NEW
🅱️ B-Complex
Cost per serving
$0.17
mineral · 167 active deals
The best-value Magnesium right now is about $0.05 per dose — across 162 tracked products the median is $0.124/dose, so shopping on cost-per-dose can cut your cost several-fold. Every Magnesium deal here is ranked by cost per dose— what you actually pay per serving, not the sticker price — because forms and absorption differ, so the cheapest bottle isn’t always the cheapest dose.
Right now the best value across our full Magnesium catalog is at $0.05 per serving.
Recommended daily intake
The 350 mg upper limit applies to magnesium from SUPPLEMENTS only, not food; exceeding it commonly causes loose stools. General FDA/NIH adult guidance — not medical advice.
Magnesium is an abundant mineral that acts as a cofactor in more than 300 enzyme systems regulating diverse biochemical reactions, including protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation; it is also required for energy production, contributes to the structural development of bone, and is needed for the synthesis of DNA, RNA, and the antioxidant glutathione. It also plays a role in moving calcium and potassium ions across cell membranes, a process important for nerve impulse conduction, muscle contraction, and normal heart rhythm. It has been studied in relation to hypertension and cardiovascular disease, type 2 diabetes, osteoporosis, and migraine headaches; for example, clinical trials suggest magnesium supplementation only marginally lowers blood pressure, observational studies link higher intakes with lower diabetes risk while clinical trial results are conflicting, and the American Academy of Neurology and American Headache Society have concluded magnesium therapy is probably effective for migraine prevention, though for most of these conditions NIH notes the evidence is limited, inconsistent, or that more research is needed. — per the NIH Office of Dietary Supplements; not medical advice.
Magnesium supplements are available in a variety of forms, including magnesium oxide, citrate, and chloride, and the Supplement Facts label declares the amount of elemental magnesium rather than the weight of the whole compound. The absorption of these forms varies, with forms that dissolve well in liquid being more completely absorbed in the gut than less soluble forms. The fact sheet notes that small studies have found the aspartate, citrate, lactate, and chloride forms are absorbed more completely and are more bioavailable than magnesium oxide and magnesium sulfate.
A supplement's front-label figure is usually the compound weight, not elemental magnesium. By weight, magnesium oxide is about 60% elemental while orotate is only about 7% — so a “1,000 mg orotate” capsule delivers roughly 70 mg of elemental magnesium. Always compare the “Magnesium” line in the Supplement Facts panel, not the number on the front of the bottle.
| magnesium form |
|---|
Every Magnesium deal above is ranked by real cost per dose with no paid placement — see our and .
RDAs depend on age and sex. Adult men need 400-420 mg; adult women need 310-320 mg. Pregnancy is 350-400 mg and lactation 310-360 mg. Children range from 80 mg (1-3 years) to 240 mg (9-13 years); infants have AIs of 30-75 mg. — per the NIH Office of Dietary Supplements; general information, not medical advice.
Yes. The for supplemental magnesium is 350 mg for adults. High supplement or medication doses can cause diarrhea, nausea, and abdominal cramping. Very high doses cause toxicity: hypotension, vomiting, difficulty breathing, irregular heartbeat, and cardiac arrest; fatal hypermagnesemia has occurred. — per the NIH Office of Dietary Supplements; general information, not medical advice.
Early signs include loss of appetite, nausea, vomiting, fatigue, and weakness. As it worsens: numbness, tingling, muscle contractions and cramps, seizures, personality changes, abnormal heart rhythms, and coronary spasms. Severe deficiency can cause hypocalcemia (low calcium) or hypokalemia (low potassium). — per the NIH Office of Dietary Supplements; general information, not medical advice.
Groups at risk of inadequacy include people with gastrointestinal diseases (Crohn's, celiac, regional enteritis), people with type 2 diabetes, people with alcohol dependence, and older adults, who have lower intakes, reduced gut absorption, and increased renal excretion. — per the NIH Office of Dietary Supplements; general information, not medical advice.
