Four common sexually transmitted infections are fully curable with the right treatment: chlamydia, gonorrhea, syphilis, and trichomoniasis. All four are caused by bacteria or parasites, which antibiotics can eliminate from your body. Viral STIs like herpes, HIV, and HPV cannot be cured, though they can be managed or, in the case of HPV, often cleared naturally by the immune system.
The Four Curable STIs
The dividing line between curable and non-curable STIs comes down to what’s causing the infection. Bacteria and parasites can be killed with medication. Viruses, on the other hand, integrate into your cells or hide in ways that current drugs can’t fully reach. Here’s what you need to know about each curable infection.
Chlamydia
Chlamydia is the most commonly reported bacterial STI and one of the easiest to cure. A standard course of oral antibiotics taken twice daily for seven days clears the infection. In clinical trials, this regimen achieved a 100% cure rate for rectal chlamydia infections, compared to 74% for an older single-dose alternative. Most people finish treatment and are completely free of the bacteria within a week or two.
The catch is that chlamydia often causes no symptoms at all, especially in women. Left untreated, it can spread to the uterus and fallopian tubes, causing pelvic inflammatory disease, chronic pain, and infertility. That’s why routine screening matters even when you feel fine.
Gonorrhea
Gonorrhea is curable, but treating it has become more complicated over the years. The bacteria responsible has developed resistance to nearly every antibiotic ever used against it, leaving only one recommended class of drugs that still works reliably. Treatment is now a single injection rather than a pill. So far, no verified treatment failures with this approach have been reported in the United States, but the narrowing of options is a real concern in public health.
Like chlamydia, untreated gonorrhea can cause pelvic inflammatory disease and infertility in women. It can also spread to the blood and joints, causing a serious systemic infection. Symptoms sometimes include painful urination and discharge, but many infections are silent.
Syphilis
Syphilis is cured with a single injection of penicillin for early-stage infections. It’s one of the oldest known treatments still in use, and it remains highly effective. If syphilis has progressed to a later stage, you may need weekly injections over three weeks instead.
Syphilis progresses through distinct stages. The first sign is typically a painless sore at the site of infection, which heals on its own even without treatment. That self-healing is deceptive, because the bacteria remain in your body and can eventually affect the brain, heart, and other organs if left untreated for years. Early treatment prevents all of that.
Trichomoniasis
Trichomoniasis is caused by a parasite rather than bacteria, but it’s still curable with oral medication. Cure rates in clinical trials range from 84% to 98% with one standard drug and 92% to 100% with an alternative. If the first round doesn’t fully clear the infection, a second course typically does.
Trichomoniasis is extremely common and frequently goes undiagnosed because symptoms can be mild or absent, particularly in men. Women are more likely to notice symptoms like unusual discharge, itching, or discomfort during urination. Untreated trichomoniasis can increase susceptibility to other STIs, including HIV.
Viral STIs: Manageable but Not Curable
Herpes (HSV), HIV, and human papillomavirus (HPV) are all caused by viruses and cannot be fully eliminated from the body with current medicine. That said, “not curable” doesn’t mean “not treatable,” and the outlook varies significantly between them.
Genital herpes is a lifelong infection. Antiviral medications can reduce the frequency and severity of outbreaks and lower the risk of transmitting the virus to a partner. However, these drugs don’t eradicate the virus. It remains dormant in nerve cells, and outbreaks can return after medication is stopped. Many people with herpes have infrequent or mild outbreaks that become less bothersome over time.
HIV is managed with daily antiviral therapy that suppresses the virus to undetectable levels. People on effective treatment can live a normal lifespan and cannot transmit HIV sexually. But the virus persists in hidden reservoirs in the body, so stopping treatment allows it to rebound.
HPV is a unique case. About 90% of HPV infections clear on their own within two years as the immune system suppresses the virus. There’s no antiviral drug for HPV itself, but the health problems it can cause, like genital warts and precancerous cell changes, are treatable. Vaccination before exposure prevents the most dangerous strains entirely.
Why “Cured” Doesn’t Mean “Protected”
One important thing to understand about curable STIs: getting treated once doesn’t give you any immunity. You can be reinfected the next time you’re exposed, and reinfection is common. This is especially true if your sexual partner wasn’t treated at the same time you were. The CDC recommends that anyone diagnosed with chlamydia, gonorrhea, or trichomoniasis get retested three months after treatment to check for repeat infection.
Partner treatment is a critical part of the process. If only one person takes antibiotics, the untreated partner can pass the same infection right back. In many states, your doctor can prescribe medication for your partner without requiring a separate office visit, specifically to break this cycle of reinfection.
What Happens If You Skip Treatment
All four curable STIs can cause serious long-term damage when left untreated. Chlamydia and gonorrhea are major causes of pelvic inflammatory disease in women, which can lead to chronic pelvic pain, ectopic pregnancy, and permanent infertility. These complications develop silently in many cases, because the underlying infection never produced noticeable symptoms.
Untreated syphilis follows a slow but destructive path. After the initial sore heals, the bacteria can quietly damage the cardiovascular system, nervous system, and brain over a period of years to decades. Untreated trichomoniasis, while less likely to cause organ damage, creates inflammation that makes it easier for other infections, including HIV, to take hold.
Any untreated STI also increases the risk of transmitting or acquiring HIV. The inflammation and tissue disruption caused by an active infection creates more entry points for the virus. Treating curable STIs promptly is one of the most effective ways to reduce that risk.
Getting Tested and Treated
Because so many STIs produce no symptoms, testing is the only reliable way to know your status. Standard STI panels typically screen for chlamydia, gonorrhea, syphilis, and HIV. Trichomoniasis testing is often available but may not be included automatically, so it’s worth requesting if you have symptoms or risk factors. Herpes testing is generally not part of routine screening unless you have active sores.
If you test positive for a curable STI, treatment is straightforward and usually takes no more than a week or two. You should avoid sexual contact until treatment is complete and, for some infections, until a follow-up test confirms the infection has cleared. The sooner you’re treated, the lower the risk of complications or passing the infection to someone else.