Magnesium Oxide Powder

A: Light MgO has lower bulk density (<0.30 g/mL) and a fluffy, high-volume texture, making it suitable for powder blends or capsules where high porosity is acceptable. Heavy MgO has a higher bulk density (0.40–0.65 g/mL) and better flow characteristics, specifically designed for direct compression tablet formulations. For high-speed tableting, we strongly recommend Heavy grade to ensure uniform die fill, reduced capping, and consistent tablet hardness.

A: Traditional in vitro solubility tests (aqueous dissolution) show MgO is poorly soluble in water, leading to claims of low absorption. However, human in vivo studies have challenged this: a randomized clinical trial found that after short-term supplementation, MgO exhibited superior bioavailability compared to other examined magnesium supplements without affecting other mineral levels. Highly active MgO forms can match organic magnesium salts. Additionally, MgO provides sustained Mg²⁺ release over 12–24 hours, which may offer prolonged benefits. The criticism is often based on outdated solubility assumptions rather than clinical absorption data.

A: Our MgO contains approximately 60% elemental magnesium (based on a typical assay of 98.5% MgO). For comparison: magnesium citrate (16% Mg), glycinate (14% Mg), malate (15% Mg), chloride (12% Mg), and lactate (12% Mg). MgO provides the highest mg of elemental magnesium per gram, allowing smaller tablet sizes for the same magnesium dose.

A: No. MgO is practically insoluble in water (0.00062 g/100 mL at 30°C). It will settle quickly and cause turbidity. For clear beverages, we recommend highly soluble magnesium salts such as magnesium citrate, lactate, or chloride. MgO is best suited for tablets, capsules, powder blends, and antacid suspensions.

A: MgO neutralizes gastric acid via a simple acid-base reaction: MgO + 2HCl → MgCl₂ + H₂O. One gram of MgO can neutralize approximately 2.5–3.0 grams of HCl, making it one of the most potent over-the-counter antacid actives. It provides a rapid onset (within minutes) and longer duration compared to calcium carbonate in some formulations.

A: Yes. Under 21 CFR § 184.1(b)(1), the FDA affirms MgO as GRAS (Generally Recognized as Safe) as a direct human food ingredient. There is no specific upper limit for its use in foods under GMP conditions. For supplements, typical doses range from 250 mg to 500 mg MgO per serving. However, buyers must ensure compliance with local regulations in their target markets.

A: MgO can cause osmotic laxative effects at higher doses because unabsorbed magnesium draws water into the intestinal lumen. This effect is dose-dependent. For constipation relief, 400–800 mg MgO is often used. To minimize laxation, lower divided doses or formulation with other ingredients (e.g., fiber, calcium) may help. Unlike magnesium citrate, MgO's lower solubility can result in a slower onset of laxation but sometimes more predictable effects.

A: Shelf life is 36 months when stored properly. MgO is hygroscopic and can absorb moisture from the air, forming magnesium hydroxide and reducing assay. Store in tightly sealed original containers (preferably with desiccant) in a cool, dry place below 25°C, away from humidity. Once opened, reseal immediately and use within 6 months.

A: Yes. The American Academy of Neurology and American Headache Society classify magnesium as "probably effective" for migraine prevention. Most clinical trials used 400–500 mg of MgO daily (equivalent to ~240–300 mg elemental magnesium). Some studies used magnesium citrate or other forms, but MgO is commonly chosen due to its high elemental content and low cost. We recommend consulting clinical guidelines for specific formulation claims.

A: Yes, we supply both Light and Heavy grades as standard. Customization of particle size (e.g., 200 mesh or finer) and bulk density is available upon request. Please provide your target specification, and we will confirm feasibility.