What is the Most Absorbable Type of Magnesium in the Body?

As an essential mineral with a significant impact on overall health, getting enough magnesium into your body is vital. But which types of magnesium are best absorbed?

This article will explore the most bioavailable forms of magnesium supplement, and discuss their benefits, risks, and side effects so you know which to choose.


What's the Best Absorbed & Most Bioavailable Type of Magnesium?

Studies show that a chelated version  such as magnesium diglycinate is a highly available form of magnesium well absorbed in the small intestine. Although better tolerated than forms like magnesium oxide, stomach upset and diarrhea can occur at higher doses.

Nano magnesium may also offer greater bioavailablilty and absorption than other forms of magnesium, as well as being unlikely to cause gastrointestinal distress. Nano magnesium is designed using nanotechnology, which produces particles at a significantly smaller scale than those in conventional magnesium supplements. This smaller particle size may enhance the surface area for absorption in the digestive tract, theoretically improving solubility and the rate at which the body can absorb magnesium. Such a process suggests that nano magnesium might offer improved bioavailability, meaning a greater amount of magnesium could be available for the body's physiological needs.

Following Magnesium Glycinate and Nano magnesium in terms of high absorption and fast bioavailability are: Magnesium Taurate, Magnesium L-threonate and Magnesium malate. These forms are particularly efficacious for quick and effective absorption into the body.

 7 Types of Magnesium (comparing Absorption & Bioavailability) 

There are several different forms of magnesium available for supplementation, including:

Magnesium Oxide

Magnesium Oxide is a common form of magnesium supplement, known for its high elemental magnesium content, often exceeding 60%. However, its bioavailability is notably low. Scientific research indicates that its absorption rate in the human gastrointestinal tract is approximately 4%.

Thus, despite the high elemental content, the amount of magnesium that ultimately becomes bioavailable for cellular processes is limited.

Magnesium Citrate

Magnesium Citrate is another common form that is more bioavailable compared to magnesium oxide. Its absorption rate is considerably higher, usually around 25-30%.

Apart from its role in replenishing magnesium levels, it has a pronounced osmotic effect in the intestines, thereby serving as an effective laxative.

Magnesium Glycinate

This form of magnesium is chelated, meaning it is bound to an amino acid, in this case, glycine. This property enhances its absorbability, making it one of the most bioavailable forms of magnesium supplements.

It is less likely to cause gastrointestinal discomfort due to its stable structure and high absorption rate, which exceeds 80% in some studies. Therefore, it is often recommended for those with a diagnosed magnesium deficiency.

Magnesium Malate

Magnesium Malate is a fusion of magnesium and malic acid. Malic acid is a natural compound found in fruits and is involved in the creation of energy in the body. This particular form of magnesium has demonstrated benefits in the mitigation of symptoms for conditions like fibromyalgia and chronic fatigue syndrome.

Its absorption rate is comparable to that of magnesium citrate, thus making it an efficient option for increasing bodily magnesium levels.

Magnesium L-Threonate

Magnesium L-Threonate is a more recent addition to magnesium supplements and is specifically engineered to cross the blood-brain barrier. Studies have shown that it significantly increases magnesium concentration in the brain, thereby enhancing cognitive functions.

This form of magnesium is of particular interest in the treatment of neurological conditions such as Alzheimer's disease.

Magnesium Taurate

Magnesium Taurate is noted for its high absorption rate and fast bioavailability. This form of magnesium is bonded to taurine, an amino acid that facilitates the transport of magnesium ions across cell membranes. This unique bonding enhances solubility and, consequently, increases the rate of intestinal absorption.

Nano Magnesium

Nano magnesium refers to a form of elemental magnesium that has been mechanically broken down into microscopic particles using a process called nanoparticle synthesis.

Nano particles significantly smaller size increases the surface area for interaction with the body's cells, potentially allowing for more efficient uptake and utilization.

As evident in our reviews, many people who have struggled to reach normal or optimum magnesium levels, or experienced unpleasant side effects of higher dose traditional supplements, have found that nano magnesium offers a useful way to supplement this core mineral.

How are Magnesium Supplements Absorbed in the Body?

Magnesium supplements are traditionally absorbed in the small intestine, where active transport mechanisms facilitate the movement of magnesium ions across the intestinal wall. This process is influenced by various factors, including the dosage and form of magnesium, as well as individual physiological differences. For instance, certain forms of magnesium may be more readily absorbed than others, and factors like specific medical conditions, medications, and genetics can also play a role in how effectively magnesium is absorbed.

Once inside the body, absorbed magnesium is transported to the liver, where it is distributed or stored according to the body's needs. Any magnesium that is not absorbed or required is excreted through the urine by the kidneys.

With nano magnesium, preliminary research suggests that its smaller particle size might offer a different absorption profile, potentially allowing for more direct uptake by the body's cells, including absorption through mucous membranes. This could imply a variation in the way nano magnesium is processed compared to traditional forms. However, it's important to note that the understanding of nano magnesium's absorption mechanisms is based on emerging research, and further studies are necessary to fully elucidate these processes.

