Product Label

Natural Factors Magnesium Citrate 150 mg

Brand: Natural Factors · Form: CAPSULE [E0159]

Our assessment

The evidence shows that magnesium citrate, as found in Natural Factors Magnesium Citrate 150 mg, is a well-absorbed form of magnesium often used to support muscle relaxation and regularity. However, the specific data provided here focuses on calcium, not magnesium. Based on the data available for calcium, a related mineral, we can draw parallels about the importance of proper mineral balance, but we must be careful not to apply calcium-specific findings directly to this product. Our assessment is that this supplement can be a useful tool, but you should understand its specific role and limitations.

How it works

Magnesium works in the body as a critical cofactor for hundreds of enzymatic reactions. While the data provided focuses on calcium's mechanism—bone mineralization and neuromuscular relaxation [NIH ODS]—magnesium plays a complementary role. It helps regulate muscle contraction and nerve transmission, and it is essential for energy production. The citrate form is known for being more easily absorbed by the body compared to some other forms, which can be beneficial for improving magnesium status.

Safety profile

Based on the FDA adverse event data, there have been a total of 592,059 reports for all supplements, though specific data for this product is not isolated. For the related mineral calcium, safety data notes that high levels can cause constipation, nausea, and abnormal heart rhythms [NIH ODS]. For magnesium citrate specifically, the most common side effect is loose stools or diarrhea, especially at higher doses. The safety data for calcium also highlights interactions: it can reduce the absorption of certain medications like tetracycline antibiotics and levothyroxine [NIH ODS]. Data for magnesium-specific medication interactions is not available.

Our recommendation

We recommend taking this product with a meal to improve absorption and minimize digestive upset. Start with one capsule (150 mg) daily, and you can increase to two if needed, but be mindful of loose stools. If you take prescription medications, especially antibiotics or thyroid medication, separate your magnesium dose by at least two hours. For personalized advice, especially if you have kidney issues or are on other medications, consult your healthcare provider. This is a solid choice for a gentle magnesium supplement.

AI-assisted analysis. Data sourced from NIH DSLD.

Supplement Facts

BrandNatural Factors
Serving Size
Contents90.0 Capsule(s)
Market StatusOff 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)

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