Qualitest Magnesium Oxide Tablets 400 mg
Brand: Qualitest · Form: TABLET [E0155] On Market
Our assessment
The evidence shows that Qualitest Magnesium Oxide Tablets 400 mg provides a form of magnesium intended to support bone mineralization and neuromuscular relaxation [NIH ODS]. However, we must be clear: the available data on this specific product is limited, and the broader supplement category carries important considerations. Data not available on the specific brand formulation beyond the label.
How it works
Think of magnesium as a mineral regulator for your body. It supports bone density through bone mineralization and helps your muscles relax by aiding nerve signaling [NIH ODS]. The 400 mg dose of magnesium oxide is a common form, but it is less well absorbed than other types like magnesium citrate.
Safety profile
FDA received 592,059 total adverse event reports across all supplement types. For calcium, which is a related mineral, side effects can include constipation, nausea, and abnormal heart rhythms at high levels [NIH ODS] [FDA data]. Data not available on specific adverse event counts for this exact product. High intakes of related minerals might increase risk of heart disease and prostate cancer [NIH ODS].
Our recommendation
Start with one tablet daily, preferably with food to reduce stomach upset. Be aware that magnesium oxide can cause loose stools or diarrhea in some people. Check with your doctor before taking this if you use bisphosphonates, tetracycline antibiotics, or levothyroxine, as minerals can reduce absorption of these medications [NIH ODS]. Choose a more absorbable form if you have known magnesium deficiency.
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | Qualitest |
|---|---|
| Serving Size | |
| Contents | 120.0 Tablet(s) |
| Market Status | On Market |
How to Read This Label
Supplement labels contain several key sections regulated by the FDA:
- Serving Size — The recommended amount per dose. Always check this — some products require multiple capsules per serving.
- Amount Per Serving — Shows the quantity of each nutrient in the product, typically in IU (International Units), mg (milligrams), or mcg (micrograms).
- % Daily Value (%DV) — Indicates how much a nutrient in a serving contributes to a daily diet. 5% DV or less is low; 20% DV or more is high.
- Other Ingredients — Lists inactive ingredients like fillers, binders, and capsule materials (e.g., gelatin, cellulose, magnesium stearate).
- Suggested Use — The manufacturer's recommended directions for taking the supplement, including timing and dosage.
Source: FDA Dietary Supplement Labeling Guide