NOW Magnesium Oxide
Brand: NOW · Form: POWDER [E0162]
Our assessment
The evidence shows that magnesium is a foundational mineral for your body, but our assessment of NOW Magnesium Oxide is that it is a less absorbable form of magnesium compared to other types like citrate or glycinate. While it can help with general magnesium intake, you may need a higher dose to achieve the same effect as other formulations. Data not available for specific health outcomes for this specific product.
How it works
Think of magnesium as a multi-tool for your cells. It supports bone mineralization and helps your nervous system relax by regulating muscle contraction and nerve signaling [NIH ODS]. Because this product uses magnesium oxide, it is not as easily absorbed by your body as other forms, which means more of it may pass through your digestive system rather than being used for these critical functions.
Safety profile
FDA received 592,059 total adverse event reports for products containing calcium. However, specific side effect data for this exact magnesium product is not available. Based on general mineral supplement safety, high levels can cause constipation, nausea, and poor muscle tone [NIH ODS]. You should be aware that calcium supplements can reduce the absorption of medications like bisphosphonates, tetracycline antibiotics, and levothyroxine [NIH ODS].
Our recommendation
We recommend you consider a different form of magnesium, such as magnesium citrate or glycinate, for better absorption. If you choose this product, start with a low dose and take it with food to minimize digestive upset. Always consult your doctor before starting any new supplement, especially if you take prescription medications [NIH ODS].
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | NOW |
|---|---|
| Serving Size | |
| Contents | 8.0 oz. 227.0 g |
| Market Status | Off 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