Magnesium carbonate is a compound that is used in some over-the-counter (OTC) antacid preparations as an active ingredient to neutralize excess stomach acid. It works by reacting with stomach acid to form magnesium chloride and carbon dioxide, which helps to neutralize the acid and reduce symptoms of heartburn, indigestion, and acid reflux.
Some OTC antacid products containing magnesium carbonate are available in tablet or powder form and are taken orally to provide fast relief of symptoms. The magnesium carbonate in these products works quickly and effectively to neutralize stomach acid and provide relief from heartburn and indigestion.
It’s important to note that magnesium carbonate can cause side effects in some people, such as diarrhea or constipation, so it is important to follow the dosing instructions on the product label and consult a healthcare professional before using antacid products containing magnesium carbonate, especially if you have any underlying health conditions or are taking any prescription medications.
In conclusion, magnesium carbonate is a common ingredient in OTC antacid preparations and can be effective in neutralizing excess stomach acid and providing relief from symptoms of heartburn, indigestion, and acid reflux.
Magnesium Carbonate Over-The-Counter (OTC) Antacid Preparations
Here are some over-the-counter (OTC) antacid products that contain magnesium carbonate as an active ingredient:
- Tums: Tums is a popular antacid brand that offers a variety of products containing calcium carbonate, magnesium carbonate, or both.
- Rolaids: Rolaids is another popular antacid brand that offers a variety of products containing calcium carbonate and magnesium carbonate.
- Maalox: Maalox is an antacid brand that offers products containing aluminum hydroxide, magnesium hydroxide, and magnesium carbonate.
- Alka-Seltzer: Alka-Seltzer is a well-known antacid brand that offers products containing aspirin, citric acid, and baking soda, as well as antacid products containing calcium carbonate and magnesium carbonate.
These are just a few examples of OTC antacid products that contain magnesium carbonate. It’s always important to read the label and follow the dosing instructions on the product, as well as to consult a healthcare professional if you have any concerns or questions about using these products.
Side Effects
Magnesium carbonate-containing over-the-counter (OTC) antacid preparations are generally well tolerated, but some people may experience side effects. Here are some of the most common side effects associated with using antacids containing magnesium carbonate:
- Diarrhea: Magnesium is a natural laxative and excessive intake of magnesium carbonate can cause diarrhea.
- Constipation: Magnesium carbonate can also cause constipation in some people.
- Stomach cramps: In some cases, antacids containing magnesium carbonate can cause stomach cramps.
- Nausea: Some people may experience nausea after taking antacids containing magnesium carbonate.
- Bloating: Antacids containing magnesium carbonate can cause bloating in some people.
It’s important to keep in mind that these side effects are rare and most people do not experience any significant problems when using OTC antacids containing magnesium carbonate. However, if you experience any persistent or severe side effects, you should stop using the product and consult a healthcare professional.
In general, OTC antacids containing magnesium carbonate are safe for occasional use, but if you experience heartburn or acid reflux frequently, it is important to consult a healthcare professional for a proper diagnosis and treatment plan.
Warnings & Precautions
There are some precautions and warnings associated with using over-the-counter (OTC) antacids containing magnesium carbonate. Here are some important things to keep in mind:
- Consult a healthcare professional: If you have any underlying health conditions or are taking prescription medications, it is important to consult a healthcare professional before using OTC antacids containing magnesium carbonate.
- Do not exceed the recommended dose: Antacids containing magnesium carbonate should only be used as directed and in accordance with the dosing instructions on the product label. Excessive use can lead to an overdose of magnesium, which can cause serious health problems.
- Avoid taking antacids at bedtime: Antacids should be taken after meals and at least 2 hours before bedtime to avoid interference with nighttime sleep.
- Do not use for an extended period of time: OTC antacids containing magnesium carbonate should not be used for an extended period of time without consulting a healthcare professional. Long-term use can interfere with the absorption of other minerals and nutrients, and may lead to other health problems.
- Pregnancy and breastfeeding: If you are pregnant or breastfeeding, it is important to consult a healthcare professional before using OTC antacids containing magnesium carbonate.
It’s important to keep these precautions and warnings in mind when using OTC antacids containing magnesium carbonate. If you have any questions or concerns, you should consult a healthcare professional for more information and advice.
Effects of Long-Term Use
Long-term use of over-the-counter (OTC) antacids containing magnesium carbonate can interfere with the absorption of other minerals and nutrients in the body, leading to nutrient deficiencies and other health problems.
For example, high levels of magnesium in the digestive system can interfere with the absorption of calcium, iron, and zinc, leading to deficiencies in these minerals. This can result in a range of health problems, such as osteoporosis, anemia, and weakened immunity.
In addition, long-term use of antacids containing magnesium carbonate can also lead to other health problems, such as kidney damage, because the body may not be able to eliminate excess magnesium effectively.
It’s important to keep these potential health risks in mind when using OTC antacids containing magnesium carbonate and to consult a healthcare professional if you have any concerns or questions about long-term use of these products. Your healthcare professional can help you determine the appropriate course of treatment for your individual needs and help minimize the risk of any negative health effects.

Other Information
Here are a few additional things you may want to know about over-the-counter (OTC) antacids containing magnesium carbonate:
- How they work: Antacids containing magnesium carbonate work by neutralizing the excess acid in the stomach, thereby reducing symptoms of heartburn and acid reflux.
- Dosage: The recommended dose of OTC antacids containing magnesium carbonate varies depending on the product and the individual. It is important to follow the dosing instructions on the product label and to consult a healthcare professional if you have any questions or concerns.
- Other active ingredients: Some OTC antacids contain other active ingredients in addition to magnesium carbonate, such as calcium carbonate, aluminum hydroxide, or magnesium hydroxide. It is important to understand the active ingredients in the product you are using and to follow the dosing instructions on the product label.
- Limitations: OTC antacids containing magnesium carbonate are intended for occasional use and should not be used as a long-term solution for heartburn or acid reflux. If you experience frequent or persistent symptoms, you should consult a healthcare professional for a proper diagnosis and treatment plan.
- Alternative treatments: If you experience heartburn or acid reflux frequently, there are alternative treatments available, such as prescription medications and lifestyle changes, such as avoiding certain foods, losing weight, and avoiding lying down immediately after eating. Your healthcare professional can help you determine the appropriate course of treatment for your individual needs.
This is a general overview of OTC antacids containing magnesium carbonate. If you have any specific questions or concerns, you should consult a healthcare professional for more information and advice.
ATC Code: A03A DRUGS FOR FUNCTIONAL GASTROINTESTINAL DISORDERS.