Our Members Asked:
Which is the best form of magnesium to take - one that contains the most magnesium and is best absorbed?

Answer:
While different magnesium compounds vary in the amount of magnesium they contain (for example, just 16.2% of magnesium citrate is actual magnesium -- the rest is citric acid, while 14.1% of magnesium glycinate is magnesium, and 8% of magnesium threonate is magnesium), manufacturers are required to list the amount of actual, or "elemental" magnesium on labels so you can compare the actual amount of magnesium provided by supplements, even if they contain different forms. However, be aware that ConsumerLab.com has found some magnesium supplements in the past which were not labeled properly.
Absorption and even certain side-effects can vary by form, as can cost. You can read more about this in the "What to Consider When Buying" section of the Magnesium Supplements Review. In addition, we identify products which contain a form of magnesium with good absorption, and which specific product was the most economical way to get this type of magnesium.
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Tracy2907
December 21, 2023I got very bad diarrhea as soon as I started taking 250mg of magnesium citrate.At first, I thought it was a result of my IBS. But then I discovered that my daily multi-vitamin has 150mg of magnesium, which means I was actually taking 400mg a day, more than my body could tolerate, so I stopped the magnesium supplement altogether.
I advise everyone taking multivitamins to pay attention to how much they're getting of a particular supplement in the multivitamin when making a decision about other supplements to add to their daily regime.
Thank you for sharing this. You can find information about which forms of magnesium are more or less likely to have a laxative effect in the ConsumerTips section of our Magnesium Supplements Review https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#forms.
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Kandy
August 24, 2023I found that I don’t get loose stools when I take magnesium glycinate from KAL. It says it’s fully chelated. I’m trying to find out any reviews for the company. I do not have financial interest in this product
Thank you
As noted in the ConsumerTips section of our Magnesium Supplements Review, magnesium glycinate, particularly chelated magnesium glycinate, has less of a laxitive effect than some other forms of magnesium. For more about this, see https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#absorption.
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John2897
April 16, 2022I am trying to understand a proper Magnesium dose. For example, if only 16.2% of Magnesium Citrate is elemental Magnesium, and only 30% of Magnesium Citrate is absorbed, does this mean that 100mg of Magnesium Citrate provides only 4.8mg of Magnesium?
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Lucille2894
March 01, 2022What is magnesium threonate and what is it used for?
Magnesium threonate is a form of magnesium found in products such as Magtein (see our CL Answer about this product https://www.consumerlab.com/answers/do-magnesium-supplements-like-magtein-help-memory-or-protect-against-alzheimers-disease/magnesium-memory/), which are often promoted to improve memory and cognition. For more details, see the clinical evidence for magnesium threonate in the "What It Does" section of our Magnesium Supplements Review https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#threonate. Also see "Choosing the right form of magnesium" in the Review to see out it compares to other forms of magnesium https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#forms.
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K M
August 10, 2021How does absorption of magnesium glycinate compare with magnesium bisglycinate?
(Glycinate was not listed in the comparison table in the review.)
The terms "magnesium glycinate" and "magnesium bisglycinate" refer to the same form of magnesium. We've updated the table in our review to clarify: https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#forms-table
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alaa2885
June 16, 2017greetings
thanks for the great work
the one thing I've always wanted to get right is the actual amount of Magnesium
( elemental ) in a product, how to know that ?
thanks
Thanks for your kind words. On a properly labeled supplement, the amount of elemental magnesium should be the amount shown. The label should also indicate the form of magnesium used. More details are in the Magnesium Review, including an example of an incorrectly labeled product. See https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#buying.
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LINDA2873
June 07, 2016just received a notice of a class action lawsuit involving chelated magnesium. Do not understand the issue. less than was listed..do you know
Hi Linda - We've just posted more information about this here: https://www.consumerlab.com/recalls/12962/vitacost-settles-magnesium-supplement-lawsuit/
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Doug2869
December 31, 2015What about topical Magnesium sprays?
Hi Doug - You can find information about magnesium cream and sprays in the Magnesium Supplements Review, here: https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#spray
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Don2867
December 31, 2015I have found that magnesium Malate does not cause diarrhea no matter how much one takes. Remember not to take magnesium and calcium at the same time. For the reasons see Dr. Nan Kathryn Fuchs articles on Osteoporosis. I take my calcium in the AM and my magnesium in the PM. I alternate magnesium malate from source naturals with a complex of magnesium Magtein, taurate and glycinate called MagTech from Natural Stacks.
Hi Don - Thank you for sharing your experience with magnesium malate; there are two other forms of magnesium that are less likely to cause diarrhea, which are discussed in the Magnesium Supplements Review: https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#buying. Please be aware, however, that there are other concerns with taking too much magnesium: https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#cautions
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bdmesq@gmail.com
December 30, 2015you wrote:
for example, just 16.2% of magnesium citrate is actual magnesium -- the rest is citric acid
If it states: each capsule contains :
magnesium [as magnesium citrate] 70 mg
does this then means 70 mg elemental magnesium??[if i understood you well] ?
thanks
Hi Harold - Yes, on a properly labeled magnesium supplement that states "magnesium (as magnesium citrate) 70 mg", this should mean it contains 70 mg of elemental magnesium -- although the only way to know for sure is to confirm this through testing.
The "What to Consider When Buying" section of the Magnesium Supplements Review provides more information about reading labels, as well as an example of an improperly labeled magnesium supplement: https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#tips
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Anisa2857
January 08, 2015Iv'e found that loose powder Magnesium Citrate in half teaspoon to one teaspoon measure in 8 ounces of water is a very good digestive for the next morning. Take before bed and you will feel great to start your day when you get up.
JOHN2858
July 10, 2016started taking calcium gluconate-magnesium citrate powder (1 tsp.=100 mg) from Natural Vitality (CalMag) and been sleeping like a log since.
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Hi Michael and Kim - You can read more about Magnesium-L-threonate and Magtein here: https://www.consumerlab.com/answers/%20/magnesium_memory/
Michael2854
January 08, 2015Do you have any research on Dimagnesium Malate marketed under the Jigsaw Health brand?
We have not tested this product, but do have some information about magnesium malate in the Magnesium Review: https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#buying
Also, we are not aware of any studies using this combination of ingredients.
Hi Michael - Just letting you know that we have since tested this product, as part of our Magnesium Supplements Review published on June 6, 2015. You can see the results here: https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#results
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Al2843
January 07, 2015You can't beat ReMag, a liquid form. It's absorbed at the cellular level and doesn't cause diarrhea. All the pill kinds caused that problem for my wife, but since I got her on ReMag, the problem ceased. I also take it. It seems pricey compared to something like Mag Glycinate which runs about 3 cents per capsule, but you don't need as much of it to get a good dose. A bottle lasts us about 3 months. Google it and then find the link to the doctor who developed it and you can learn more. She has written several widely-available books on magnesium and the body's need for it. My poorer second choices would be magnesium glycinate or magnesium taurate, but only if you are on a tight budget. In the long run they're not as effective and you will be spending more on t-paper.
Hi Al - We have added information about ReMag to the Magnesium Supplements Review. You can read about it at https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#remag
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KIM2835
January 07, 2015What is Magnesium L-Threonate? Your test report did not mentioned it.
Michael2837
July 22, 2015Where is Magnesium Bicarbonate mentioned?
Hi Michael - Magnesium bicarbonate is discussed in the "Choosing the right form of magnesium" section of the Magnesium Review, here: https://www.consumerlab.com/reviews/magnesium-supplement-review/magnesium/#forms
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