Four common STIs are curable with antibiotics or antiparasitic medication: chlamydia, gonorrhea, syphilis, and trichomoniasis. The first three are bacterial infections, and trichomoniasis is caused by a parasite. All four can typically be eliminated with a single course of treatment. The remaining major STIs, including HIV, herpes, hepatitis B, and HPV, are caused by viruses and cannot be cured, though they can be managed or, in the case of HPV, often cleared naturally by the immune system.
Chlamydia
Chlamydia is the most commonly reported bacterial STI and one of the simplest to cure. Treatment is a seven-day course of oral antibiotics. Many people with chlamydia have no symptoms at all, which is why routine screening matters. Left untreated, it can cause pelvic inflammatory disease in women and fertility problems in both sexes. After treatment, the infection is completely gone, but you can be reinfected through future unprotected contact.
Testing is reliable as early as one week after exposure, with two weeks catching nearly all infections. A urine sample or swab is all that’s needed.
Gonorrhea
Gonorrhea is cured with a single injection of an antibiotic. Like chlamydia, it can infect the genitals, rectum, and throat, and it often produces no obvious symptoms. The testing window is similar: one week catches most cases, two weeks catches almost all.
Gonorrhea does come with a serious caveat. The bacteria that cause it have developed increasing resistance to the antibiotics used to treat it. Between 2022 and 2024, resistance to the primary treatment antibiotic rose from 0.8% to 5% globally, according to WHO surveillance data. Resistance to a related backup antibiotic jumped from 1.7% to 11% over the same period. For now, first-line treatment still works for the vast majority of cases, but rising resistance means follow-up testing after treatment is increasingly important to confirm the infection is actually gone.
Syphilis
Syphilis is cured with a single injection of penicillin when caught in its early stages (primary, secondary, or early latent). It progresses through distinct phases: a painless sore at the site of infection, then a body rash, then a long dormant period that can last years. If left untreated through all these stages, late-stage syphilis can damage the brain, heart, and other organs.
Blood testing for syphilis picks up most infections about one month after exposure, with three months catching nearly all cases. Because early syphilis sores are painless and can appear in hard-to-see locations, many people miss them entirely, making testing the most reliable way to catch it.
Trichomoniasis
Trichomoniasis is caused by a microscopic parasite rather than bacteria, but it’s still fully curable with a single dose of oral antiparasitic medication. It’s extremely common, especially in women, and symptoms can include itching, burning, or unusual discharge. Many infected people, particularly men, have no symptoms at all.
A vaginal swab catches most infections within one week, though waiting a month after exposure gives the most reliable result. Reinfection is common if sexual partners aren’t treated at the same time.
Other Curable Parasitic Infections
Pubic lice and scabies are also sexually transmitted and fully curable. Pubic lice are treated with over-the-counter lotions or mousses containing permethrin. Scabies requires a prescription topical cream. Both are eliminated within one to two treatment cycles. There’s no blood test or screening for these; diagnosis is based on visible symptoms like itching and, in the case of lice, spotting the insects or their eggs.
Viral STIs That Can’t Be Cured
The four major viral STIs, HIV, herpes (HSV), hepatitis B, and HPV, have no cure. What “incurable” means in practice, though, varies significantly from one virus to another.
HIV is managed with daily antiretroviral medication that suppresses the virus to undetectable levels. At that point, the virus can’t be transmitted sexually, and people with HIV live normal lifespans. But the virus remains in the body, and stopping medication allows it to rebound. Blood testing catches most HIV infections within two weeks to one month, depending on the test type.
Herpes (HSV-2 and HSV-1 genital infections) causes recurring outbreaks of painful sores, though many people have mild or infrequent episodes. Daily antiviral medication reduces the frequency of outbreaks and lowers transmission risk, but doesn’t eliminate the virus. Even with suppressive medication, the virus still sheds asymptomatically on a small percentage of days, meaning transmission remains possible at low levels. Blood testing for herpes antibodies catches most infections at about one month, with four months needed to detect nearly all.
HPV is the most nuanced case. While there’s no treatment that eliminates the virus itself, roughly 80% of HPV infections clear on their own within two years as the immune system suppresses the virus. The remaining 20% can persist and, depending on the HPV strain, potentially lead to genital warts or cervical and other cancers. Vaccination prevents infection with the highest-risk strains and is most effective when given before sexual activity begins. Cervical screening (Pap smears) can detect HPV-related cell changes starting a few weeks to months after infection.
Hepatitis B can become a chronic lifelong infection in about 5% of adults who contract it, though most adults clear the virus on their own. A highly effective vaccine prevents hepatitis B entirely. Blood testing picks up infection at roughly three to six weeks after exposure.
Why Reinfection Matters for Curable STIs
Curing an STI doesn’t give you immunity to it. You can catch the same infection again from an untreated partner or a new partner. This is one of the most common reasons people test positive for the same STI multiple times.
To break the cycle, treating sexual partners at the same time is critical. For chlamydia and gonorrhea, many clinicians offer what’s called expedited partner therapy: giving the diagnosed patient a prescription or medication to pass directly to their partner, so the partner can be treated without a separate clinic visit. This approach is especially useful when a partner might not seek care on their own, and it significantly reduces reinfection rates.
Testing Timelines at a Glance
- Chlamydia and gonorrhea: 1 week for most cases, 2 weeks for nearly all
- Trichomoniasis: 1 week for most, 1 month for nearly all
- Syphilis: 1 month for most, 3 months for nearly all
- HIV (blood test): 2 weeks for most, 6 weeks for nearly all
- Herpes: 1 month for most, 4 months for nearly all
- Hepatitis B: 3 to 6 weeks
- Hepatitis C: 2 months for most, 6 months for nearly all
Testing too early after exposure can produce a false negative. If you had a recent exposure and your first test comes back negative, retesting at the outer end of the window gives you the most reliable answer.