Douglas Laboratories Magnesium Oxide, 500 mg, 250 Capsules supplement bottle
Douglas Laboratories

Magnesium Oxide, 500 mg, 250 Capsules

What We Researched
1 active ingredient analyzed · 3 inactive ingredients decoded · 5 brand certifications checked · 2 retailers compared · Last updated: Mar 2026
62
Product Score Fair
95
Brand Score Excellent

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
Magnesium (from 500 mg Magnesium Oxide) 300 mg 75%
Bioavailability Very Poor

Absorption Rating

  • Magnesium (from 500 mg Magnesium Oxide) Poor
Other Ingredients Good

Fillers & Additives

  • Cellulose
  • Gelatin (Capsule)
  • Vegetable stearate and titanium dioxide High
Efficacy Excellent

Dosage Analysis

  • Magnesium (from 500 mg Magnesium Oxide) 300 mg Effective

Supplement Facts

Ingredient Amount % Daily Value
Magnesium (from 500 mg Magnesium Oxide) 300 mg 75%

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Cellulose Safe

Provides bulk and structure in tablets and capsules.

Gelatin (Capsule) Safe

It is used as a material for making capsules.

Vegetable stearate and titanium dioxide Unknown

Price Comparison

Price History

Tracked across major retailers. Updated periodically.

$21$20$19$18$17 Mar 12 $19.40
Vitacost

Prices shown at time of last check. Click a retailer to see current price. GoodSupp is not affiliated with any retailer.

Brand Trust Report
Douglas Laboratories

Founded 1955 · Pittsburgh, Pennsylvania, United States · 32 products · douglaslabs.com

Certifications

5 certifications
Consumerlab Verified Source
Fda Gmp Inspections Verified Source
Nsf Certified For Sport Verified Source
Nsf Gmp Verified Source
Usda Organic Verified Source

Transparency

4 claims
Third Party Testing Claim — Verified Source
Coa Availability — Verified Source
In House Testing — Verified Source

Violation History

2 incidents
Recall Douglas Labs Stress-B-Plus2024-10-07Source
Prop 65 Lead2008-10-22Source
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Frequently Asked Questions
Is Douglas Laboratories Magnesium Oxide, 500 mg a good supplement?

Douglas Laboratories Magnesium Oxide, 500 mg, 250 Capsules received a product quality score of 62/100 in GoodSupp's independent analysis, suggesting some areas that could be improved. The product contains 1 active ingredients with 250 servings per container. Of the 3 inactive ingredients, 2 are rated safe and 0 are flagged for review. The manufacturer, Douglas Laboratories, holds a brand trust score of 95/100 with 5 verified certifications including Consumerlab, Fda Gmp Inspections, Nsf Certified For Sport, Nsf Gmp.

What are the ingredients in Douglas Laboratories Magnesium Oxide, 500 mg?

Douglas Laboratories Magnesium Oxide, 500 mg contains 1 active ingredients: Magnesium (from 500 mg Magnesium Oxide) (300 mg). Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is Douglas Laboratories Magnesium Oxide, 500 mg safe to take?

Douglas Laboratories Magnesium Oxide, 500 mg, 250 Capsules has been analyzed for ingredient safety across all its components. Always consult your healthcare provider before starting any new supplement, especially if you take medications or have underlying health conditions.

Is Douglas Laboratories a trustworthy supplement brand?

Douglas Laboratories receives a brand trust score of 95/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1955 and headquartered in Pittsburgh, Pennsylvania, United States, the company offers 32 products in their lineup. They hold 5 verified certifications including Consumerlab, Fda Gmp Inspections, Nsf Certified For Sport, Nsf Gmp. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. Note: Douglas Laboratories has 2 historical regulatory incidents on record, which are factored into the trust score.

What is magnesium good for?

Magnesium Good For is a topic many supplement consumers ask about. In the context of dietary supplements, understanding magnesium good for helps you make more informed choices about what you put in your body. The quality and form of ingredients matters significantly — two products listing the same ingredient can differ dramatically in bioavailability and effectiveness. GoodSupp analyzes over 250,000 supplement products to help consumers understand exactly what's in their supplements and whether the formulation meets quality standards.

How much magnesium per day?

The optimal dosage depends on your individual health needs, age, sex, and current nutrient levels. Recommended daily amounts are established by health authorities but may vary from therapeutic doses used in clinical research. It's important to check the Supplement Facts label for the exact amount per serving and compare it against the % Daily Value. Some supplements provide mega-doses well above the Daily Value, which may not be necessary and in some cases could be harmful — particularly for fat-soluble vitamins (A, D, E, K) that accumulate in the body. GoodSupp's efficacy analysis evaluates whether a product's dosages align with clinically studied amounts. Always consult your healthcare provider for personalized dosage recommendations.

What is zinc good for?

Zinc Good For is a topic many supplement consumers ask about. In the context of dietary supplements, understanding zinc good for helps you make more informed choices about what you put in your body. The quality and form of ingredients matters significantly — two products listing the same ingredient can differ dramatically in bioavailability and effectiveness. GoodSupp analyzes over 250,000 supplement products to help consumers understand exactly what's in their supplements and whether the formulation meets quality standards.

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Disclaimer: GoodSupp provides independent supplement quality analysis for informational purposes only. Scores are generated algorithmically based on ingredient profiles, brand certifications, and public records. This is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Product data is sourced from manufacturer labels and public databases. GoodSupp is not affiliated with any supplement brand.