Most sexually active adults should get tested for STIs at least once a year, but the right schedule depends on your age, sex, number of partners, and the specific infection. Some people need testing every three months; others may only need a one-time screen. Here’s how to figure out what applies to you.
The Baseline: At Least Once a Year
If you’re sexually active with more than one partner or aren’t in a long-term mutually monogamous relationship, annual testing for common STIs is the starting point. That typically includes chlamydia, gonorrhea, syphilis, and HIV. The CDC recommends every adult between 13 and 64 get tested for HIV at least once in their lifetime as part of routine health care, even without specific risk factors. People with ongoing risk factors should be screened for HIV at least annually.
Hepatitis C follows a similar one-time-minimum approach. All adults 18 and older should be screened at least once. If you inject drugs or receive ongoing hemodialysis, periodic retesting is recommended.
Women Under 25
Sexually active women under 25 should be screened for chlamydia and gonorrhea every year, regardless of other risk factors. These two infections are especially common in this age group and often cause no symptoms at all. Left untreated, they can lead to pelvic inflammatory disease and fertility problems.
Women 25 and older don’t automatically need annual chlamydia and gonorrhea screening, but they do if any of these apply: a new partner, more than one partner, a partner who has other partners, inconsistent condom use outside a monogamous relationship, a previous STI, or a history of exchanging sex for money or drugs.
Men Who Have Sex With Men
Guidelines are more aggressive here because STI transmission rates are significantly higher in this group. Men who have sex with men should be tested for syphilis, chlamydia, and gonorrhea at least once a year, and every three to six months if they have multiple partners. Testing should cover all relevant sites: urine, rectal, and oral swabs, since infections at the throat or rectum often produce no symptoms and would be missed by a urine-only test.
If You’re on PrEP
Taking PrEP comes with a built-in testing schedule that’s more frequent than most people realize. On oral PrEP, you’ll need an HIV test at least every three months to confirm the medication is still being used preventively rather than masking an active infection. STI screening for syphilis and gonorrhea is recommended at least every six months for all PrEP users. Men who have sex with men and transgender women on PrEP should be screened for bacterial STIs including chlamydia every three to six months depending on risk history. Heterosexually active people on PrEP should be screened for chlamydia at least once a year.
Injectable PrEP follows a slightly different cadence. HIV testing starts at month three and repeats at least every two months. Bacterial STI screening for men who have sex with men begins at month three and repeats every four months. For heterosexually active people, bacterial STI screening starts at month seven and repeats every six months.
During Pregnancy
All pregnant people should be screened for HIV, syphilis, and hepatitis B at the first prenatal visit. Chlamydia and gonorrhea screening is recommended for pregnant people under 25 and for those 25 and older with risk factors. Retesting in the third trimester is recommended for people at elevated risk, because an infection acquired during pregnancy can cause serious complications for the baby, including preterm birth and congenital syphilis.
After a Specific Exposure
If you had unprotected sex with a new partner or think you were exposed to an STI, don’t rush to the clinic the next morning. Tests need time to detect an infection, and testing too early can produce a false negative. Each STI has its own “window period,” the time between exposure and when a test can reliably pick it up.
- Chlamydia and gonorrhea: One week catches most infections. Two weeks catches nearly all.
- Syphilis: A blood test picks up most cases at one month. Three months catches nearly all.
- HIV (blood test, antigen/antibody method): Two weeks detects most infections. Six weeks catches nearly all.
- HIV (oral swab): One month detects most. Three months catches nearly all.
If you’re concerned about a specific exposure, a practical approach is to test at two weeks for chlamydia and gonorrhea, then again at six weeks for HIV (blood draw), and at three months for syphilis and to confirm the HIV result. That two-step approach balances early detection with accuracy.
Why Routine Testing Matters Even Without Symptoms
Most STIs don’t produce obvious symptoms, especially in the early stages. Chlamydia is often called a “silent” infection because the majority of people who have it feel completely fine. Gonorrhea can infect the throat or rectum without any noticeable signs. Syphilis has an early painless sore that many people never notice, followed by a latent phase that can last years. HIV may cause a brief flu-like illness within a few weeks of infection, then nothing for years.
The practical consequence is straightforward: you can’t rely on how you feel to know your status. Screening catches infections when they’re easily treatable and before they’re passed to someone else. For bacterial infections like chlamydia, gonorrhea, and syphilis, treatment is a short course of antibiotics. Catching HIV early means starting treatment sooner, which keeps viral levels undetectable and prevents transmission to partners.
How to Figure Out Your Schedule
Your testing frequency comes down to a few key questions: How many partners have you had in the past year? Are your partners also having sex with other people? Are you using condoms consistently? Have you been diagnosed with an STI before? Do you use injectable drugs?
If you’re in a long-term monogamous relationship where both partners tested negative at the start, routine retesting isn’t necessary unless something changes. If you have one or two new partners a year and use condoms consistently, annual testing is reasonable. If you have multiple partners, inconsistent condom use, or partners whose status you don’t know, every three to six months is more appropriate. And if you’re on PrEP, follow the schedule your prescriber sets, since it’s designed to catch infections before they become harder to manage.