We link primary sources and paraphrase their findings — never copy their text, tables, or images. Cost-per-dose figures are our own first-party catalog data.
| ~% elemental |
|---|
| elemental mg per 1,000 mg |
|---|
| magnesium oxide | ~60% | ~600 mg |
| magnesium carbonate | ~29% | ~290 mg |
| magnesium citrate | ~16% | ~160 mg |
| magnesium malate | ~15% | ~150 mg |
| magnesium glycinate | ~14% | ~140 mg |
| magnesium bisglycinate | ~14% | ~140 mg |
| magnesium lactate | ~12% | ~120 mg |
| magnesium chloride | ~12% | ~120 mg |
| magnesium sulfate | ~10% | ~100 mg |
| magnesium taurate | ~9% | ~90 mg |
| magnesium threonate | ~8% | ~80 mg |
| magnesium orotate | ~7% | ~70 mg |
Elemental fractions are from standard molecular weights (rounded); real products vary by hydration and formulation — verify on the Supplement Facts panel.
Magnesium is widely distributed in plant and animal foods and in beverages, with green leafy vegetables (e.g., spinach), legumes, nuts, seeds, and whole grains being good sources; in general, foods that contain dietary fiber provide magnesium, and it is also added to some fortified breakfast cereals. Among the richest selected foods listed are roasted pumpkin seeds (156 mg per ounce, 37% DV), chia seeds (111 mg per ounce), dry-roasted almonds (80 mg per ounce), and boiled spinach (78 mg per half cup) — per the NIH Office of Dietary Supplements.
Groups more likely to be at risk of magnesium inadequacy include people with gastrointestinal diseases (such as Crohn's disease and celiac disease), people with type 2 diabetes, people with alcohol dependence, and older adults. Early signs and symptoms of deficiency include loss of appetite, nausea, vomiting, fatigue, and weakness; as it worsens, numbness, tingling, muscle contractions and cramps, seizures, personality changes, abnormal heart rhythms, and coronary spasms can occur, and severe deficiency can cause hypocalcemia or hypokalemia — per the NIH Office of Dietary Supplements.
Too much magnesium from food does not pose a health risk in healthy individuals because the kidneys eliminate excess amounts, but high doses from dietary supplements or medications often cause diarrhea, nausea, and abdominal cramping. The Tolerable Upper Intake Level (UL) for supplemental magnesium is 350 mg/day for adults — per the NIH Office of Dietary Supplements.
Cost per serving
$0.17
Cost per serving
$0.23
Pricey120 servings · ~120-day supply
Cost per serving
$0.32
Pricey60 servings · ~60-day supply
Cost per serving
$0.08
250 servings · ~250-day supply
Cost per serving
$0.37
90 servings · ~90-day supply
Cost per serving
$0.23
120 servings · ~120-day supply
Cost per serving
$0.21
120 servings · ~120-day supply
Cost per serving
$1.59
22 servings · ~22-day supply
Cost per serving
$0.48
60 servings · ~60-day supply
Cost per serving
$0.37
PriceyCost per serving
$0.38
60 servings · ~60-day supply
Cost per serving
$0.44
60 servings · ~60-day supply
Cost per serving
$0.28
Pricey60 servings · ~60-day supply
Cost per serving
$0.50
60 servings · ~60-day supply
Cost per serving
$0.45
60 servings · ~60-day supply
Cost per serving
$0.36
60 servings · ~60-day supply
Cost per serving
$0.11
Avg·−63%180 servings · ~180-day supply
