Get Started Free

Cheapest Magnesium (as magnesium phosphate) on iHerb

Ranked by real cost per 10 mg of Magnesium (as magnesium phosphate) — cheapest value first.

Prices updated Jul 25, 2026 · 9 products · Prices in USD

The priciest option here costs about 10.6× more per 10 mg of Magnesium (as magnesium phosphate) than the best-value pick MAV Nutrition. For the same daily dose, choosing by cost per unit instead of sticker price can meaningfully cut your yearly spend.
#ProductDoseServingsPrice (USD)Cost per 10 mg
1
MAV Nutrition, Calming Magnesium Gummies, For Kids, Yummy Strawberry, 60 Gummies
MAV Nutrition, Calming Magnesium Gummies, For Kids, Yummy Strawberry, 60 Gummies
MAV Nutrition
100 mg3016.490.055View on iHerb →
2
Optimum Nutrition, Serious Mass™, Chocolate, 6 lb (2.72 kg)
Optimum Nutrition, Serious Mass™, Chocolate, 6 lb (2.72 kg)
Optimum Nutrition
200 mg857.020.356View on iHerb →
3
Optimum Nutrition, Serious Mass™, Chocolate Peanut Butter, 6 lb (2.72 kg)
Optimum Nutrition, Serious Mass™, Chocolate Peanut Butter, 6 lb (2.72 kg)
Optimum Nutrition
195 mg857.020.366View on iHerb →
4
Optimum Nutrition, Serious Mass™, Vanilla, 6 lb (2.72 kg)
Optimum Nutrition, Serious Mass™, Vanilla, 6 lb (2.72 kg)
Optimum Nutrition
140 mg857.020.509View on iHerb →
5
EFX Sports, Karbolyn® Hydrate, White Cherry Frost, 4 lb 1.5 oz (1,856 g)
EFX Sports, Karbolyn® Hydrate, White Cherry Frost, 4 lb 1.5 oz (1,856 g)
EFX Sports
13 mg6744.990.517View on iHerb →
6
EFX Sports, Karbolyn® Hydrate, Watermelon Wave, 4 lb 1.5 oz (1,856 g)
EFX Sports, Karbolyn® Hydrate, Watermelon Wave, 4 lb 1.5 oz (1,856 g)
EFX Sports
13 mg6644.990.524View on iHerb →
7
EFX Sports, Karbolyn® Hydrate, Lemon Lime, 4 lb 1.5 oz (1,856 g)
EFX Sports, Karbolyn® Hydrate, Lemon Lime, 4 lb 1.5 oz (1,856 g)
EFX Sports
13 mg6444.990.541View on iHerb →
8
Isatori, Amino-Gro, Frosted Lemonade, 10.6 oz (300 g)
Isatori, Amino-Gro, Frosted Lemonade, 10.6 oz (300 g)
Isatori
15 mg3024.990.555View on iHerb →
9
Optimum Nutrition, Serious Mass™, Strawberry, 6 lb (2.72 kg)
Optimum Nutrition, Serious Mass™, Strawberry, 6 lb (2.72 kg)
Optimum Nutrition
140 mg865.380.584View on iHerb →

How we rank Magnesium (as magnesium phosphate)

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.

← Browse all nutrients

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.