If you’re taking over-the-counter Prilosec (omeprazole), the standard course is 14 days. That’s the duration printed on the FDA-approved label for the OTC 20 mg tablet. Prescription Prilosec follows different timelines depending on the condition being treated, ranging from one week to several months, and in some cases, indefinitely.
The 14-Day Rule for OTC Prilosec
Over-the-counter Prilosec is designed as a short course: one pill per day, taken before eating, for 14 consecutive days. It’s meant for frequent heartburn (two or more days per week), not for occasional episodes. You should not restart a 14-day course without waiting at least four months, and you shouldn’t use it for more than three 14-day courses in a single year without medical guidance.
This matters because Prilosec works by shutting down acid pumps in your stomach lining. It takes a few days to reach full effect, and the 14-day window gives those pumps time to be suppressed and your esophagus time to recover. Taking it longer than directed on your own raises the chance of side effects without a clear benefit.
Prescription Timelines by Condition
When a doctor prescribes omeprazole, the length of treatment depends entirely on what’s being treated.
GERD without esophagus damage: The typical starting course is 20 mg once daily. Some people need more than eight weeks if symptoms are stubborn or the condition is chronic.
Erosive esophagitis (where stomach acid has visibly damaged the lining of the esophagus): Treatment runs four to eight weeks at 20 mg daily. Most people heal within that window.
Duodenal ulcers (ulcers in the upper part of the small intestine): Most heal within two weeks. If they don’t, a second two-week course usually finishes the job. Stubborn cases may need up to four weeks at a higher dose.
Gastric ulcers (ulcers in the stomach itself): These take longer. Most heal within four weeks, with resistant cases needing up to eight weeks.
H. pylori infection: When an ulcer is caused by a bacterial infection, omeprazole is combined with two antibiotics for one week. This “triple therapy” is a short, intensive course aimed at killing the bacteria, after which the omeprazole may continue alone to let the ulcer finish healing.
When Long-Term Use Is Appropriate
Some people genuinely need to stay on omeprazole for months or years. Barrett’s esophagus, a condition where chronic acid exposure changes the cells lining the esophagus, often requires ongoing acid suppression. Severe GERD that returns every time medication stops may also warrant long-term use. In these cases, a doctor will periodically reassess whether the dose can be lowered or the drug discontinued.
The key distinction is between self-directed long-term use (risky) and medically supervised long-term use (sometimes necessary). If you’ve been refilling OTC Prilosec on your own for months, that’s worth a conversation with your doctor, even if your symptoms feel controlled.
Risks of Taking It Too Long
The longer you take omeprazole, the more certain risks accumulate. These aren’t dramatic or immediate, which is part of the problem. They develop quietly.
Kidney damage: Research from Washington University School of Medicine found that prolonged use can erode kidney function gradually, even in people who never show obvious signs of kidney trouble. More than half of the chronic kidney damage cases in their study occurred in people who had no acute kidney symptoms along the way. In other words, you wouldn’t necessarily feel it happening.
Magnesium depletion: After about a year of continuous use, the risk of low magnesium increases significantly. Your intestines rely on active transport to absorb magnesium, and omeprazole appears to interfere with that process. Severely low magnesium can cause muscle spasms, irregular heartbeat, and seizures.
Vitamin B12 deficiency: Your stomach needs acid to release B12 from the food you eat. By suppressing that acid, omeprazole can reduce B12 absorption over time. Clinically meaningful deficiency is unlikely unless you’ve been on the drug for two or more years, you’re taking a high dose, or your dietary B12 intake is already low. People in those categories should have their levels checked.
Bone fracture risk: Reduced stomach acid also affects calcium absorption. Over years of use, this has been linked to increased fracture risk, particularly in the hip, wrist, and spine.
How to Stop Safely
You can’t always just quit omeprazole cold turkey, especially after weeks or months of use. Your stomach compensates for the suppressed acid by ramping up its acid-producing machinery. When you suddenly stop, all that machinery fires at once, producing more acid than you had before you started. This is called rebound acid hypersecretion, and it can make your symptoms temporarily worse than they were originally.
The recommended approach is a gradual taper over two to four weeks. Higher doses need longer tapers. During this period, you might step down to a lower dose, switch to every-other-day dosing, or transition to a milder antacid. Rebound symptoms, when they occur, typically last 10 to 14 days and then resolve on their own.
After stopping, a check-in around four weeks out helps confirm your symptoms are staying under control. A second check at about 12 weeks gives a clearer picture of whether you can stay off the medication or whether you need a different long-term strategy.