Magnesium oxide

Magnesium oxide
ATC Code A02AA02, A06AD02, A12CC10
Formula MgO
Molar Mass (g·mol−1) 40,304
Physical State solid
Density (g·cm−3) 3,58
Melting Point (°C) 2800
Boiling Point (°C) 3600
CAS Number 1309-48-4
PUB Number 14792
Drugbank ID DB01377
Solubility practically insoluble in water


Magnesium oxide is a salt consisting of the elements magneisum and oxygen. In medicine, the compound is commonly used as a laxative for symptomatic relief of acid indigestion and stomach upset, and in dietary supplements for cardiovascular and neuromuscular health.



When taken orally, magnesium oxide acts as a so-called osmotic laxative. This draws fluid from the body into the intestine, increasing stool mass and stimulating nerves in the colon wall. This stimulates intestinal peristalsis and subsequently leads to emptying of the intestinal contents. Dietary magnesium supplements have also been shown to reduce platelet aggregation by inhibiting the influx of calcium, a critical component of platelet aggregation.

Markus Falkenstätter

Markus Falkenstätter

Markus Falkenstätter ist Autor zu pharmazeutischen Themen in der Medizin-Redaktion von Medikamio. Er befindet sich im letzten Semester seines Pharmaziestudiums an der Universität Wien und liebt das wissenschaftliche Arbeiten im Bereich der Naturwissenschaften.

Mag. pharm Stefanie Lehenauer

Mag. pharm Stefanie Lehenauer

Stefanie Lehenauer ist seit 2020 freie Autorin bei Medikamio und studierte Pharmazie an der Universität Wien. Sie arbeitet als Apothekerin in Wien und ihre Leidenschaft sind pflanzliche Arzneimittel und deren Wirkung.

Your personal medicine assistent

afgis-Qualitätslogo mit Ablauf Jahr/Monat: Mit einem Klick auf das Logo öffnet sich ein neues Bildschirmfenster mit Informationen über Medikamio GmbH & Co KG und sein/ihr Internet-Angebot: This website is certified by Health On the Net Foundation. Click to verify.

Search our database for drugs, sorted from A-Z with their effects and ingredients.


All substances with their common uses, chemical components and medical products which contain them.


Causes, symptoms and treatment for the most common diseases and injuries.

The contents shown do not replace the original package insert of the medicinal product, especially with regard to dosage and effect of the individual products. We cannot assume any liability for the correctness of the data, as the data was partly converted automatically. A doctor should always be consulted for diagnoses and other health questions. Further information on this topic can be found here.