Messi Biology states that while many associate magnesium hydroxide with industrial flame retardants, it is actually a “versatile player” in the pharmaceutical field. As a classic pharmaceutical excipient and active ingredient, pharmaceutical-grade magnesium hydroxide is widely used in the treatment of gastrointestinal diseases and mineral supplementation due to its mild and safe characteristics. It is a common “guardian” in family medicine cabinets, and its medicinal value has long been clinically validated.
The most core application of pharmaceutical-grade magnesium hydroxide is as an antacid to relieve discomfort related to excessive gastric acid. As a weak alkaline compound, it undergoes a neutralization reaction with hydrochloric acid in the stomach after oral administration, producing magnesium chloride and water. This rapidly reduces gastric acidity and relieves symptoms such as heartburn, acid reflux, and stomach pain. Compared to strong alkaline antacids like sodium bicarbonate, its effect is gentle and long-lasting. Furthermore, the neutralization process does not produce carbon dioxide gas, thereby avoiding side effects such as bloating and belching. This makes it particularly suitable for the short-term relief of symptoms in patients with gastric and duodenal ulcers. In clinical practice, it is often used as a core component of compound gastrointestinal medicines, paired with ingredients like aluminum hydroxide to create a synergistic effect that both quickly suppresses acid and extends the duration of efficacy.
As an osmotic laxative, it serves as a “gentle solution” for chronic constipation. When taken orally, magnesium hydroxide is not absorbed by the intestines. Instead, it increases the osmotic pressure within the intestinal tract, “drawing” water from the blood vessels of the intestinal wall into the gut. This softens the stool and stimulates intestinal peristalsis, thereby promoting bowel movements. This mechanism avoids direct irritation of the intestinal mucosa. Compared to stimulant laxatives like senna, it is more suitable for patients with long-term constipation to regulate their bowel habits and can also be used for preoperative bowel preparation. At conventional adult doses, it typically takes effect within 6 to 12 hours with mild side effects; only a small number of people may experience transient bloating, which can be relieved by adjusting the dosage.
It is also a safe magnesium supplement. Magnesium is an essential mineral for the human body, participating in hundreds of physiological processes such as nerve conduction, bone metabolism, and myocardial contraction. Magnesium deficiency can lead to muscle cramps, insomnia, and abnormal blood pressure. Pharmaceutical-grade magnesium hydroxide has a high magnesium content (approximately 42%) and a moderate intestinal absorption rate, making it suitable for nutritional supplementation in magnesium-deficient populations—especially the elderly, vegetarians, and patients with chronic diarrhea. Compared to other magnesium supplements, it causes less gastrointestinal irritation and offers higher safety, allowing for long-term use under a doctor’s guidance.
Furthermore, it is used as a pharmaceutical excipient. In tablets and capsules, magnesium hydroxide is often used as a filler and disintegrant due to its strong stability and good flowability, helping drugs take shape and dissolve quickly in the body for rapid effect. In suspension formulations, it can improve drug dispersibility and extend shelf life.
From relieving stomach pain to regulating bowel movements and supplementing minerals, pharmaceutical-grade magnesium hydroxide has become a “guardian” of gastrointestinal health thanks to its mild, safe, and multi-functional properties. With the advancement of pharmaceutical technology, its dosage forms continue to diversify—from suspensions and tablets to chewable tablets—better meeting the needs of different populations and continuing to safeguard human health.