MagnesiumNHANES 2013 to 2016
About 48% of Americans
take in less magnesium than recommended from food and drink.
NIH Office of Dietary SupplementsMagnesium 400mg
Magnesium 400mg.
Strong for its niche
Magnesium is the lead active here, studied most for comfort after a heavy meal. 16 human studies on Magnesium back this formula, each one cited. Who it fits: for everyone, adults.
Full label disclosure
1Active ingredient16Human studies400 mgMagnesium
Verified by IngredientMDHow we read this product
- 01We read the label.
The panel on the left is the one we evaluated, line by line.
- 02Every active, separately.
All 1 actives checked against the clinical evidence: dose, form, and what the research actually shows.
- 03Then the formula as a whole.
Doses, ratios, and how the ingredients work together. That assessment is the verdict above: "Strong for its niche".
- 04Earned, not bought.
The verdict is public and identical whether or not a brand pays. A formula that does not clear the bar gets nothing.
Read by the engine against 2.1 million data points from clinical trials, PubMed and more than a hundred vetted sources. No individual reviewer is named or implied.
The receipts
16
Human studies
400 mg
Magnesium
400 mg per serving sits inside the studied 200 mg-400 mg range
Magnesium, NIH Office of Dietary Supplements + Rosanoff 2012 meta-analysis
Cross-checked against 42 documented interactions for these actives.
Read the evidenceMagnesium, the evidence →
Inside the formula
In context
The gap this formula speaks to.
Public health figures the engine matched to this formula's ingredients. Reported by their source, cited and dated, never written by the brand.
MagnesiumBRFSS 2014
More than 1 in 3 US adults
regularly sleep less than the recommended seven hours a night.
Peer-reviewed analysisThe people it speaks toFieldwork March 2022
24% of US adults
say digestive health is the most important aspect of their overall health, per a 2022 IFIC survey on gut health and probiotics.
International Food Information Council, 2022The people it speaks toFieldwork January 22 to 26, 2026
52% of US adults
believe common digestive symptoms such as bloating and abdominal pain are just a normal part of life, per a 2026 Harris Poll conducted for Oshi Health.
The Harris Poll for Oshi Health, 2026The people it speaks toFieldwork 2017 to 2018
58% of the recommended fiber intake
was reached on average by US consumers, who ate 8.1 grams of fiber per 1,000 calories in 2017 to 2018 versus the 14 grams recommended, per USDA Economic Research Service analysis of federal food consumption survey data.
USDA Economic Research Service, 2023The people it speaks toFieldwork March 28 to 29, 2023
40% of US adults
aged 18 and over report they experience bloating at least a few times a month, with 5% saying they experience it daily, per a 2023 Ipsos poll conducted for MDVIP.
Ipsos, 202311 more
34% of US adults
aged 18 and over report they experience abdominal discomfort or pain at least a few times per month, with women about twice as likely as men to report it several times weekly, per a 2023 Ipsos poll conducted for MDVIP.
Ipsos, 202328% of US adults
aged 18 and over say that digestive issues impact the quality of their life, a share that rises to about a third among those aged 18 to 44, per a 2023 Ipsos poll conducted for MDVIP.
Ipsos, 202332% of US adults
say they actively try to consume probiotics, and among them 60% try to do so at least once a day, per a 2022 IFIC survey on gut health.
International Food Information Council, 202259 to 66 days
was the median time it took adults to make a new daily health habit automatic across the studies a 2024 review pooled, with individuals ranging from 4 to 335 days.
Systematic review and meta-analysis, 202461% to 74%
About 61 to 74 percent of adults refilling a long-term medicine on their own stopped within a year, versus 33 to 44 percent on one set pickup day.
Cohort study, 2015Meta-analysis, 2016
Pooling 34 double-blind trials in 2,028 adults, magnesium at a median 368 mg a day for about 3 months lowered systolic blood pressure by about 2.0 mmHg and diastolic by about 1.8 mmHg on average.
The paperZhang et al., 2016PMID 27402922
Meta-analysis, 2025
Pooling randomised trials, magnesium supplementation lowered systolic blood pressure by a small amount, with the clearest shifts in adults whose readings started elevated.
