Twinlab Magnesium Caps, 420 mg, 100 Capsules supplement bottle
Twinlab

Magnesium Caps, 420 mg, 100 Capsules

What We Researched
1 active ingredient analyzed · 7 inactive ingredients decoded · 1 brand certification checked · 2 retailers compared · Last updated: Mar 2026
68
Product Score Fair
64
Brand Score Fair

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
Magnesium (as magnesium oxide) 420 mg 100%
Bioavailability Very Poor

Absorption Rating

  • Magnesium (as magnesium oxide) Poor
Other Ingredients Excellent

Fillers & Additives

  • Gelatin
  • Potato Starch
  • Magnesium Silicate
  • Medium Chain Triglycerides
  • Croscarmellose Sodium
  • Magnesium aspartate
  • Silica
Efficacy Very Good

Dosage Analysis

  • Magnesium (as magnesium oxide) 420 mg High

Supplement Facts

Ingredient Amount % Daily Value
Magnesium (as magnesium oxide) 420 mg 100%

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Gelatin Safe

Forms the capsule shell that holds the supplement contents.

Potato Starch Safe

It is used as a filler or binder in supplements.

Magnesium Silicate Generally_safe

It is used to improve powder flow and prevent clumping.

Medium Chain Triglycerides Safe

Enhances absorption of fat-soluble vitamins.

Croscarmellose Sodium Safe

Helps tablets break apart and dissolve quickly in the stomach.

Magnesium aspartate Unknown
Silica Safe

Prevents ingredients from clumping and improves powder flow.

Price Comparison

Price History

Tracked across major retailers. Updated periodically.

$13$12$11$10$9 Mar 12 $10.99
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
Twinlab

Founded 1968 · Boca Raton, Florida, USA · 14 products · twinlab.com

Certifications

1 certification
Consumerlab Verified Source

Transparency

3 claims
Third Party Testing Claim — Claimed Source
In House Testing — Claimed Source

Violation History

1 incident
Lawsuit Securities fraud, making false and misleading statements, and overstating inventory.2001Source
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Frequently Asked Questions
Is Twinlab Magnesium Caps, 420 mg a good supplement?

Twinlab Magnesium Caps, 420 mg, 100 Capsules received a product quality score of 68/100 in GoodSupp's independent analysis, suggesting some areas that could be improved. The product contains 1 active ingredients with 100 servings per container. Of the 7 inactive ingredients, 5 are rated safe and 0 are flagged for review. The manufacturer, Twinlab, holds a brand trust score of 64/100 with 1 verified certifications including Consumerlab.

What are the ingredients in Twinlab Magnesium Caps, 420 mg?

Twinlab Magnesium Caps, 420 mg contains 1 active ingredients: Magnesium (as magnesium oxide) (420 mg). Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is Twinlab Magnesium Caps, 420 mg safe to take?

Twinlab Magnesium Caps, 420 mg, 100 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 Twinlab a trustworthy supplement brand?

Twinlab receives a brand trust score of 64/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1968 and headquartered in Boca Raton, Florida, USA, the company offers 14 products in their lineup. They hold 1 verified certifications including Consumerlab. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. Note: Twinlab has 1 historical regulatory incident 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.