H. pylori is treated with a combination of antibiotics and an acid-suppressing medication, taken together for 10 to 14 days. The current recommended first-line approach is bismuth quadruple therapy, which uses four medications simultaneously to kill the bacteria. With proper adherence, this regimen clears the infection in roughly 90% of cases.
Why Treatment Requires Multiple Drugs
H. pylori lives in the acidic environment of your stomach lining, which makes it unusually difficult for a single antibiotic to reach and kill. The acid-suppressing medication in every treatment regimen raises the pH inside your stomach, creating conditions where antibiotics work more effectively. Without that acid reduction, antibiotics like amoxicillin and clarithromycin break down too quickly to do their job.
Using multiple antibiotics at once also reduces the chance that resistant bacteria survive. Antibiotic resistance in H. pylori has become a serious global problem. Clarithromycin resistance now exceeds 15% in the majority of countries studied, ranging from 12% to over 90% depending on the region. This is the main reason treatment guidelines have shifted away from older, simpler regimens toward more aggressive combinations.
The Recommended First-Line Regimen
The American College of Gastroenterology now recommends optimized bismuth quadruple therapy as the go-to treatment for patients who have never been treated before. This regimen includes four components taken for 14 days:
- An acid-suppressing medication (PPI), taken twice daily
- Bismuth (the active ingredient in Pepto-Bismol), taken four times daily
- Tetracycline, an antibiotic taken four times daily
- Metronidazole, an antibiotic taken three or four times daily
The pill burden is high. You’ll be taking multiple doses of four different medications every day, which means a lot of pills to keep track of. But the regimen works: bismuth quadruple therapy achieves eradication rates around 90%, compared to roughly 75% for older standard therapies. The bismuth component has a direct antimicrobial effect on H. pylori and also forms a protective coating on the stomach lining.
Older triple therapy regimens that used clarithromycin as their primary antibiotic are no longer recommended as a first choice in most countries. Because clarithromycin resistance is so widespread, these regimens fail too often when prescribed without knowing whether the specific strain is susceptible.
Does Treatment Duration Matter?
Most guidelines recommend 14 days, but recent evidence suggests 10 days may work nearly as well. A randomized trial of over 300 patients found that 10-day and 14-day bismuth quadruple therapy produced almost identical eradication rates: 92.4% versus 92.9%. Among patients who completed the full course, the rates climbed to 97.9% and 99.3%, respectively.
The 10-day group also experienced significantly less dizziness (18.5% versus 34%) and vomiting (4.5% versus 12.8%). Overall side effect rates were similar between the two groups, but the shorter course caused fewer of the more disruptive symptoms. Your doctor may still prescribe 14 days based on current guideline language, but this is an area where practice is evolving.
Common Side Effects
About 23% of people experience at least one side effect during treatment. The most frequent are taste disturbance (often a metallic taste), diarrhea, nausea, and abdominal pain. The majority of these are mild, and the average duration is about seven days. Bismuth-based regimens tend to have the highest side effect rates, around 33% to 37%, largely because of the number of medications involved.
Despite those numbers, very few people stop treatment early. In large studies, only 1.3% of patients discontinued therapy because of side effects, and overall compliance was 97%. Finishing the full course matters enormously. Alongside antibiotic resistance, adherence is the single most important factor in whether treatment succeeds. Stopping early, skipping doses, or cutting the course short gives surviving bacteria a chance to repopulate and potentially develop resistance.
Probiotics can help manage antibiotic-related diarrhea and support your gut bacteria during treatment. They won’t treat H. pylori on their own, but they can make the two weeks more tolerable. Avoiding spicy foods, alcohol, and highly acidic foods during treatment can also reduce stomach irritation, since your stomach lining is already under stress from both the infection and the medications.
What Happens If Treatment Fails
If the first round doesn’t clear the infection, your doctor will typically recommend a different antibiotic combination for the second attempt. At this point, antibiotic susceptibility testing becomes important. Rather than guessing which antibiotics will work, a lab can test your specific H. pylori strain to identify which drugs it’s resistant to.
Amoxicillin remains one of the most reliable options globally, with resistance rates under 2% in most countries. Levofloxacin is sometimes used in second-line regimens, but resistance to it is also climbing, reaching over 40% in North America and as high as 65% in parts of Africa and Asia. This is why targeted testing after a failed first attempt leads to better outcomes than simply trying another empiric regimen.
Confirming the Infection Is Gone
After finishing treatment, you’ll need a follow-up test to confirm the bacteria have been eradicated. This is typically a breath test or a stool antigen test. You need to wait at least four weeks after completing antibiotics before testing, because earlier testing can produce inaccurate results.
If your treatment included bismuth or if you’re still taking an acid-suppressing medication, you may need to stop those at least two weeks before the follow-up test as well. Both can interfere with test accuracy. Your doctor will give you specific timing instructions, but the key point is that skipping the confirmation test is a mistake. Without it, you won’t know whether the infection is truly gone or quietly persisting.