Magnesium citrate per serving comes down to one conversion: the salt is roughly 16 percent of the mineral by weight, so a 500 mg capsule of magnesium citrate supplies about 80 mg. If the label says 500 mg and you assumed 500 mg of the nutrient, you're off by a factor of six.
Magnesium citrate is the salt, not the mineral
Citrate here means the mineral bound to citric acid. The bound weight includes the acid, which your body handles like any other citrate and which does nothing for the figure you came for. Only the element fraction counts. At 16 percent, a 400 mg dose gives you 64 mg, a 500 mg dose gives you 80 mg, and a 1000 mg dose gives you 160 mg.
This is why two bottles can say "magnesium citrate 500 mg" and deliver wildly different amounts. One manufacturer may print the salt weight, another the element weight, and the front label rarely tells you which. The Supplement Facts panel does, because it must list the nutrient as its own row with a daily value beside it.
How the forms compare at equal weights
Oxide is about 60 percent of the mineral, so 400 mg of the compound yields roughly 240 mg. Glycinate runs near 14 percent. Taurate sits lower again. A serving of three capsules is common for glycinate and citrate products because the element weight per capsule is small.
Our citrate ships as 120 capsules at $17.99, and the panel states 80 mg per capsule from 500 mg of the salt. Three capsules gives 240 mg, which is 57 percent of the 420 mg daily value for adults. That leaves room for food sources without pushing past the 350 mg supplemental upper limit that applies to most adults.
Cost per milligram, not per pill
Run the same division you'd run on any grocery item. At $17.99 for 120 with 80 mg each, the cost is 15 cents per pill and about 0.19 cents per milligram. A 240 count bottle at $29.99 brings that to 12.5 cents and 0.156 cents per milligram. The larger bottle is better value by roughly 18 percent, and both figures assume three a day rather than one.
One a day is a common mistake with citrate. People buy a 120 count, take one daily, and finish the container in four months at 80 mg, which is under a fifth of the daily value. If 80 mg is your target, one is correct. If you're aiming for 200 mg or more, budget for the count rather than the price.
Where citrate earns its place, and where it does not
Citrate absorbs well and costs less than glycinate, which makes it the default for a daily routine. Its known drawback is digestive: citrate draws water into the bowel, and at 300 mg or more in a single sitting a fair number of people notice looser stools within a few hours. Splitting the dose across the day, or taking it with a meal, reduces that for most.
If your gut is sensitive, glycinate is the better fit even at a higher cost. If you take a proton pump inhibitor or have reduced stomach acid, oxide is a poor bet because it needs acid to dissolve. Those are limits worth knowing before you order a multipack.
Keeping the label honest at checkout
Subscriptions on a 120 count at three a day run out in 40 days, not 30, so a monthly auto-ship will slowly build a surplus in your cupboard. Set the interval to six weeks or buy the 240 count and reorder every 80 days. Shipping thresholds matter too: a single bottle often falls under the free-shipping line, and adding a second to clear it can cost less than the postage on one.
Check the element row once, write the per-capsule figure on the bottle with a marker, and the arithmetic stops being a monthly chore.
Common questions
How many milligrams should I look for? Read the element row on the panel, not the compound weight, and compare it with the 420 mg daily value.
Does a bigger front-label number mean a stronger product? Not always. A larger compound weight can deliver less of the nutrient itself.
Where is the element figure printed? On the Supplement Facts panel, listed per serving beside the percent daily value.
Frequently asked questions
How many milligrams should I look for?Show answerHide answer
Read the nutrient line, not the compound weight, and compare it with the daily value.
Does a bigger number mean a stronger product?Show answerHide answer
Not always. A larger compound weight can deliver less of the nutrient itself.
Where is this printed?Show answerHide answer
On the Supplement Facts panel, listed per serving.
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.
