A 400 mg magnesium oxide capsule delivers about 240 mg of elemental magnesium, because oxide runs close to 60 percent mineral by mass. That second figure is the one to compare across bottles. The 400 mg printed on the front is the compound, not the nutrient inside it.
One magnesium oxide row, two numbers, one mineral figure
Oxide is cheap to make and dense in mineral, so it packs a lot of the element into a small pill. A 400 mg capsule carrying 240 mg elemental weighs less than a quarter of an 1800 mg taurate serving that delivers roughly 130 to 145 mg. Density is the whole appeal here.
Oxide also dissolves less completely and draws water into the bowel, which is why it appears in laxative products and why some people stop after three days. If your aim is a steady daily intake with a quiet stomach, the cheap number is not automatically the right number. You're buying tolerance as much as milligram.
Convert the bottle into mineral before you compare
A bottle of 120 capsules at 400 mg holds 48,000 mg of compound. At 60 percent elemental, that's 28,800 mg of the mineral across 60 servings of two capsules. Write that number down before choosing between brands, since bottle counts hide the serving size.
Three products from this shop make the arithmetic plain. Taurate, 60 gummies, two a day at $25.99, works out to 87 cents a day for 30 days. Aged garlic extract, 90 gummies at two a day for $26.99, runs 45 days at 60 cents a day. Zinc carnosine, 120 capsules at two a day for $27.99, covers 60 days at 47 cents a day. Different weights, different supply lengths, and only one lines up with a calendar month.
What serving size does to the amount you swallow
Most oxide labels ask for one or two capsules daily. Check where the elemental figure sits, because some brands print 400 mg compound per capsule and 800 mg per serving, and doubling the serving doubles the mineral. The daily value is 420 mg for adult men and 310 to 320 mg for women, so a 240 mg serving covers a bit over half.
Here's how that goes wrong in a kitchen. Someone takes two capsules with dinner on a friend's advice, lands near 480 mg elemental without meaning to, and the next morning tells them what the label didn't. Start with one.
Read the elemental column, then the percent daily value beside it, then servings per container. Three numbers in that order, and the compound weight stops being the headline.
Where this form stops being the sensible buy
Oxide is a fine way to buy mineral on a budget and a poor fit for anyone whose gut objects. Chelated forms cost more per milligram and sit differently for many people. Neither is better in the abstract. Your wallet and your stomach each get a vote.
A capsule label can give compound weight, elemental weight, form and count. It can't tell you how much you absorb on an empty stomach, and it can't tell you whether your intake was low to begin with. That part needs a blood test and a clinician, not a shopping page.
Velna Zivs prints both figures on the panel and ships from the United States within one business day, with standard delivery at 3 to 7 business days. Orders over the free shipping threshold in the cart skip the charge, and returns run 30 days from delivery. If a panel shows only the salt weight, ask for the elemental row before buying. A brand that can't quote the second number is telling you something.
Frequently asked questions
How many milligrams should I look for?Show answerHide answer
Look for about 240 mg of elemental magnesium from a 400 mg oxide capsule, not the compound weight.
Does a bigger number mean a stronger product?Show answerHide answer
Not always. A 400 mg oxide capsule can deliver less mineral than a well dosed chelate serving.
Where is the elemental figure printed?Show answerHide answer
It sits on the Supplement Facts row, per serving, beside the percent daily value.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
