NOW Foods
Magnesium Caps 400 mg
86/100
SUPPIE SCORE
75/100
EFFICACY
High
SAFETY
90/100
CLEANLINESS
What Does Magnesium Caps 400 mg Do?
This NOW Foods Magnesium 400 mg supplement provides a solid dose for supporting energy, muscle, and nerve health with strong evidence for magnesium benefits, though mixed forms limit bioavailability. Safe for most adults but may cause GI upset; ideal for deficiency correction.
What are the potential benefits of 400 mg magnesium for muscle cramps and energy production?
Are there any dietary sources of magnesium that could complement this supplement?
Is Magnesium Caps 400 mg a good fit for my goals?
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What Are the Benefits of Magnesium Caps 400 mg?
Based on proven scientific research
Energy ProductionStrong
Muscle FunctionVery strong
Nervous System SupportStrong
Bone HealthModerate
Sleep QualityModerate
Good For:
What Are the Side Effects of NOW Foods Magnesium Caps 400 mg?
Always consult your health practitioner if in doubt.
RiskLow Risk
Overview
•Magnesium at 400 mg elemental exceeds the 350 mg supplemental UL, potentially causing GI side effects like diarrhea, nausea, or stomach cramps in sensitive individuals, though total intake including diet remains safe for most.
•The blend of magnesium oxide (low bioavailability), citrate (laxative effect), and aspartate (better absorbed) may lead to inconsistent absorption and increased risk of loose stools compared to more bioavailable single forms like glycinate.
•Low risk of serious interactions for healthy adults, but may reduce absorption of antibiotics (e.g., tetracyclines, quinolones) or bisphosphonates if taken simultaneously; separate by 2-4 hours.
•Not recommended for individuals with kidney disease, as impaired excretion can lead to hypermagnesemia; consult a doctor for those with heart conditions or on diuretics.
•Safe for pregnancy and breastfeeding at RDA levels (350-400 mg total), but supplemental 400 mg may exceed needs; monitor for GI upset and consult healthcare provider.
•Vegan-friendly with no major allergens, but produced in a GMP facility handling wheat, gluten, soy, milk, egg, fish, shellfish, tree nuts, and sesame, posing cross-contamination risk for severe allergies.
Potential Side Effects
Negative Interactions
Allergens
Potential cross-contamination: wheatglutensoymilkeggfishshellfishtree nutssesame
Inactive Ingredients
Hypromellose (cellulose capsule)
Low RiskMicrocrystalline cellulose
Low RiskStearic acid (vegetable source)
Low RiskSilicon dioxide
Low RiskWhat Are the Ingredients in NOW Foods Magnesium Caps 400 mg?
Magnesium (elemental)
400 mg
Hypromellose (cellulose capsule)
Microcrystalline Cellulose
Stearic Acid (vegetable source)
Silicon Dioxide
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Dosage & Bioavailability
How the active doses and forms in Magnesium Caps 400 mg compare to the research.
•Magnesium (elemental) — 400 mg per serving is over the 350 mg/day upper limit (IOM (NIH ODS)).
Sources & References
Magnesium
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Magnesium 400 mg veg capsules
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The magic of magnesium
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Magnesium side effects 11703382
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Possible side effects of magnesium supplements en
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Magnesium supplements
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Types of magnesium supplements best use and benefits for your health
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Magnesium
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Www.nowfoods.com
Information from www.nowfoods.com
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Magnesium HealthProfessional
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Magnesium glycinate is this supplement helpful for you
Information from mcpress.mayoclinic.org
Frequently Asked Questions
Common questions about NOW Foods Magnesium Caps 400 mg