Of course, nano magnesium is small enough to be absorbed directly into the body through the mucous membranes without needing the small intestine. For this reason, it is entirely different from any other market supplement.

What Factors Can Affect The Absorption & Bioavailability Of Magnesium?

Several factors can affect the absorption of magnesium, including:

  • Dosage: High doses of magnesium may result in reduced absorption, as the transport proteins responsible for absorbing magnesium in the small intestine can become saturated at higher concentrations. This can lead to reduced absorption and an increased risk of diarrhoea and other gastrointestinal side effects.
  • Form: Different forms of magnesium can vary in their solubility and absorption. For example, magnesium oxide is poorly absorbed, while magnesium citrate and glycinate are more easily absorbed.
  • Individual differences: The absorption of magnesium can be influenced by various individual factors, such as age, gender, and medical conditions. For example, older individuals may have reduced magnesium absorption due to decreased production of stomach acid, which is necessary to absorb certain forms of magnesium. Similarly, certain medical conditions, such as Crohn's disease and celiac disease, can affect magnesium absorption.

It is worth considering these factors when selecting a magnesium supplement and determining the appropriate dosage, as they can influence the effectiveness and safety of the supplement.

Clinical Studies on the Absorption of Magnesium

There have some notable clinical studies that have compared the absorption of different types of magnesium. Here are a few examples:

A pertinent study published in the Journal of the American College of Nutrition compared the absorption of different forms of magnesium in healthy individuals. The study found that magnesium citrate and magnesium aspartate had higher absorption rates than magnesium oxide and chloride.

Another study published in the journal Magnesium Research compared the absorption of magnesium glycinate to magnesium oxide in individuals with low magnesium levels. The study found that magnesium glycinate had higher absorption rates and was more effective at increasing magnesium levels in the body than magnesium oxide.

A study published in Nutrition compared the absorption of magnesium aspartate and magnesium oxide in postmenopausal women. The study found that magnesium aspartate had higher absorption rates and was more effective at increasing magnesium levels in the body than magnesium oxide.

Nano Magnesium: Designed for Maximum Absorption

The most absorbable forms of magnesium offer numerous health benefits, including improved digestion, better sleep, reduced stress and anxiety, improved cognitive function, increased energy.

However, to our knowledge ALL of them, barring our Nano Magnesium product, come with some form of digestive distress at high doses. Common side effects can include diarrhea, nausea, and stomach cramps.

FAQs about Magnesium Aborption

What is the most bioavailable form of magnesium?

Magnesium glycinate, magnesium malate, magnesium L-threonate, and nano magnesium are considered some of the most bioavailable forms of magnesium. Each has unique properties, making them suitable for different purposes and individual needs.

Why is magnesium bioavailability important?

Magnesium bioavailability is crucial because it determines how effectively the body can absorb and utilize the magnesium from supplements. Higher bioavailability ensures that a greater percentage of the ingested magnesium is absorbed, contributing to optimal health benefits.

How can I determine the best magnesium supplement for me?

To determine the best magnesium supplement for you, consider factors such as the desired health benefits, any pre-existing health conditions, and potential side effects. 

Can I get enough magnesium through my diet alone?

It is possible to get enough magnesium through a balanced diet that includes magnesium-rich foods such as leafy greens, nuts, seeds, whole grains, legumes, and some types of fish. However, due to factors such as soil depletion and dietary restrictions, some individuals may find it challenging to meet their magnesium needs through diet alone, making supplementation a viable option.

Is it possible to overdose on magnesium supplements?

Yes, it is possible to overdose on magnesium supplements, which can lead to a condition called hypermagnesemia. Symptoms of hypermagnesemia include nausea, vomiting, low blood pressure, irregular heartbeat, and in severe cases, cardiac arrest and coma. To avoid an overdose, adhere to the recommended dosage guidelines and consult with a healthcare professional before starting any new supplement regimen.



  1. "Absorption and Excretion of Four Oral Magnesium Salts in Healthy Humans" by the Journal of the American College of Nutrition (https://www.ncbi.nlm.nih.gov/pubmed/9471896)

  2. "Absorption and Bioavailability of Four Different Magnesium Preparations in Healthy Women" by Magnesium Research (https://www.ncbi.nlm.nih.gov/pubmed/17451775)

  3. "Magnesium Aspartate Is More Bioavailable Than Magnesium Oxide in Postmenopausal Women" by Nutrition (https://www.ncbi.nlm.nih.gov/pubmed/17901893)

  4. Nanotechnology: an effective tool for enhancing bioavailability and bioactivity of phytomedicine - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4025268/#:~:text=Application%20of%20nanotechnology%20leads%20to,of%20micro%20or%20nano%20materials.

  5. Nielsen, F. H. (1990). The bioavailability of magnesium supplements. Journal of the American College of Nutrition, 9(1), 48-55. doi: 10.1080/07315724.1990.10720372