Magnesium Hydroxide - Uses - Dosages - Side Effects - Precautions

Magnesium Hydroxide: Frequently Asked Questions Answered

What is magnesium hydroxide?

Magnesium hydroxide – Mg(OH)2 – is an inorganic compound found in nature as a mineral.

Magnesium hydroxide is a white powder that has low solubility in water. The addition of calcium hydroxide (milk of lime) to seawater produces magnesium hydroxide.

We see the use of magnesium hydroxide in the preparation of antacids and laxatives, such as milk of magnesia. These antacids and laxatives relieve stomach-related problems like constipation, dyspepsia or indigestion, and heartburn.

What are the uses of magnesium hydroxide?

    • One of magnesium hydroxide’s primary uses is to treat constipation. It works by reducing stomach acid and increasing the water content in the intestine. This helps promote bowel movements. 
    • It is used as an antacid to treat indigestion (often called sour stomach) and stomach upsets, which works by lowering the acid in the gastric juices of the stomach.
    • It is applied topically to treat canker sores in the mouth.

    It is also an ingredient in antiperspirants.

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What are the side effects of magnesium hydroxide?

Many people do not experience any serious side effects with magnesium hydroxide. If your doctor has prescribed this, its benefits are far greater than the risk of side effects.

Long-term or high dosage of magnesium hydroxide may have side effects like:

  • Diarrhea
  • Nausea
  • Vomiting
  • Mineral imbalance
  • Weakness
  • Dizziness

Consult our experts at Yashoda Hospitals if you are suffering from any of these symptoms, or in case of a medical emergency.


Frequently Asked Questions about Magnesium Hydroxide

1. Is magnesium hydroxide a strong base?

No. Magnesium hydroxide has a low solubility in water, which makes it a weak base. The amount of magnesium hydroxide dissolved will completely separate into magnesium and hydroxyl ions (Mg2+ and OH-). Therefore, however weak it may be as a base, magnesium hydroxide is considered a strong and potent electrolyte due to this complete dissociation of ions.

2. Is magnesium hydroxide an alkali?

Magnesium hydroxide contains one magnesium ion bound to two hydroxyl ions. However, it is a peculiarly weak alkali since it does not dissolve completely in water. However, whatever is dissolved makes a strongly basic solution, as it completely dissociates into positively-charged magnesium and negatively-charged hydroxyl ions: Mg2+ and OH-.

3. What is magnesium hydroxide in deodorant?

Magnesium hydroxide is used as an ingredient in deodorants. The main reason for its use is its ability to kill odor-causing bacteria on the skin while causing no damage to the dermis. The dermis is the outermost layer of the skin comprising sweat glands, hair follicles, and pores.

4. Is magnesium hydroxide a salt?

Yes. Magnesium forms many salts with negatively charged ions, such as carbonate, citrate, sulfate, hydroxide, oxide, and trisilicate. Magnesium hydroxide, also known as milk or cream of magnesia, is one such salt of magnesium. Magnesium hydroxide is combined with aluminum hydroxide to make a laxative for treating constipation.

5. How does magnesium hydroxide neutralize stomach acids?

Magnesium hydroxide neutralizes gastric acid in the stomach when used in antacids. Since it is insoluble in water, it does not cause any reaction until it reaches the hydrochloric acid present in the gastric juices. It combines with this stomach acid to form water and magnesium chloride, effectively reducing acidity.

6. Is magnesium hydroxide harmful?

Overdose of magnesium hydroxide can cause nausea, vomiting, rectal bleeding, etc. When we ingest concentrated magnesium hydroxide, it acts as a strong irritant and can damage the skin, eyes, lungs, and stomach. Ingestion of high, concentrated, or long-term use of magnesium hydroxide can worsen your digestive issues instead.

7. Will magnesium hydroxide help me sleep?

Several studies show that magnesium supplements can help regulate the sleep cycle and promote better sleep quality. Magnesium alleviates sleeping disorders like insomnia by reducing stress and elevating mood. It increases GABA, a neurochemical, which relaxes the mind and improves sleep. Therefore, magnesium hydroxide may help you achieve more peaceful sleep. However, consult your doctor if you’re consistently having trouble sleeping.

8. When should I take magnesium hydroxide?

Magnesium hydroxide is taken to treat constipation and stomach-related problems. However, your doctor will be the one to decide your dosage depending upon your health condition. It is preferable to take magnesium hydroxide before bedtime, as it causes bowel movements within 30 minutes to 6 hours after consumption.

9. Is magnesium hydroxide bad for the kidneys?

Excess magnesium levels in the body may cause kidney damage. Overdose or long-term use of magnesium hydroxide will elevate magnesium levels. People with proven excessive magnesium levels and those suffering from kidney dysfunction should avoid antacids, supplements, laxatives, or any other medication containing magnesium, as it may lead to magnesium toxicity.

10. Is magnesium hydroxide a carcinogen?

There has been no research proving that magnesium hydroxide is a carcinogen. Therefore, it is completely safe to take magnesium hydroxide by mouth or apply it to the skin as antacids or topical ointments. There has been no record of cancer caused by magnesium hydroxide in humans to date.



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      Disclaimer: The information provided herein is accurate, updated and complete as per the best practices of the Company. Please note that this information should not be treated as a replacement for physical medical consultation or advice. We do not guarantee the accuracy and the completeness of the information so provided. The absence of any information and/or warning to any drug shall not be considered and assumed as an implied assurance of the Company. We do not take any responsibility for the consequences arising out of the aforementioned information and strongly recommend you for a physical consultation in case of any queries or doubts.