NOW Foods Magnesium Citrate
vs
Source Naturals Ultra-Mag
Supplement Comparison

  • Magnesium: Source Naturals Ultra-Mag has 5.0% more
  • The image below shows:
    • Side-by-side charts with label nutrient amounts, per serving
    • Nutrient forms as listed on the label
    • 5 nutrients compared
Bar chart: per-serving label amounts and listed forms for NOW Foods Magnesium Citrate vs Source Naturals Ultra-Mag.

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Frequently asked questions

Which active ingredients does NOW Foods Magnesium Citrate have?

  • Magnesium appears as Magnesium Citrate

Which active ingredients does Source Naturals Ultra-Mag have?

  • Vitamin B6 (Pyridoxine) appears as Pyridoxine HCl
  • Magnesium appears as Magnesium Citrate, Succinic Acid Complex, Glycinate, Malate, Taurinate Complex
  • Sodium

Which categories do NOW Foods Magnesium Citrate and Source Naturals Ultra-Mag belong to?

  • Single Mineral
  • Mineral Complex

What health concerns do NOW Foods Magnesium Citrate and Source Naturals Ultra-Mag address?

  • Energy & Metabolism
  • General Health
  • Joint & Bone Health
  • Sleep Quality
  • Muscle Support
  • Neurological Support
  • Stress Management

Which product has a higher amount of Magnesium per serving?

  • Source Naturals Ultra-Mag has the highest total amount of Magnesium: 420 mg per serving

How do the serving sizes compare between the two supplements?

  • Serving size:
    • NOW Foods Magnesium Citrate: 2 tablets
    • Source Naturals Ultra-Mag: 2 tablets
  • Vitamin B6 (Pyridoxine)
    • This supplement has 30 mg
    • Recommended Dietary Allowance in men: 1.3 mg
    • Recommended Dietary Allowance in women: 1.3 mg
    • Tolerable Upper Intake Level: 100 mg
  • Sodium
    • This supplement has 30 mg
    • Adequate Intake in men: 1500 mg
    • Adequate Intake in women: 1500 mg
    • Tolerable Upper Intake Level: Not established

Last updated: February 14, 2026

  • Sources & Methodology: Nutrient data and forms are taken directly from Supplement Facts labels. Reviewed and standardized by the VIOscan Research Team. Learn more on the Methodology page.
  • We show the Recommended Dietary Allowance (RDA) when available. If no RDA exists, we show the Adequate Intake (AI). Tolerable Upper Intake Levels (UL) are used for upper limits. Unless otherwise noted, RDAs shown correspond to healthy adults aged 19–50 years and are sex-specific. Separate values exist for 51–70 years and >70 years, and pregnancy and lactation are excluded. All values come from the Dietary Reference Intakes (DRIs) published by the National Academies of Sciences, Engineering, and Medicine (NASEM), Food and Nutrition Board (FNB).
  • Transparency: We’re funded by our users. We don’t have sponsors or affiliate links, and we don’t sell supplements.
  • Editorial standards: we provide independent, impartial and objective data analysis.
  • This analysis is for educational purposes only. It is not a substitute for medical advice.
  • Questions? Read our Frequently Asked Questions or contact us, we’re here to help.
  • See an error? Report it through our Contact page.
  • Author: VIOscan Research Team