H. pylori treatment requires a combination of antibiotics and an acid-reducing medication, taken together for 10 to 14 days. There is no single pill that clears this infection. The standard approach uses three or four medications simultaneously, and finishing the entire course is critical for success. Here’s what treatment looks like, what to expect while you’re on it, and how to confirm the infection is gone.
What First-Line Treatment Looks Like
The most widely recommended first-line option is called bismuth quadruple therapy. It combines four medications: a proton pump inhibitor (an acid-reducing pill) taken twice daily, tetracycline four times daily, metronidazole three or four times daily, and a bismuth compound (the active ingredient in Pepto-Bismol) four times daily. That’s a lot of pills spread throughout the day, which is one of the biggest challenges of treatment.
Your doctor may instead prescribe a different combination depending on what’s available and what antibiotics you’ve taken before. Some regimens use amoxicillin or clarithromycin in place of tetracycline and metronidazole. But rising antibiotic resistance has pushed bismuth quadruple therapy to the front of the line in many regions, because the bacteria are less likely to resist the drugs in that combination.
The acid-reducing medication isn’t just for comfort. H. pylori thrives in acidic environments, and lowering stomach acid makes the antibiotics more effective at killing the bacteria. Skipping this component significantly reduces your chances of clearing the infection.
How Long You Need to Take It
Most guidelines recommend 14 days. However, a 2024 randomized trial published in eClinicalMedicine compared 10-day and 14-day courses of bismuth quadruple therapy in over 300 patients and found nearly identical eradication rates: 92.4% for the shorter course versus 92.9% for the longer one. In patients who completed their full regimen, success rates climbed above 97% in both groups.
The 10-day group did report less dizziness (18.5% vs. 34%) and less vomiting (4.5% vs. 12.8%). So if side effects are making the regimen hard to tolerate, it’s worth discussing a 10-day course with your doctor rather than quitting early. Stopping antibiotics before completing the course is one of the main reasons treatment fails and resistance develops.
Side Effects During Treatment
Expect side effects. In clinical trials, more than half of patients on bismuth quadruple therapy reported at least one. The most common include nausea, dizziness, a metallic taste in the mouth, darkened stools (from the bismuth), diarrhea, and headache. These are uncomfortable but not dangerous, and they resolve after treatment ends.
Adding a probiotic supplement during treatment can meaningfully reduce these symptoms. A 2025 study in Frontiers in Pharmacology found that patients who took probiotics containing Lactobacillus and Bifidobacterium strains alongside their antibiotics had half the rate of gastrointestinal side effects compared to those who didn’t (15% vs. 30%). Antibiotic-associated diarrhea dropped from 18.3% to 7.5%, and bloating fell from 22.5% to 12.5%. The probiotic group also had better adherence: 91.7% completed their full course, compared to 83.3% without probiotics. Look for a product with at least 1 billion CFU per day of Lactobacillus or Bifidobacterium species.
Food, Alcohol, and Timing Rules
The medications in this regimen have specific and important interactions with food and drink. Getting the timing wrong can reduce how much antibiotic your body absorbs, which lowers your chance of clearing the infection.
Tetracycline and dairy don’t mix. Calcium in dairy products binds to tetracycline and prevents your body from absorbing it. Take tetracycline one hour before or two hours after meals. Wash it down with a full glass of water while sitting or standing upright, because it can cause irritation or ulceration in the esophagus if it gets stuck on the way down. Don’t lie down right after taking it.
Bismuth should be taken after meals. The standard recommendation is to take the bismuth compound after breakfast, lunch, and dinner, with a fourth dose at bedtime (preferably with a small snack). This can feel contradictory since tetracycline needs to be taken away from food. Your pharmacist can help you map out a daily schedule that spaces everything correctly.
No alcohol during treatment, and for three days after. Metronidazole reacts with alcohol in a way that can cause intense flushing, throbbing headache, nausea, vomiting, rapid heartbeat, and drops in blood pressure. This isn’t a mild interaction. It applies to alcoholic beverages and also to products containing alcohol, including some mouthwashes and cooking wines. Avoid all alcohol during treatment and for at least three full days after your last dose of metronidazole.
What Happens If First Treatment Fails
About 5 to 15% of people don’t clear the infection on the first attempt. Antibiotic resistance is the main reason. Resistance to clarithromycin and metronidazole has been climbing steadily. Data from a recent five-year study showed resistance rates above 75% for both drugs in populations with prior treatment failure, and dual resistance to both reached over 60%.
If your first round doesn’t work, your doctor will typically switch to a different antibiotic combination. Second-line options include regimens using levofloxacin in place of one of the original antibiotics. For patients who have failed multiple treatments, a rifabutin-based regimen is available as a rescue option. Tetracycline and a less commonly used antibiotic called furazolidone have maintained near-complete effectiveness even in resistant populations, which is why they remain reliable building blocks for retreatment.
After a first treatment failure, some guidelines recommend susceptibility testing, where a sample of your H. pylori is tested in a lab to determine exactly which antibiotics it responds to. This allows your doctor to choose a tailored regimen instead of guessing, which significantly improves the odds of clearing it on the second try.
Confirming the Infection Is Gone
You need a follow-up test to confirm eradication. Don’t assume treatment worked just because your symptoms improved. H. pylori can persist at low levels without causing noticeable symptoms, and untreated infection raises long-term risks for ulcers and stomach cancer.
The standard confirmation method is a urea breath test or a stool antigen test. Both are noninvasive. The key detail is timing: you need to wait at least four weeks after finishing your antibiotics before testing. If you’re still taking a proton pump inhibitor or bismuth, you’ll need to stop those at least two weeks before the test. Both medications can suppress H. pylori enough to produce a false negative, making it look like the infection is gone when it isn’t.
If the follow-up test comes back positive, your doctor will start a second-line regimen using different antibiotics. Most people clear the infection within one or two treatment courses.