Written By : Terry Turner
This page features 8 Cited Research Articles

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GlaxoSmithKline originally developed prescription Zantac, and the U.S. Food and Drug Administration approved it in 1983. In 2004, Pfizer received FDA approval to market an over-the-counter formula. Several other drug companies have been involved in selling it over the years, including Boehringer Ingelheim, Johnson & Johnson and Sanofi SA.

When the drug was still available in the United States, more than 15 million Americans took prescription ranitidine and millions more took the over-the-counter version of the drug, according to Wired.

Zantac is a histamine-2 receptor agonist, or H2 blocker. H2 blockers lower stomach acid by stopping an organic compound called histamine from activating parietal cells that line the stomach. This prevents the stimulation of enzymes called proton pumps and reduces acid in the stomach.

H2 blockers such as ranitidine work fast. They can stop the symptoms of heartburn in as little as 30 minutes and can control acid for up to 12 hours, reducing the severity and frequency of heartburn.

Zantac contains the active ingredient ranitidine in various strengths plus several inactive ingredients, depending on the dose and formula.

Zantac inactive ingredients include:
Zantac 150 Tablet
FD&C 2 35 Yellow No. 6 Aluminum Lake, hypromellose, magnesium stearate, microcrystalline cellulose, 36 titanium dioxide, triacetin, and yellow iron oxide.
Zantac 300 Tablet
Croscarmellose sodium, D&C Yellow No. 10 Aluminum Lake, hypromellose, magnesium 40 stearate, microcrystalline cellulose, titanium dioxide, and triacetin
Zantac Syrup 1 mL
Alcohol (7.5%), butylparaben, 55 dibasic sodium phosphate, hypromellose, peppermint flavor, monobasic potassium phosphate, 56 propylparaben, purified water, saccharin sodium, sodium chloride, and sorbitol


Zantac and generic ranitidine medications come available in tablets, effervescent tablets and syrups, and the recommended dosage changes depending on the condition being treated.

Ranitidine tablets come in strengths from 75 to 300 mg. Capsules come in 150 to 300 mg strengths. Syrup strength is 15 mg/mL and solutions for injection are 25 mg/mL.

How to Take Zantac

Patients typically take prescription ranitidine two to four times a day. People take OTC ranitidine tablets one or twice a day. Zantac can be taken with or without food.

Effervescent tablets or granules should be dissolved in a full glass of water, about six to eight ounces, before drinking.

Patients shouldn’t take Zantac or generic ranitidine for longer than 14 days unless recommended by a doctor. If heartburn, indigestion or upset stomach or other symptoms don’t stop after 14 days, tell your medical provider.

OTC Zantac vs Prescription

OTC Zantac treats heartburn, indigestion and upset stomach, and prescription Zantac treats more serious acid-related conditions, such as GERD, erosive esophagitis and ulcers.

OTC Zantac dosages are lower, and patients shouldn’t take more than two 150 mg tablets in 24 hours. To relieve heartburn, take one tablet with a glass of water. To prevent heartburn, take one tablet 30 to 60 minutes before eating or drinking foods or liquids that cause heartburn.

Prescription Zantac comes in strengths up to 300 mg. Your doctor will prescribe the right dosage depending on the condition being treated.

For example, patients with GERD take 150 mg twice a day. People with erosive esophagitis take 150 mg four times a day.

Side Effects

In general, Zantac doesn’t cause too many side effects. The most common side effect in people who took prescription ranitidine tablets was headache. Serious side effects are rare.

The most common side effects include:
  • Constipation
  • Diarrhea
  • Headache
  • Nausea
  • Stomach Pain
  • Vomiting

Zantac and Cancer

Cancer isn’t a side effect listed on Zantac’s prescription label. But on April 1, 2020, the FDA asked manufacturers to withdraw all ranitidine products from the market because the agency found unacceptable levels of a cancer-causing chemical called N-Nitrosodimethylamine (NDMA) in batches of the medication.

NDMA causes cancer in animals and may cause cancer in humans. The FDA found that NDMA levels in some samples of ranitidine continue to increase over time and when stored at higher than room temperatures. At the time of the recalls, no manufacturers had received reports of adverse events.

The FDA told consumers taking OTC Zantac to stop taking it immediately. The agency told consumers taking prescription Zantac to ask their doctor for alternative medications before stopping treatment.

Research on the types of cancer potentially linked to Zantac is still ongoing.

According to a 2020 article by Richard H. Adamson and Bruce A. Chabner in The Oncologist, researchers at Memorial Sloan Kettering Cancer Center found that taking ranitidine was associated with an increased risk of developing certain cancers.