The paperArgeros et al., 2025PMID 41000008
Meta-analysis, 2016
Across 18 double-blind trials, oral magnesium lowered fasting blood sugar in adults whose blood sugar ran high, and improved 2-hour glucose tolerance readings in adults at raised risk, at a small to moderate effect size with wide variation between trials.
European Journal of Clinical NutritionSystematic review, 2025
Across 23 trials in 1,345 adults with elevated blood sugar, magnesium raised blood magnesium, lowered fasting blood sugar by about 0.58 mmol/L, and only slightly moved longer-term blood sugar control.
Sultan Qaboos University Medical JournalSystematic review, 2025
Across studies in adults with clustered metabolic risk factors, longer-term magnesium intake was associated with lower levels of the blood marker C-reactive protein, a marker rather than an outcome.
Frontiers in nutritionWang et al., 2025 (Frontiers in nutrition)PMID 41245414
Randomised trial, 2021
In 90 adults with long-standing infrequent bowel movements, 1.5 g of magnesium oxide daily for 28 days improved symptoms in 68.3% versus 11.7% on placebo, with no severe events.
The American Journal of GastroenterologyPopulation figures from public health data. Context for the category, not a statement about any individual and not a claim about this product.
Every one of these is a fact the engine could ground.
Each line below was derived from this formula's own record at the time of verification. Nothing here was written by the brand, and nothing can be added that the evidence does not carry.
- Studied in people16 human studies on Magnesium back this formula, each one cited.
- A mechanism that is settledHow Magnesium works is settled pharmacology.
- Recent work on the recordThe most recent study on this record was published in 2021.
- Why this formatIt is a tablet, so the amount per serving is fixed and it stores well.
- The exact form, describedThe form on the label is Magnesium oxide, heavy. The record says what that form is and what it suits.
- Full label disclosureEvery ingredient on this label carries its own declared amount.
- Where it comes from and how it is madeMagnesium is made by mineral.
- Positions this formula already qualifies forThis formula already qualifies for positions beyond the one it is sold into, on the evidence it carries.
- A position nobody is holding yetSome of those positions are ones almost nobody is selling to yet.
How each ingredient usually behaves over time.
One ingredient, from its own page.
- MagnesiumWithin hours
Bowel effects can show within hours at larger single amounts. Moving blood and tissue magnesium takes weeks, and that part shows on a panel rather than as a feeling.
How each ingredient usually behaves over time, from its own page on IngredientMD. General timing for the ingredient, not a measurement of this product.
Chemical form
The same ingredient, carried differently.
What each form is, and where it fits in a formula. Measured findings carry the study that reported them.
- Magnesium oxide
Magnesium bound to oxygen. About 60 per cent of the molecule by weight is elemental magnesium, which is the highest share of the common forms and follows from the molecular weight rather than from any trial.
- Fits
- formulas where action in the gut is the intended effect, and tablets that need to carry a large elemental load in one unit
- Trade-off
- poorly soluble in water, which a 2025 review links to low bioavailability, though a 24-week head-to-head found plasma magnesium responses similar across the oxide, citrate and sulfate arms
Descriptions of the form itself, read from the cited studies. Not a comparison between products and not a statement about any individual.
Tablet
It is a tablet, so the amount per serving is fixed and it stores well.
Best forHigh-dose minerals and anything needing timed or delayed release.
Questions shoppers ask
- Is Magnesium 400mg independently verified?
- Yes. IngredientMD reviewed this formula independently and verified it in Oct 2026. The verdict is earned, not bought: brands can't edit or purchase it.
- What's in Magnesium 400mg?
- Magnesium 400mg is built on Magnesium. Each ingredient links to its own evidence page on IngredientMD.
- Were ingredient interactions checked?
- Yes. The combination was screened against 42 documented interactions for these actives in IngredientMD's interaction database.
- Who is IngredientMD?
- IngredientMD is an independent supplement-science platform. We analyze ingredients and formulas against clinical research, and we verify products only when they clear our bar. Labs run the tests. We review the results.
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These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This record is not medical advice. Always consult your healthcare provider before starting any supplement regimen.
Independent review by IngredientMD, not commissioned by Spring ValleyWork at Spring Valley? This verification is yours to claim →