Antibiotics cure bacterial and parasitic STIs — chlamydia, gonorrhea, syphilis, and trichomoniasis — by killing the organism outright. Antivirals can't cure viral STIs like herpes, HIV, hepatitis B, or HPV; they suppress the virus and control symptoms instead. The dividing line is simple: bacterial means curable, viral means manageable for life CDC 2021 Guidelines.
antibiotics clear them
medicine controls, doesn't cure
| Item | Value |
|---|---|
| Bacterial & parasitic (chlamydia, gonorrhea, syphilis, trich) | curable — antibiotics clear them |
| Viral (herpes, HIV, hepatitis B, HPV) | managed — medicine controls, doesn't cure |
What antibiotics and antivirals actually are
Antibiotics are drugs that attack bacteria — they break down the cell wall, jam the machinery a bacterium uses to build proteins, or stop it from copying its DNA. Because parasites like the trichomonas organism share enough biology, certain antiparasitic antibiotics work on them too. Once the bug is dead, the infection is gone; that's what "cure" means here.
Antivirals work on a different enemy. Viruses hijack your own cells to reproduce, so there's no separate organism to simply kill off. Antivirals slow or block the virus from copying itself, which keeps the amount of virus in your body low and your symptoms quiet. They don't clear the virus from where it hides — herpes settles into nerve roots, HIV integrates into immune cells — so the medicine controls the infection rather than ending it.
The key differences
What "cure" means with antibiotics
For a bacterial or parasitic STI, finishing the right antibiotic eliminates the infection. Chlamydia, gonorrhea, syphilis, and trichomoniasis all fall here. Treatment is usually a short course of pills or a single shot, and most people feel better within a few days. But feeling better is not proof of cure — some infections call for a follow-up test-of-cure or a retest weeks to months later to confirm the bug is truly gone and you weren't reinfected.
What "control" means with antivirals
For a viral STI, the goal shifts from elimination to management. Antivirals reduce outbreaks (herpes), keep the virus undetectable and the immune system intact (HIV), or limit liver damage (hepatitis B). HPV often clears on its own through your immune system, and the precancerous changes it can cause are treated directly, but no drug "cures" the virus itself. You stay on therapy long-term, and you can still live a full, healthy life — it's a chronic condition you control, not a one-and-done.
Why taking the right drug matters
Matching the drug to the cause isn't optional. Antibiotics do nothing against a virus like herpes or HIV — taking them anyway won't help and feeds antibiotic resistance, where bacteria evolve to survive the drugs meant to kill them. Gonorrhea is the warning shot: it has grown resistant to nearly every antibiotic once used against it CDC, Drug-Resistant Gonorrhea. That's why the only recommended treatment now is a single ceftriaxone injection, and why getting the right drug at the right dose matters for keeping it treatable at all.
Side-by-side comparison
| Antibiotics | Antivirals | |
|---|---|---|
| Target | Bacteria and parasites | Viruses |
| Outcome | Cure — infection eliminated | Control — virus suppressed, not cleared |
| STIs treated | Chlamydia, gonorrhea, syphilis, trichomoniasis | Herpes, HIV, hepatitis B, HPV |
| Typical course | Short course of pills or a single shot | Ongoing or long-term medicine |
| After treatment | May need a test-of-cure or retest | Stay on therapy; monitor over time |
| Common side effects | Stomach upset, sun sensitivity, injection soreness | Vary by drug; generally well tolerated |
Which one applies to you
You don't choose between antibiotics and antivirals — your diagnosis does. The deciding factor is what the test finds. A bacterial result (chlamydia, gonorrhea, syphilis) or a parasitic one (trichomoniasis) points to antibiotics and a curable path. A viral result (herpes, HIV, hepatitis B, HPV) points to antiviral management. That's why an accurate diagnosis comes first — there is no over-the-counter product or home remedy that cures any STI. Yogurt, garlic, douching, and detoxes do nothing; you need the specific prescription medicine matched to a real result.
A few specifics on the curable side. Chlamydia is commonly treated with doxycycline, which can cause stomach upset and sun sensitivity — take it with food and stay out of strong sun. Trichomoniasis and bacterial vaginosis are treated with metronidazole or tinidazole, which react badly with alcohol, so skip alcohol during treatment and for a short time afterward CDC, Trichomoniasis Treatment. Gonorrhea is the single ceftriaxone injection, where soreness at the injection site is the main complaint. For the full picture on managing these reactions, see our guide to std antibiotic side effects and what to expect.
The practical next step
Treatment in real life is more accessible than people expect. It's usually a short course of pills or a single shot, often free or low-cost at a health department or Planned Parenthood. Many clinics can treat your partners without their own visit through expedited partner therapy, where you're given medicine or a prescription to pass along — that closes the loop that lets infections bounce back.
If you can be reinfected, the work isn't done when your symptoms fade. Two rules protect the result:
- Take the full course exactly as prescribed and make sure partners are treated too — stopping early or skipping a partner is the single most common way an infection quietly persists or comes straight back.
- Avoid sex until you and your partners have finished treatment and any wait period your clinician gives — often a week after a single-dose treatment — so you don't pass it back and forth.
If you haven't been diagnosed yet, that's step one. You can get tested confidentially, and if you're testing after a recent encounter, check when to test after exposure so you don't test too early and trust a false negative. For gonorrhea specifically, the lab method matters for an accurate result — here's how a gonorrhea test works.
When to talk to a clinician
See a clinician any time you have symptoms — discharge, sores, burning with urination, unusual bleeding — or a known exposure, even if you feel fine. Don't self-treat with leftover antibiotics or anything you bought without a diagnosis; the wrong drug wastes time, can worsen resistance, and leaves an untreated infection to do damage. If symptoms don't improve after finishing treatment, or return weeks later, go back — that can signal reinfection or, with gonorrhea, a resistance problem that needs different management.