Lower cost per 100 mg elemental magnesium
See how the ingredients, value and convenience compare with offers available in United States.
Lower cost per 100 mg elemental magnesium
Higher declared elemental magnesium per label serving
Lower maximum capsule count across the label-directed day
All prices use USD. Tax inclusion is shown when known; shipping is excluded unless the selected retailer explicitly includes it.
| Fact | Magnesium 250 mg, 250 Tablets21st Century | Magnesium (Citrate) 100 mg, 100 Vegetarian CapsulesLife Extension |
|---|---|---|
| Shared product and offer facts | ||
| Brand | 21st Century | Life Extension |
| Current container price | $7.99 | $9.50 |
| Label serving size | 1 tablet | 1 vegetarian capsule |
| Servings per container | 250 | 100 |
| Delivery form | Tablet | Capsule |
| Availability | In stock | In stock |
| Selected retailer | iHerb | iHerb |
| Product last verified | Jul 17, 2026 | Jul 17, 2026 |
| Tax included | Not confirmed | Not confirmed |
| Shipping included | No — excluded from comparison | No — excluded from comparison |
| Magnesium-specific facts | ||
| Elemental magnesium | 250 mg | 100 mg |
| Magnesium form | Magnesium oxide | Magnesium citrate |
| Cost / 100 mg | $0.01 | $0.10 |
Daily values multiply one label serving by the manufacturer’s stated frequency and preserve ranges. Total magnesium compound is separate from elemental magnesium; total fish or algae oil is separate from EPA plus DHA.