Magnesium citrate: three labels, side by side

Start with the exact bottle

This comparison covers three specific U.S. products: Nature Made Magnesium Citrate 250 mg, 60 softgels; NOW Magnesium Citrate, 120 veg capsules; and Life Extension Magnesium Citrate 100 mg, 100 capsules. A different bottle count, format, or formula can change the calculation. Check the selection at the retailer before buying.

We read manufacturer product pages and labels. We have not tested these products in a laboratory, independently measured their contents, or assessed their effectiveness in people. The order below is not a ranking. A smaller price per serving does not mean a product is a better choice for your health.

Three serving sizes, three different comparisons

Nature Made lists two softgels per serving with 250 mg of magnesium. That works out to 125 mg per softgel and 30 labeled servings in the 60-softgel bottle. NOW lists three capsules per serving with 400 mg, which is approximately 133 mg per capsule and 40 servings in a 120-capsule bottle. Life Extension lists one capsule with 100 mg, giving 100 labeled servings per bottle.

Those figures describe elemental magnesium, the amount of the mineral itself listed in Supplement Facts. They are not the total weight of the citrate compound. The serving-size switch below makes the arithmetic visible; it does not suggest that you change the manufacturer’s directions.

• Nature Made: softgel format; read the other ingredients for gelatin and other ingredients relevant to you.
• NOW: veg-capsule format; check the current label for dietary suitability and allergen information.
• Life Extension: directions allow one capsule one to three times daily; a bottle containing 100 one-capsule servings is not automatically a 100-day supply.

Price per serving needs context

At the prices recorded on October 4, 2026, the one-time bottle prices were $14.19, $19.99, and $9.50 respectively. Our calculations exclude delivery, sales tax, coupons, subscriptions, and quantity discounts. They are a dated snapshot, not a live price feed.

The products provide different amounts of magnesium per serving, so the displayed serving costs are not dose-equivalent comparisons. Compare the labeled amount and format first. Then use the cost calculator with the actual price you see at checkout. Avoid increasing a serving simply to make two products appear equivalent.

Check the safety context before choosing

The NIH lists an adult upper limit of 350 mg a day of magnesium from supplements and medicines, unless a health professional advises otherwise. Magnesium in food does not count toward that limit. NOW’s labeled 400 mg serving exceeds that general adult supplemental limit; it is not a default starting amount.

Magnesium can cause diarrhea, nausea, or cramping and can interfere with some medicines. Kidney disease makes a clinician’s advice especially important. A supplement comparison cannot determine whether you need magnesium or what amount is appropriate. Bring the complete label and your medication list to your own clinician or pharmacist.

How to use this comparison

Shortlist a format you can use, check the labeled serving against professional advice, and confirm the exact bottle and other ingredients. Only then compare the delivered price. If your clinician suggested a particular amount, show them the actual label rather than substituting a front-of-bottle number.

The next useful step is not necessarily a purchase. Our label checklist gives you a compact list of details to check, and our ingredient guide explains how magnesium from food, supplements, and medicines fits together.