How Does Milk of Magnesia Work?

Does the term 'milk of magnesia' ring familiar? Most of us have had to count on it on several occasions in our lives. How does it work, though? Let's find out!

Milk of magnesia, in other words, Messiah of the Constipated, is a blessing for those who are condemned to face some really tough (sounds kind of metaphorical? Hell yes, it is!), solitary moments in the morning on a regular basis.

So, how does milk of magnesia work to provide relief to the bowels? Before we get to that part, let's first get to know more about this inorganic compound. Scientifically known as magnesium hydroxide, milk of magnesia is the result of salt metathesis reaction between magnesium salts and sodium hydroxide.

Sodium hydroxide can also be substituted by either potassium hydroxide or ammonium hydroxide. The name milk of magnesia is an allusion to the opaque, white milky appearance of this chemical compound when it is in the form of a water based suspension. In its solid form, magnesium hydroxide exists in the form of the mineral brucite.

Primarily, milk of magnesia finds medical use for relieving both constipation and acidity. There are various other uses of milk of magnesia as well but we'll briefly discuss them in latter segments. Let's see its mechanism of action in both these primary situations.

The laxative effects of milk of magnesia for relieving constipation come from the osmotic function of an oral suspension which, when consumed, serves to absorb fluids from elsewhere in the body (the areas surrounding the intestines, to be specific)...

...and transfers all this fluid to the inner cavity of the intestinal tube and also retains the fluids that are already present therein.

This leads to the bowels getting extended due to pressure of the accumulated fluids exerted from within. Such distension of the bowels leads to stimulation of the nerves that run along the intestinal walls, leading to increased activity in the colon, finally resulting in the emptying of its fecal contents.

Having a mild alkaline pH, milk of magnesia is effective in neutralizing stomach acids, thereby reducing acidity and providing relief in mild to moderate cases of heartburn and acid reflux. Similar to the standard acid-base reaction, salt and water result when milk of magnesia comes in contact with stomach acids. These, then, usually get expelled via urine or feces.

Depending upon individual receptivity and the quantity and frequency of milk of magnesia dosage, it may take anywhere between 30 minutes to 4 hours for the MOM suspension to show any perceptible effect.

Complete relief can be expected anywhere between 8 hours to about a day, with chemists and physicians usually recommending a nocturnal intake for total relief in the morning in case of constipation. In case of acidity, the relief is almost immediate.

However, to avoid dependency and to prevent excess milk of magnesia from intruding upon the digestive process, it is advised not to take this suspension for more than a week at a stretch. If constipation or acidity persists even after 3 doses of recommended quantity each (usually once a day, before hitting the sack), it's best to discontinue its intake and consult a physician.

Milk of magnesia, in small doses, is effective in correcting mild cases of indigestion as well. Besides treating constipation, dyspepsia and acidity, milk of magnesia is also used as a home remedy for treating and clearing dandruff. Magnesium hydroxide suspensions are often also used as a traditional remedy against acne, dermal flaking and oily skin.

Due to its ability to draw fluids, magnesium hydroxide is an active ingredient in antiperspirant products and deodorants. Topical application on mouth ulcers is also believed to relieve the discomfort and burning sensation thereupon.