Researchers surveyed 24,000 patients at Memorial Sloan Kettering Cancer Center and found an increased risk in the odds of presenting with breast, testicular, thyroid and kidney cancer, according to Adamson and Chabner.

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Recalls and Lawsuits

The FDA was first notified of Zantac NDMA contamination in September 2019. At the time of the recall, the agency didn’t have enough information to tell manufacturers to stop selling the drug.

Generic ranitidine manufacturer Sandoz was the first to recall 14 lots of prescription ranitidine in September 2019. Many others recalled ranitidine products in the following months. Consumers can find current information on all lots included in recalls on the FDA’s website.

In April 2020, the FDA expanded the recalls to a complete market withdrawal of all products containing ranitidine. The drug is no longer available in the United States.

Zantac Lawsuit

People diagnosed with cancer after taking ranitidine, including a large number of military veterans who received Zantac prescriptions from the VA, began filing lawsuits claiming that drugmakers failed to warn them of the cancer risk.

The majority of people who filed lawsuits after taking ranitidine didn’t have a family history of cancer or genetic markers for the disease, according to lawyers accepting Zantac cancer cases. Doctors told patients that their cancer was likely caused by something environmental.

Most common cancers in Zantac lawsuits include:
  • Bladder cancer and bladder removal
  • Breast cancer
  • Colon cancer
  • Kidney cancer and kidney removal
  • Liver cancer
  • Prostate cancer
  • Stomach cancer

Other potential cancers include esophageal, pancreatic, ovarian and melanoma.

Zantac Alternatives

Because ranitidine is no longer available on the market, patients may be wondering what medications to take instead of Zantac.

Patients taking prescription Zantac should check with their doctors before stopping their medication. People taking OTC ranitidine can switch to other OTC alternatives.

The FDA recommends proton pump inhibitors and other H2 blockers as Zantac alternatives. These medications don’t contain NDMA.

Proton Pump Inhibitors

Proton pump inhibitors are a class of acid-reducing drugs. When taken every day they can control acid for up to 24 hours. But they may take days to work. They come in OTC and prescription strength.

The FDA recommends the following PPIs as Zantac alternatives:
  • Nexium (esomeprazole)
  • Prevacid (lansoprazole)
  • Prilosec (omeprazole)

H2 Blockers

Other drugs in the H2 blocker class work similar to ranitidine and come in OTC and prescription strength. Like ranitidine, they can relieve heartburn and other symptoms in as little as 30 minutes and last for up to 12 hours.

FDA-recommended H2 blockers include Pepcid (famotidine) and Tagamet (cimetidine).

Please seek the advice of a qualified professional before making decisions about your health or finances.
Last Modified: December 16, 2020

8 Cited Research Articles

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  1. GlaxoSmithKline. (2004). Zantac prescribing information. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2005/018703s065,019675s031,020251s016lbl.pdf
  2. Marill, M.C. (2020, January 10). The FDA Announces Two More Antacid Recalls Due to Cancer Risk. Retrieved from https://www.wired.com/story/the-fda-announces-two-more-antacid-recalls-due-to-cancer-risk/
  3. Reuters. (2019, October 21). Timeline: Popular heartburn medicine Zantac pulled off store shelves. Retrieved from https://www.reuters.com/article/us-health-fda-heartburn-timeline/timeline-popular-heartburn-medicine-zantac-pulled-off-store-shelves-idUSKBN1X014E
  4. U.S. Food and Drug Administration. (2020, April 1). FDA Requests Removal of All Ranitidine Products (Zantac) from the Market. Retrieved from https://www.fda.gov/news-events/press-announcements/fda-requests-removal-all-ranitidine-products-zantac-market
  5. U.S. Food and Drug Administration. (2020, April 16). FDA Updates and Press Announcements on NDMA in Zantac (ranitidine). Retrieved from https://www.fda.gov/drugs/drug-safety-and-availability/fda-updates-and-press-announcements-ndma-zantac-ranitidine
  6. U.S. National Library of Medicine. (2017, December 18). ZANTAC 150- ranitidine tablet. Retrieved from https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=7c6212f5-91fb-438c-80fb-b694c48207b7&audience=consumer
  7. U.S. National Library of Medicine. (2020, June 20). RANITIDINE tablet. Retrieved from https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a2e051e0-e3fa-ce2a-083b-55bff0505384&audience=consumer
  8. U.S. National Library of Medicine. (n.d.). Ranitidine. Retrieved from https://medlineplus.gov/druginfo/meds/a601106.html