What Does Aluminum Magnesium Do for the Body?

December 11, 2025 •

4 min read

According to MedlinePlus, aluminum hydroxide and magnesium hydroxide are common ingredients in antacids used to neutralize stomach acid and provide relief from heartburn and acid indigestion. The combination, often referred to colloquially as "aluminum magnesium," is specifically formulated to balance the effects of each mineral on the digestive system.

Quick Summary

The combination of aluminum and magnesium is primarily utilized in antacids to neutralize stomach acid. Magnesium acts as a laxative, while aluminum can cause constipation, creating a balanced effect. This formulation addresses symptoms of acid indigestion, heartburn, and upset stomach, but long-term or excessive use carries risks like aluminum toxicity, especially for those with kidney issues. Proper dosage and consulting a healthcare provider are important.

Key Points

Antacid Action: The primary role of the aluminum and magnesium combination is to neutralize stomach acid for fast relief of heartburn and indigestion.
Balanced Effects: In antacids, magnesium acts as a laxative while aluminum causes constipation, creating a balanced effect that prevents severe digestive side effects.
Magnesium's Essential Role: As an essential mineral, magnesium supports hundreds of bodily functions, including nerve and muscle function, blood pressure regulation, and bone health.
Aluminum Toxicity Risk: Aluminum is non-essential and can be toxic if it accumulates, particularly in individuals with impaired kidney function, leading to potential neurological and bone issues.
Safe Medication Use: Long-term use of aluminum-containing antacids should be avoided, and individuals with kidney disease should consult a doctor before use due to toxicity risks.
Drug Interactions: These antacids can interfere with the absorption of other medications, so it's important to separate dosing times by at least two hours.

The Combined Action of Aluminum and Magnesium

In the context of over-the-counter (OTC) medicine, aluminum and magnesium are most commonly found together in antacids. The key to their combined use is a balancing act: magnesium compounds, such as magnesium hydroxide, have a laxative effect, while aluminum compounds, like aluminum hydroxide, tend to cause constipation. By combining the two, manufacturers create a formula that provides effective neutralization of stomach acid without causing significant digestive side effects like severe constipation or diarrhea.

This neutralization process occurs when these alkaline compounds react with the hydrochloric acid in the stomach, raising the gastric pH and reducing the acidity. This rapid action provides symptomatic relief for conditions such as:

Heartburn
Acid indigestion
Sour stomach
Upset stomach
Gas and bloating (especially when combined with simethicone)
Symptoms related to GERD, peptic ulcer, and gastritis

The Role of Magnesium in the Body

Beyond its role in antacids, magnesium is an essential mineral vital for hundreds of bodily functions. The average adult body holds about 25 grams of magnesium, with more than half stored in the skeletal system. This "mighty mineral" is involved in critical physiological processes, including:

Enzyme activation: It is a cofactor in over 300 enzyme reactions, many of which are involved in energy production.
Muscle and nerve function: Magnesium helps regulate muscle contractions and nerve impulses, and can alleviate muscle cramps and spasms.
Cardiovascular health: It is crucial for maintaining a steady heart rhythm and regulating blood pressure.
Bone health: Magnesium works alongside calcium and vitamin D to support bone density and formation.
Glucose control: It aids in regulating blood sugar levels and insulin metabolism.

The Role of Aluminum in the Body (and Associated Risks)

Aluminum is a non-essential mineral, and the body does not benefit from its presence. While trace amounts are absorbed from food and the environment, high levels can be toxic, particularly for individuals with kidney problems. The body typically clears aluminum via the kidneys. However, excessive intake, especially through aluminum-containing medications like antacids or phosphate binders, can lead to accumulation and toxicity.

Excessive aluminum accumulation can cause serious health issues, including:

Neurotoxicity: Aluminum can cross the blood-brain barrier and has been linked to neurodegenerative conditions and encephalopathy (often called "dialysis dementia").
Bone disorders: It can interfere with bone formation and increase the risk of osteoporosis and fractures.
Anemia: Aluminum toxicity can inhibit hemoglobin synthesis, leading to anemia.
Gastrointestinal issues: While intended to treat upset stomach, high doses can cause severe constipation.

