Milk of magnesia is a medication with a laxative and antacid action. It contains magnesium hydroxide in its composition, and is prescribed for treating constipation or relieving heartburn.

This medication can be found in pharmacies in the form of an oral suspension.

Although it is sold over-the-counter, milk of magnesia should be used as prescribed by a doctor depending on the symptoms presented and the condition being treated. Consuming doses above the recommended amount can cause abdominal pain and severe diarrhea, which can lead to severe dehydration.

What it's used for

Milk of magnesia has antacid and laxative action and is prescribed for the treatment of:

Constipation
Heartburn
Indigestion
Excessive acidity in the stomach

This medication works by reducing stomach acidity that contributes to heartburn, and by increasing water retention in the gut, to promote bowel movements.

Milk of magnesia is also popularly used to reduce foot and armpit odor and to treat or prevent acne. It promotes skin alkalinization and prevents the proliferation of microorganisms. However, there are no scientific studies that support the benefits of milk of magnesia for the skin and skin use should only be done if prescribed by a doctor.

The use of milk of magnesia should always be done as prescribed, depending on the condition being treated.

How to take

Milk of magnesia must be taken orally and can be diluted in water before use or taken in its pure form. It is important to shake the bottle before use to mix the formula ingredients.

The normally recommended doses vary according to the indication, and include:

1. Laxative purposes

Milk of magnesia as a laxative can be used by adults or children over 2 years of age, with normally recommended doses varying with age and include:

Adults or children over 12 years of age: the normally recommended dose is 2 to 4 tablespoons of milk of magnesia per day, which is equivalent to 30 to 60 mL per day, taken as prescribed;
Children between 6 and 11 years old: the normally recommended dose is 1 to 2 tablespoons of milk of magnesia per day, which is equivalent to 15 to 30 mL per day, taken as prescribed by the pediatrician;
Children between 2 and 5 years old: the normally recommended dose is 1 teaspoon (5 mL) to 1 tablespoon of milk of magnesia (15 mL) per day, taken as prescribed.

Milk of magnesia as a laxative can be taken for a maximum of 3 days in a row, or as prescribed by your doctor.

2. Milk of magnesia as an antacid

The normally recommended doses of milk of magnesia as an antacid are:

Adults and children over 12 years of age: the normally recommended dose is 1 teaspoon (5 mL) to 1 tablespoon (15 mL), up to 3 times a day, or as prescribed by a doctor. The maximum dose of milk of magnesia is 45 mL every 24 hours;
Children between 2 and 11 years old: the normally recommended dose is 1 teaspoon (5 mL) of milk of magnesia. This dose can be repeated as advised by the pediatrician, up to a maximum of 30 mL of milk of magnesia every 24 hours.

Milk of magnesia as a laxative can be used for a maximum of 14 consecutive days of treatment, within the doses prescribed by the doctor.

When to take it

To treat constipation, the best time to take milk of magnesia is at night, before bed, as it takes 30 minutes to 6 hours to stimulate bowel movements.

If you are taking it to reduce stomach acidity, you should take milk of magnesia after eating.

Possible side effects

Side effects of milk of magnesia generally occur when consumed in excessive amounts or for prolonged periods of time, and can include abdominal pain, diarrhea, stomach, intestinal irritation, or dehydration.

Magnesium poisoning is also a risk, and is a serious situation that requires immediate medical attention. Uou should seek urgent medical attention if you experience symptoms such as nausea, vomiting, facial redness, excessive thirst, drowsiness, mental confusion, loss of reflexes, muscle weakness, feeling short of breath, irregular heartbeat or fainting after taking milk of magnesia.

Contraindications for use

Milk of magnesia should not be used by children under 2 years of age, by people with kidney disease or by anyone who is allergic to magnesium hydroxide or any other component of the formula.

Furthermore, milk of magnesia should not be used by pregnant or breastfeeding women unless instructed to do so by their doctor. Check-out home remedies for heartburn during pregnancy that are safe for use.