NOW Foods Supplements, Magnesium Oxide, Enzyme Function, Nervous System Support, 8-Ounce

Brand: NOW
Category: Diet & Sports Nutrition
Recorded price: $10.40; 6 Sep 2026
Price per serving: $0.02

Supplement facts

Serving size: 0.25 tsp
Servings per container: 454

Ingredient	Amount per serving	% daily value
Magnesium	290 mg	69%

Other ingredients

None

Directions on the label

Suggested Usage: Mix 1/4 level teaspoon of powder into at least 6 oz. of cold water or clear liquid. Take once daily with a meal. Pure Magnesium Oxide Powder can increase the temperature of liquids upon contact; therefore, the recommended serving must be mixed into at least 6 oz. of cold liquid to neutralize this reaction prior to ingestion.

Label data from the Dietary Supplement Label Database.

Label data as of 10 Sep 2026

Product score

80 / 100Very good

Category average: 73 / 100
Average for similar products: 80 / 100

This jar provides a reasonable daily magnesium amount, but magnesium oxide is a less preferable form for absorption and gastrointestinal tolerability than more soluble alternatives.

Scoring criteria

Quantity
100 / 100
The labelled 290 mg of elemental magnesium once daily is a reasonable maintenance amount for general adult supplementation.
Form
60 / 100
Magnesium oxide is an established but comparatively less soluble form with greater potential for gastrointestinal laxative effects than better-tolerated soluble magnesium forms.
Convenience
100 / 100
The label directs one measured quarter-teaspoon portion once daily with a meal, and the container provides 454 servings.
Label accuracy
100 / 100
The high-confidence matched label clearly states 290 mg of magnesium per quarter-teaspoon serving and contains no contradictory amount.
Purity
75 / 100
The label lists no additional ingredients, but no product-specific testing or certification evidence is supplied to support a higher purity mark.
Cofactors
0 / 100
No meaningful complementary cofactor is declared because the product contains only magnesium oxide.