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Magnesium Caps 420 mg

Twinlab
4.6
(461 ratings)
Magnesium 420 mg
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Score89

A high-potency magnesium oxide capsule for basic mineral repletion and gut health.

How scoring works
Quantity:100 Capsule(s)(100 servings)
Goals:
Cardiovascular Support
Energy
Digestive Health
Stress Relief
Heart Health
General Health

Score 89

A high-potency magnesium oxide capsule for basic mineral repletion and gut health.

How scoring works
$9.34($0.09 per serving)
Vitacost
$ 10.99
Pure Formulas
$ 10.99
Amazon
$ 37.95
Walmart
$ 12.65
iHerb
$ 10.99
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Analysis

Each capsule provides 420 mg of magnesium oxide. This form is often used to help with regularity and support bowel motility through its osmotic action in the intestines.

While not the best choice for high-level nervous system support due to its lower absorption, it provides a meaningful amount of elemental magnesium. It's an economical choice for someone who needs a straightforward mineral supplement for general wellness.

Pros

  • High 420 mg dose
  • Very affordable price
  • Supports bowel regularity
  • Easy-to-take capsule form

Cons

  • Poor systemic absorption
  • Higher risk of laxative effects
  • Lacks calming chelates

Warnings

  • Take with food to minimize discomfort
  • Drink plenty of water

Nutrient quality

74 High impact

Reliance on magnesium oxide significantly limits the systemic bioavailability of the mineral. Dosing is high, which may cause digestive issues given the inorganic form used.

Ingredient transparency

100 Highest impact

Elemental weights and the specific mineral source are clearly identified for the consumer. Disclosure of excipients and intake guidance follows standard industry practices.

Customer satisfaction

88 Highest impact

Strong ratings from a moderate pool of reviewers suggest consistent product reliability. Feedback indicates effective outcomes for regularity despite the lower bioavailability.

Value for money

95 Highest impact

Cost per serving is exceptionally low, representing excellent market value for a basic mineral. Value is high for those on a budget, though it sacrifices mineral absorption.

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Goals

Impact
Highest effect
A+ Goal FitB- Strength of SupportB- CoverageA+ Formula Quality

Magnesium is a critical mineral for maintaining healthy blood pressure and a steady heart rhythm. A 420 mg dose provides foundational support for vascular relaxation and cardiac electrical stability.

Utilization of magnesium oxide represents an inorganic form that is generally less bioavailable than organic chelates. For focused cardiovascular support, organic forms like citrate or glycinate are often preferred for their superior absorption and systemic utility.

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Impact
Highest effect
A+ Goal FitC+ Strength of SupportC CoverageA+ Formula Quality

Magnesium acts as a mandatory cofactor for hundreds of enzyme systems, including those that generate and utilize ATP for cellular fuel. This supplement addresses mineral gaps that contribute to physical and mental exhaustion.

Providing 420mg per capsule ensures meaningful support for cellular fuel pathways and metabolic efficiency. However, the use of magnesium oxide represents a lower-tier form with very low systemic bioavailability compared to chelated alternatives.

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Impact
High effect
A- Goal FitC+ Strength of SupportC- CoverageA+ Formula Quality

Magnesium oxide appears well aligned with the goal of promoting gastrointestinal motility and management of occasional constipation through its osmotic effects. This single-ingredient formula provides a material dose for addressing regularity concerns and encouraging bowel comfort.

The 420 milligram dose is at the top of the standard therapeutic range for functional support of gut motility. While the oxide form is known for having poor systemic absorption, it remains effective for providing local support within the digestive tract.

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Impact
High effect
A Goal FitC+ Strength of SupportD+ CoverageA Formula Quality

Magnesium serves as a foundational mineral for regulating the hypothalamic-pituitary-adrenal axis and calming excessive nerve activity. A dose of 420mg appears well-aligned with requirements for daily relaxation and muscle tension relief.

Maintaining adequate magnesium status is essential for supporting a resilient stress response and cognitive focus during demanding periods. However, the use of magnesium oxide significantly reduces the systemic bioavailability of the mineral compared to organic chelates.

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Impact
High effect
A- Goal FitC+ Strength of SupportC- CoverageB Formula Quality

Magnesium is the primary active, provided in a 420 mg capsule for heart support.

Alignment with heart health is foundational, although the use of low-bioavailability mineral forms limits overall effectiveness.

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Impact
High effect
B+ Goal FitC+ Strength of SupportD CoverageA- Formula Quality

This supplement delivers 420 mg of Magnesium in its inorganic oxide form. Magnesium is a critical foundational mineral for hundreds of bodily processes, but the oxide form is known for having poor systemic absorption.

While the product provides a high quantity of the mineral, its low bioavailability may limit its effectiveness for systemic health goals. It is a very basic option that may be more suitable for digestive regularity than general cellular support.

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Ingredients

IngredientAmount per serving
Magnesium (Magnesium Oxide)
420 mg
Adults 18–50
Report overview
F Active Ingredient Quality & BioavailabilityA Dose, Safety & Label TransparencyA Value
Magnesium oxide is a very low-quality form for systemic use due to its poor absorption rates. While it is inexpensive and provides an appropriate dose, choosing a more absorbable form like glycinate would be more effective.
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