Are You Being Misled About Magnesium?

published by Anna O'Byrne on in

Are You Being Misled About Magnesium?

Supplement companies are meant to be better than pharmaceutical companies. More ethical, more honest, more altruistic.

But sometimes even warm and fuzzy health brands get caught up in ruthless marketing.

Unfortunately, this is true in the magnesium industry.

To sell more product, some magnesium brands are making claims that aren’t founded in science.

If you’ve heard that magnesium glycinate is the most absorbable form, you’ve already been exposed.

A More Absorbable Magnesium?

There’s a reason the marketing battle starts with absorbability.

Absorption matters because only an absorbable magnesium is ‘bioavailable’ (in other words, available to cells throughout your body). If a supplement is absorbable, it’s more likely to work.

Many brands claim higher absorption.

For example, one leading magnesium glycinate brand says:

“Magnesium bisglycinate appears to be the safest and most effective form of magnesium for human absorption”

Another magnesium bisglycinate brand says:

“…You would have to take 4 times the amount of magnesium citrate to get the equivalent amount of magnesium bisglycinate.”

Natural Calm is magnesium citrate, so naturally, we wanted to understand the research behind these claims.

Here, I’ll share what the science really says.

How Magnesium is Absorbed: Creative Marketing vs. Objective Science

Let’s start with what we really know about how magnesium is absorbed.

After you toss back your magnesium drink, tablet, or capsule, that magnesium is dissolved in the gastric fluid of the stomach.

The dissolved magnesium becomes ‘ionic’ – the form that can be absorbed in the small intestine.

The magnesium ions then enter the bloodstream for transport to tissues and organs across the body.

Now, this is where many marketers are getting very creative. You’ll hear a wide range of science-sounding ideas about what happens to the magnesium molecule in the intestine.

Some companies claim that only magnesium glycinate can effectively pass through the intestine to the bloodstream.

This is smart marketing, but is it science?

It’s not.

Natural Calm Canada commissioned research by a scientific advisor and PhD in microbiology, Dr. Jon-Paul Powers – formerly of the National Health Products Directorate, Health Canada.

When Dr. Powers scoured the peer-reviewed science for the source of these claims, no studies were found. None.

What the Science Does Say About Absorption

We can all speculate about what makes one form of magnesium more absorbable. We can claim that amino acids help, or that tiny unicorns chauffeur the magnesium into the bloodstream.

Scientists believe that ‘solubility’ is what matters. Magnesium supplements that dissolve well are more effectively taken up in the intestine.

We know that stomach acid helps with solubility; it keeps the magnesium broken down.

But as the magnesium ions progress through the small intestine, that acidity drops…which means some forms of magnesium may revert to a less soluble form.

Magnesium citrate, however, has staying power. It’s proven to remain soluble even as acidity drops. Those useful magnesium ions? They make themselves available for uptake throughout the intestine.

Researchers believe this solubility advantage is one reason magnesium citrate directly increases magnesium blood plasma levels.

Yes, we’ve backed that up with data.

Magnesium Citrate vs. Magnesium Glycinate

Here, we get into trickier terrain. Comparing absorption is not as easy as you might imagine.

Which is perhaps why there are no published, peer-reviewed studies comparing magnesium citrate to magnesium glycinate – two of the most popular forms.

So, why are magnesium glycinate brands directly comparing their products to magnesium citrate?

Good question. They have no scientific ground on which to stand.

Some magnesium glycinate brands make sweeping statements without referencing studies. Others cite dubious studies that are either unpublished or not peer-reviewed.

We prefer reputable science.

Here’s what the credible research does say about citrate vs. glycinate:

  • When magnesium bisglycinate was compared with magnesium oxide, researchers found little difference in absorbability and bioavailability. But when another study compared magnesium citrate to magnesium oxide, magnesium citrate was found more absorbable and more bioavailable. (Read that twice.)
  • A detailed review ranked magnesium citrate and magnesium glycinate in the same category, as equally absorbable forms of magnesium.
  • One well-designed study showed that compared to a magnesium chelate (magnesium glycinate is a type of chelate), only magnesium citrate supplementation increased blood plasma and salivary levels of magnesium.

The conclusion?

The only peer-reviewed, published research we have suggests this: magnesium citrate is on par with or more absorbable than magnesium glycinate.

Facts vs. Myths About Magnesium Absorption

So, what have we learned here? It comes down to a handful of facts, in contrast to what we’ll generously dub “myths”.

Fact: Magnesium supplements that are more soluble are more absorbable. That’s why magnesium taken as a liquid may be more effective than tablets or capsules.

Myth: Magnesium citrate is flushed out of the body and not absorbed.

Fact: Studies show that magnesium citrate is very absorbable and directly increases blood plasma and salivary levels of magnesium.

Myth: Magnesium needs an amino acid to be absorbed, so magnesium glycinate is better.

Fact: If anything, the research suggests that magnesium glycinate is less absorbable than magnesium citrate.

Don’t Keep Calm About Fake Science

Let me wrap up with an illuminating story.

A natural health practitioner we know once wrote to one of the most vocal of the Canadian magnesium glycinate brands asking for the source of their claims. From their marketing, you would think they were swimming in robust science.

But, no.

The company’s ND on staff wrote back saying, “There currently is no research that directly compares magnesium bisglycinate and magnesium citrate per se.”

So, there you have it, “no research.”

It is forgivable to make mistakes in interpreting the science. But when supplement companies deliberately misrepresent facts, it tarnishes the entire industry.

If you want to stand up for truth in health marketing, share this post!

(Update September 22, 2017: Want more data? Now you can review the results from a NEW double-blind study comparing Natural Calm magnesium with CanPrev and Lorna Vanderhaeghe magnesium glycinate brands.)



[2] Coudray et al. (2005). Magnesium Res  18(4): 215-23

[3] Ranade and Somberg (2001). Am J Therapeutics 8: 345-357

[4] Siebrecht, S. (2013). Journal International de la medicine orthomoleculaire et analgogue 144

[5] Lindberg et al. (1990).  J Amer Col of Nutrition, 9(1): 48-55

[6] Firoz and Graber (2001). Magnesium Research 14(4): 257-262

[7] Coudray et al. (2005) Magnesium Research 18(4): 215-23

[8] Wilimzig et al. (1996). Euro J Clin Pharmacol 49: 317-323

[9] Ranade and Somberg (2001). Am J Ther 8: 345-357

[10] Couday et al. (2005) Magnesium Res 18(4):215-23

[11] Lindberg et al. (1990) J Amer Col Nutr 9(1): 48-55

[12] Schuette et al. (1994) J Parenter Enteral Nutr 18: 430-435

[13] Ranade and Somberg (2001). Am J Ther 8: 345-357

[14] Walker et al. (2003) Magnes Res 6(3): 183-91

[15] Ho, Cecilia, ND. Personal electronic correspondence. Dated August 3, 2016.


Anna O'Byrne

Anna O'Byrne writes, manages social media and runs digital marketing for Natural Calm Canada. If you have questions or are interested in collaborating, email Anna at