Cost per serving
$0.12
Avg·−54%60 servings · ~60-day supply
Cost per serving
$0.07
Cheap·−79%240 servings · ~240-day supply
Cost per serving
$0.19
Avg·−31%90 servings · ~90-day supply
Cost per serving
$0.12
Avg·−50%180 servings · ~180-day supply
Cost per serving
$0.06
Cheap·−83%420 servings · ~420-day supply
Cost per serving
$0.09
Cheap·−75%180 servings · ~180-day supply
Cost per serving
$0.08
Cheap·−77%200 servings · ~200-day supply
Cost per serving
$0.07
Cheap·−79%120 servings · ~120-day supply
Cost per serving
$0.39
Pricey60 servings · ~60-day supply
Cost per serving
$0.05
Cheap·−85%100 servings · ~100-day supply
Cost per serving
$0.06
Cheap·−83%100 servings · ~100-day supply
Cost per serving
$0.20
Avg·−30%60 servings · ~60-day supply
Cost per serving
$0.12
Avg·−50%90 servings · ~90-day supply
Cost per serving
$0.09
Cheap·−75%90 servings · ~90-day supply
Cost per serving
$0.09
Cheap·−75%100 servings · ~100-day supply
Cost per serving
$0.10
Avg·−66%180 servings · ~180-day supply
Cost per serving
$0.11
Avg·−57%100 servings · ~100-day supply
Cost per serving
$0.08
Cheap·−77%100 servings · ~100-day supply
Cost per serving
$0.13
Avg·−49%100 servings · ~100-day supply
Cost per serving
$0.33
Pricey180 servings · ~180-day supply
Cost per serving
$0.17
Avg·−39%180 servings · ~180-day supply
Cost per serving
$0.11
90 servings · ~90-day supply
Cost per serving
$0.11
240 servings · ~240-day supply
Cost per serving
$0.05
250 servings · ~250-day supply
Cost per serving
$0.10
250 servings · ~250-day supply
Cost per serving
$0.13
100 servings · ~100-day supply
Cost per serving
$0.10
Avg·−70%360 servings · ~360-day supply
Cost per serving
$0.19
Avg·−33%120 servings · ~120-day supply
Cost per serving
$0.20
Avg100 servings · ~100-day supply
Cost per serving
$0.10
250 servings · ~250-day supply
Cost per serving
$0.07
Cheap·−79%90 servings · ~90-day supply
Amazon.com · 🅱️ B-Complex
CPS
Price
$9.99
Amazon.com · 🌙 Magnesium
CPS
Price
$27.39
Amazon.com · 🌙 Magnesium
CPS
Price
$18.99
Amazon.com · 🦴 Calcium
CPS
Price
$19.99
Amazon.com · 🦴 Calcium
CPS
Price
$32.95
Amazon.com · 🅱️ B-Complex
CPS
Price
$27.49
Amazon.com · 🅱️ B-Complex
CPS
Price
$24.99
Amazon.com · 🌿 Ashwagandha KSM-66
CPS
Price
$34.99
Amazon.com · 🫀 CoQ10
CPS
Price
$28.98
Amazon.com · 🌙 Magnesium
CPS
Price
$21.99
Amazon.com · 🅱️ B-Complex
CPS
Price
$22.99
Amazon.com · 🦴 Calcium
CPS
Price
$26.49
Amazon.com · 🌙 Magnesium
CPS
Price
$16.89
Amazon.com · 🦴 Calcium
CPS
Price
$29.89
Amazon.com · 🫀 CoQ10
CPS
Price
$26.72
Amazon.com · 🫀 CoQ10
CPS
Price
$21.49
Amazon.com · 🌙 Magnesium
CPS
Price
$18.95
Amazon.com · 🌙 Magnesium
CPS
Price
$7.10
Amazon.com · 🌙 Magnesium
CPS
Price
$17.81
Amazon.com · 🌙 Magnesium
CPS
Price
$17.39
Amazon.com · 🌙 Magnesium
CPS
Price
$22.29
Amazon.com · 🌙 Magnesium
CPS
Price
$24.95
Amazon.com · 🌙 Magnesium
CPS
Price
$15.91
Amazon.com · 🌙 Magnesium
CPS
Price
$16.06
Amazon.com · 🌙 Magnesium
CPS
Price
$8.90
Amazon.com · 🌙 Magnesium
CPS
Price
$23.22
HerbsPro · 🌙 Magnesium
CPS
Price
$5.25
HerbsPro · 🌙 Magnesium
CPS
Price
$5.95
HerbsPro · 🌙 Magnesium
CPS
Price
$11.89
HerbsPro · 🌙 Magnesium
CPS
Price
$11.19
HerbsPro · 🌙 Magnesium
CPS
Price
$7.95
HerbsPro · 🌙 Magnesium
CPS
Price
$8.75
HerbsPro · 🌙 Magnesium
CPS
Price
$18.20
