Cheapest Magnesium (as magnesium oxide and magnesium glycinate) on iHerb
Ranked by real cost per 100 mg of Magnesium (as magnesium oxide and magnesium glycinate) — cheapest value first.
Prices updated Jul 25, 2026 · 22 products · Prices in USD
| # | Product | Dose | Price (USD) | Cost per 100 mg | |
|---|---|---|---|---|---|
| 1 |  | 42 mg | 2.00 | 0.053 | View on iHerb → |
| 2 |  | 350 mg | 11.95 | 0.114 | View on iHerb → |
| 3 |  | 400 mg | 66.70 | 0.185 | View on iHerb → |
| 4 |  | 400 mg | 67.70 | 0.188 | View on iHerb → |
| 5 |  | 210 mg | 24.10 | 0.191 | View on iHerb → |
| 6 |  | 210 mg | 26.31 | 0.209 | View on iHerb → |
| 7 |  | 300 mg | 45.71 | 0.254 | View on iHerb → |
| 8 |  | 400 mg | 30.75 | 0.256 | View on iHerb → |
| 9 |  | 300 mg | 14.11 | 0.314 | View on iHerb → |
| 10 |  | 210 mg | 36.56 | 0.435 | View on iHerb → |
| 11 |  | 210 mg | 36.56 | 0.435 | View on iHerb → |
| 12 |  | 42 mg | 17.55 | 0.464 | View on iHerb → |
| 13 |  | 42 mg | 17.60 | 0.466 | View on iHerb → |
| 14 |  | 210 mg | 14.71 | 0.467 | View on iHerb → |
| 15 |  | 42 mg | 17.69 | 0.468 | View on iHerb → |
| 16 |  | 42 mg | 17.77 | 0.470 | View on iHerb → |
| 17 |  | 42 mg | 18.10 | 0.479 | View on iHerb → |
| 18 |  | 100 mg | 31.04 | 0.517 | View on iHerb → |
| 19 |  | 40 mg | 20.31 | 0.564 | View on iHerb → |
| 20 |  | 105 mg | 31.64 | 0.753 | View on iHerb → |
| 21 |  | 21 mg | 20.19 | 1.07 | View on iHerb → |
| 22 |  | 21 mg | 20.33 | 1.08 | View on iHerb → |
- 1Cost per 100 mg 0.053
- Dose
- 42 mg
- Servings
- 90
- Price (USD)
- 2.00
- 2Cost per 100 mg 0.114
- Dose
- 350 mg
- Servings
- 30
- Price (USD)
- 11.95
- 3Cost per 100 mg 0.185
- Dose
- 400 mg
- Servings
- 90
- Price (USD)
- 66.70
- 4Cost per 100 mg 0.188
- Dose
- 400 mg
- Servings
- 90
- Price (USD)
- 67.70
- 5Cost per 100 mg 0.191
- Dose
- 210 mg
- Servings
- 60
- Price (USD)
- 24.10
- 6Cost per 100 mg 0.209
- Dose
- 210 mg
- Servings
- 60
- Price (USD)
- 26.31
- 7Cost per 100 mg 0.254
- Dose
- 300 mg
- Servings
- 60
- Price (USD)
- 45.71
- 8Cost per 100 mg 0.256
- Dose
- 400 mg
- Servings
- 30
- Price (USD)
- 30.75
- 9Cost per 100 mg 0.314
- Dose
- 300 mg
- Servings
- 15
- Price (USD)
- 14.11
- 10Cost per 100 mg 0.435
- Dose
- 210 mg
- Servings
- 40
- Price (USD)
- 36.56
- 11Cost per 100 mg 0.435
- Dose
- 210 mg
- Servings
- 40
- Price (USD)
- 36.56
- 12Cost per 100 mg 0.464
- Dose
- 42 mg
- Servings
- 90
- Price (USD)
- 17.55
- 13Cost per 100 mg 0.466
- Dose
- 42 mg
- Servings
- 90
- Price (USD)
- 17.60
- 14Cost per 100 mg 0.467
- Dose
- 210 mg
- Servings
- 15
- Price (USD)
- 14.71
- 15Cost per 100 mg 0.468
- Dose
- 42 mg
- Servings
- 90
- Price (USD)
- 17.69
- 16Cost per 100 mg 0.470
- Dose
- 42 mg
- Servings
- 90
- Price (USD)
- 17.77
- 17Cost per 100 mg 0.479
- Dose
- 42 mg
- Servings
- 90
- Price (USD)
- 18.10
- 18Cost per 100 mg 0.517
- Dose
- 100 mg
- Servings
- 60
- Price (USD)
- 31.04
- 19Cost per 100 mg 0.564
- Dose
- 40 mg
- Servings
- 90
- Price (USD)
- 20.31
- 20Cost per 100 mg 0.753
- Dose
- 105 mg
- Servings
- 40
- Price (USD)
- 31.64
- 21Cost per 100 mg 1.07
- Dose
- 21 mg
- Servings
- 90
- Price (USD)
- 20.19
- 22Cost per 100 mg 1.08
- Dose
- 21 mg
- Servings
- 90
- Price (USD)
- 20.33
How we rank Magnesium (as magnesium oxide and magnesium glycinate)
Two supplements can list the same dose per serving yet cost very differently once you account for how many servings are in the bottle. We calculate the total nutrient in each container (dose per serving × servings per container), divide the current price by that total, and rank by the resulting cost per unit. Lower is better. Because prices are refreshed automatically, this ranking reflects today's iHerb pricing rather than a snapshot from months ago.
Cost per unit is a starting point, not the whole story — the ideal form, third-party testing, and other ingredients matter too. Always check the label and consult a healthcare professional before starting a supplement.
Prices update automatically and may differ from iHerb at checkout. Rankings are based on cost per unit of the listed nutrient and are for informational purposes only — not medical advice. Links to iHerb are affiliate links.