Magnesium explained: what it is and side effects
Magnesium comes from plant and animal foods and drinks, and the NIH says this nutrient plays a part in muscle and nerve function. Adults 19 and older need 400 to 420 mg daily for men and 310 to 320 mg for women. Four products we reviewed list magnesium, and all four labels print 1 mg to 125 mg per serving.
- What it is
- Mineral
- What adults need a day (ages 19 and older)
- 400 to 420 mg for men, 310 to 320 mg for women
- Upper limit
- 350 mg from supplements and medicines
- In the products we reviewed
- 4, every label prints the amount
What magnesium is
- Magnesium comes from many plant and animal foods and from drinks.2
- Magnesium is a nutrient that the body needs to stay healthy.1
- Magnesium plays a part in many body processes, including muscle and nerve function.1
- Magnesium is a cofactor in more than 300 enzyme systems in the body.2
- Magnesium helps build bone structure and is needed to make DNA, RNA and the antioxidant glutathione.2
- Magnesium aspartate, citrate, lactate and chloride tend to be absorbed better than magnesium oxide and magnesium sulfate.2
Foods that have it2
- Pumpkin seeds
- Chia seeds
- Almonds
- Spinach
- Cashews
- Peanuts
- Shredded wheat cereal
- Soymilk
Works with
- Vitamin D. Magnesium affects the body's levels of the active form of vitamin D.2
How much magnesium each product gives
Adults need 310 to 420 mg a day
Before you take it
If you take medicines
- Bisphosphonates such as alendronate (osteoporosis medicines)
- Magnesium can lower how well the body absorbs these medicines, and taking them at least 2 hours apart can limit this.2
- Tetracycline and quinolone antibiotics, such as doxycycline and ciprofloxacin
- Magnesium can bind these antibiotics, so the NIH says to take them at least 2 hours before or 4 to 6 hours after a magnesium supplement.2
- Diuretics
- Some diuretics raise how much magnesium the body loses in urine, and others lower it.1
- Prescription acid reflux and ulcer medicines
- Taken over a long time, these medicines can cause low blood levels of magnesium.1
If you take other supplements
- Zinc supplements in very high doses
- Very high doses of zinc can interfere with how the body absorbs and regulates magnesium.1
Side effects
- Magnesium in food and drinks is not harmful, because healthy kidneys remove any extra in urine.1
- The forms most often reported to cause diarrhea are magnesium carbonate, chloride, gluconate and oxide.2
- Extremely high intakes can lead to an irregular heartbeat and cardiac arrest.1
Ask a doctor first
- High intakes of magnesium from supplements and medicines can cause diarrhea, nausea and abdominal cramping.1
- Magnesium from supplements and medicines should not go above the upper limit unless a health care provider recommends it.1
- Bisphosphonates for osteoporosis and some antibiotics may not be absorbed well if taken too close to a magnesium supplement.1
These statements have not been evaluated by the FDA. A supplement is not a medicine.
The 4 products we reviewed that list magnesium
| Product | Form and serving | Magnesium per serving | Our score | Price a bottle | Buy |
|---|---|---|---|---|---|
 LeptiThinMax#1 in weight loss support | Capsules2 capsules | 1 mgunder 1% of daily need | 9.6 | $39 | Check price |
 Cellucare#4 in blood sugar support | Capsules1 capsule | 20 mg5% of daily need | 9.4 | $49 | Check price |
 SeroBurn#3 in weight loss support | Capsules2 capsules | 42 mg10% of daily need | 9.3 | $49 | Check price |
 GlucoTrust#6 in blood sugar support | Capsules1 capsule | 125 mg30% of daily need | 8.9 | $49 | Check price |
Questions people ask
What foods have magnesium?
Pumpkin seeds, chia seeds, almonds, spinach, cashews, peanuts, shredded wheat cereal and soymilk contain magnesium. Magnesium comes from many plant and animal foods and from drinks.
How much magnesium do I need per day?
For adults 19 and older, men need 400 to 420 mg of magnesium daily and women need 310 to 320 mg. These are the recommended dietary allowances, not suggested supplement doses.
What types of magnesium supplements are there?
Magnesium supplement forms include aspartate, citrate, lactate, chloride, oxide and sulfate. The NIH says aspartate, citrate, lactate and chloride tend to be absorbed better than oxide and sulfate.
How much magnesium is too much?
The adult upper limit for supplemental magnesium is 350 mg a day, unless a clinician recommends more. High intakes from supplements can cause diarrhea, nausea and abdominal cramping. Ask a clinician before starting a magnesium supplement.
Can magnesium cause diarrhea?
Yes, high intakes of magnesium from supplements can cause diarrhea. Magnesium carbonate, chloride, gluconate and oxide are the forms most often reported to cause it.
Which products we reviewed contain magnesium, and how much?
LeptiThinMax lists 1 mg of magnesium per serving, Cellucare lists 20 mg, SeroBurn lists 42 mg and GlucoTrust lists 125 mg. The listed serving is 2 capsules for LeptiThinMax and SeroBurn, and 1 capsule for Cellucare and GlucoTrust.
Also in these products
Sources
The products, amounts and prices come from each product's label and checkout, as its review shows them. AI drafts our pages from listed sources, figures are checked against them, and we have not tried the products.
- 1NIH Office of Dietary Supplements, Magnesium Fact Sheet for Consumersods.od.nih.gov/factsheetschecked
- 2NIH Office of Dietary Supplements, Magnesium Fact Sheet for Health Professionalsods.od.nih.gov/factsheetschecked