HerbsPro · 🌙 Magnesium
CPS
Price
$11.36
HerbsPro · 🌙 Magnesium
CPS
Price
$8.28
HerbsPro · 🌙 Magnesium
CPS
Price
$12.91
HerbsPro · 🌙 Magnesium
CPS
Price
$60.19
HerbsPro · 🌙 Magnesium
CPS
Price
$29.99
HerbsPro · 🦴 Calcium
CPS
Price
$9.79
HerbsPro · 🦴 Calcium
CPS
Price
$27.29
HerbsPro · 🦴 Calcium
CPS
Price
$12.18
HerbsPro · 🦴 Calcium
CPS
Price
$24.09
HerbsPro · 🦴 Calcium
CPS
Price
$12.59
HerbsPro · 🌙 Magnesium
CPS
Price
$34.65
HerbsPro · 🌙 Magnesium
CPS
Price
$22.39
HerbsPro · 🌙 Magnesium
CPS
Price
$20.49
HerbsPro · 🦴 Calcium
CPS
Price
$24.59
HerbsPro · 🌙 Magnesium
CPS
Price
$6.68
Yes. Magnesium can reduce absorption of oral bisphosphonates and form insoluble complexes with tetracycline and quinolone antibiotics; separate doses by hours. Loop and thiazide diuretics increase magnesium loss, while potassium-sparing diuretics reduce excretion. Long-term proton pump inhibitors can cause low magnesium levels. — per the NIH Office of Dietary Supplements; general information, not medical advice.
Nutricost, Magnesium Oxide Capsules, 375 Mg, 240 Count at $0.05 per serving — the lowest cost-per-dose magnesium in our catalog. See the full ranking on the Best Magnesium page.
We're tracking 167 active Magnesium deals across Amazon US and partner retailers, ranked by community votes and cost-per-dose — not paid placement.
Across 162 tracked Magnesium deals the median cost-per-dose is $0.124; the cheapest quartile comes in under $0.089 per serving. Anything below the median is a solid deal for the same molecule.
Deals are submitted by the community and ranked by net votes (hot minus cold) plus cost-per-dose normalised across container sizes. We take no affiliate kickbacks for ordering; sponsored slots, when present, are clearly badged.
Too much magnesium from food does not pose a health risk in healthy individuals because the kidneys eliminate excess amounts, but high doses from dietary supplements or medications often cause diarrhea, nausea, and abdominal cramping. The Tolerable Upper Intake Level (UL) for supplemental magnesium is 350 mg/day for adults — per the NIH Office of Dietary Supplements.
Magnesium is widely distributed in plant and animal foods and in beverages, with green leafy vegetables (e.g., spinach), legumes, nuts, seeds, and whole grains being good sources; in general, foods that contain dietary fiber provide magnesium, and it is also added to some fortified breakfast cereals. Among the richest selected foods listed are roasted pumpkin seeds (156 mg per ounce, 37% DV), chia seeds (111 mg per ounce), dry-roasted almonds (80 mg per ounce), and boiled spinach (78 mg per half cup) — per the NIH Office of Dietary Supplements.
Labels often show the magnesium COMPOUND weight, not elemental magnesium. By weight, magnesium oxide is about 60% elemental while orotate is only about 7% — so a "1,000 mg orotate" product delivers roughly 70 mg of elemental magnesium. Compare the "Magnesium" line in the Supplement Facts panel, not the front-of-bottle number.
Dosage, upper-limit, deficiency, food-source and interaction facts are sourced from the NIH Office of Dietary Supplements Magnesium fact sheet. General information, not medical advice.
60 servings · ~60-day supply
60 servings · ~60-day supply
