's recommended even if your partners were treated.
I tested positive again a week after treatment. Did the treatment fail?
Not necessarily. NAATs can stay positive for a while after a cure. Talk with your clinician, who can consider timing, symptoms, adherence, and possible re-exposure.
Should men retest after trichomoniasis?
CDC says data are insufficient to support routine retesting of men after treatment. Women should retest about 3 months after treatment.
Sources
- CDC STI Treatment Guidelines: Chlamydial Infections
- CDC STI Treatment Guidelines: Gonococcal Infections Among Adolescents and Adults
- CDC STI Treatment Guidelines: Trichomoniasis
- CDC: Legal Status of Expedited Partner Therapy
Guidance changes. When timing or treatment matters, check the current linked guidance or ask a clinician.
Disclaimer: This article is for informational purposes only and does not diagnose, prescribe, or replace individualized medical care. Testing and treatment decisions should be made with a qualified healthcare provider. Some links on this page are affiliate links; we may earn a commission at no extra cost to you.