Product Label

21st Century Magnesium 250 mg

Brand: 21st Century · Form: TABLET [E0155] On Market

Our assessment

The evidence shows that this product provides 250 mg of magnesium per serving. However, the data provided only describes calcium, not magnesium. Based on the information available, we cannot assess the specific benefits or risks of this magnesium supplement. Data for magnesium’s mechanism of action, safety, and interactions is not available in the provided materials.

How it works

For the ingredient calcium, which is not the primary ingredient in this product, the data indicates it supports bone mineralization and neuromuscular relaxation [NIH ODS]. Since the product contains magnesium, and no specific data for magnesium was provided, we must state: data on how this specific supplement works is not available.

Safety profile

FDA received a total of 592,059 adverse event reports across all supplement products, but this number is not specific to this magnesium supplement [FDA data]. For the ingredient calcium (which is not in this product), high intakes may increase the risk of heart disease and prostate cancer, and can cause constipation, nausea, and abnormal heart rhythms [NIH ODS]. Because the product is magnesium, and no side effect data for magnesium was provided, data on side effects for this specific product is not available.

Our recommendation

Our assessment: without specific data on magnesium from the provided sources, we cannot make a confident recommendation for this product. Data for magnesium’s RDA, drug interactions, and clinical studies is not available. We advise you to consult a healthcare provider before starting any new supplement, especially when specific safety and efficacy data is missing.

AI-assisted analysis. Data sourced from NIH DSLD.

Supplement Facts

Brand21st Century
Serving Size
Contents110.0 Tablet(s)
Market StatusOn 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

Original Label

View Full DSLD Label (PDF)

Similar Products from 21st Century