Comparing Magnesium and Aluminum in Antacids


Feature	Magnesium (e.g., as Hydroxide)	Aluminum (e.g., as Hydroxide)
Function in Antacids	Neutralizes stomach acid.	Neutralizes stomach acid.
Effect on Bowel	Has a laxative effect.	Has a constipating effect.
Systemic Role	Essential mineral, involved in hundreds of metabolic functions.	Non-essential mineral; potentially toxic in high doses.
Key Benefit	Balances the constipating effect of aluminum, provides rapid relief.	Balances the laxative effect of magnesium, provides rapid relief.
Primary Risk	High intake can cause diarrhea; risk of hypermagnesemia in kidney disease.	Toxicity from accumulation, especially in cases of renal impairment.

Safe Use and Considerations for Combined Antacids

For most healthy individuals, using OTC aluminum-magnesium antacids for short-term relief is generally safe. However, long-term or high-dose use is not recommended and should only be done under a doctor's supervision. Individuals with pre-existing kidney disease are particularly vulnerable to aluminum toxicity, and should avoid aluminum-containing antacids entirely unless directed by a healthcare provider.

To ensure proper and safe use:

Consult a doctor: Discuss your symptoms with a healthcare provider, especially if they are chronic or severe.
Follow instructions: Adhere strictly to the dosage and duration recommendations on the product label.
Avoid interactions: Separate the timing of antacid intake from other oral medications by at least 2 to 4 hours, as antacids can interfere with the absorption of other drugs.
Monitor side effects: Be aware of side effects such as severe constipation, persistent diarrhea, muscle weakness, or unusual tiredness.

Conclusion

What does aluminum magnesium do for the body? In their combined form within antacids, they provide a fast-acting and balanced solution for neutralizing excess stomach acid and relieving related digestive discomfort. However, it's critical to distinguish between the body's essential need for the mineral magnesium and its tolerance for the non-essential, potentially toxic, aluminum. By understanding their separate roles and using combination antacids cautiously, consumers can manage acute symptoms effectively while minimizing health risks associated with long-term exposure.

Authority Link

For more in-depth information on aluminum toxicity, refer to the National Center for Biotechnology Information (NCBI) Bookshelf publication on the topic.(https://www.ncbi.nlm.nih.gov/books/NBK609094/)

Frequently Asked Questions

They are combined to balance their opposite effects on the digestive system. Magnesium tends to cause diarrhea, while aluminum causes constipation. By combining them, manufacturers can neutralize stomach acid and provide relief from heartburn without causing significant bowel problems.

For most healthy individuals using antacids for short-term relief, the amount of aluminum absorbed is minimal and not considered harmful. However, excessive or prolonged use can lead to aluminum accumulation, especially in those with kidney disease, which can cause serious health issues like bone disorders and neurological problems.

While the magnesium in these antacids contributes to your intake, it is not the ideal way to supplement for a magnesium deficiency. There are better absorbed forms of magnesium, such as magnesium citrate and glycinate, designed specifically to raise systemic magnesium levels effectively.

Overdosing can lead to severe side effects. The magnesium can cause diarrhea, while the aluminum can cause severe constipation, stomach pain, and potentially other issues from toxicity if kidney function is impaired.

Symptoms of magnesium deficiency can include fatigue, muscle weakness, cramps, irregular heartbeat, and headaches. A blood test is the most accurate way to confirm a deficiency. If you suspect you have a deficiency, consult a healthcare provider.

Yes. Individuals with kidney problems should avoid these antacids due to the risk of aluminum toxicity. It is also not recommended for long-term use and should be used with caution by pregnant or breastfeeding women.

According to MedlinePlus, you should not take these antacids for more than 1 to 2 weeks unless your doctor instructs you to do so. If your symptoms persist, you should seek medical advice.