Magnesium forms compared

For general information about magnesium, its functions and safe use, visit our main Magnesium page.

What determines the differences between magnesium forms?

Magnesium cannot be consumed in an unbound form. It must always be bound to another molecule. This molecule determines two things: how much elemental magnesium the compound contains per gram and how the body absorbs it.

Elemental magnesium is the amount of pure magnesium contained in each gram of the compound. This amount is stated on the label and is the only figure that matters when comparing products.

The most relevant distinction is between organically bound forms, such as citrate, malate, bisglycinate and taurate, and inorganically bound forms, such as oxide, sulfate and carbonate.

Organically bound forms are generally more soluble and follow a different absorption pathway in the intestines.

The most common forms

Magnesium oxide

Magnesium oxide is the cheapest and most widely produced form of magnesium. It contains a high percentage of elemental magnesium by weight, up to approximately 60%. This means that a relatively high amount can be stated on the label while keeping the capsule small.

However, magnesium oxide has limited solubility in water, which affects its absorption pathway in the intestines. It is widely used in inexpensive supplements and multivitamins.

For people who make a conscious choice based on composition, magnesium oxide is the least interesting option within the spectrum of magnesium forms.

Did you know that magnesium oxide contains so much elemental magnesium per gram that it was previously used as a laxative? This says something about how it works in the intestines.

Magnesium citrate

Magnesium citrate is an organically bound form in which magnesium is attached to citric acid. It dissolves well in water and is therefore processed effectively in the gastrointestinal tract.

It is one of the most commonly used forms in high-quality supplements and has a broad range of applications. Magnesium citrate contains approximately 16% elemental magnesium by weight.

Magnesium malate

Magnesium malate is magnesium bound to malic acid, also known as malate. Malate occurs naturally in the citric acid cycle, the biochemical process through which cells produce energy.

Magnesium malate contains approximately 15% elemental magnesium and is generally well tolerated by the stomach. It is often used during the day.

Magnesium bisglycinate

Magnesium bisglycinate is a chelated form in which magnesium is bound to two glycine molecules.

Chelation means that the magnesium is securely enclosed within the amino acid molecule. This allows the compound to be absorbed through the amino acid transport pathway in the intestines. This pathway differs from that used by inorganic or simple organic magnesium compounds.

Glycine plays a role in the nervous system as an inhibitory neurotransmitter. This combination makes magnesium bisglycinate a popular choice for evening use.

It contains approximately 14% elemental magnesium and is the gentlest magnesium form for the stomach.

Magnesium taurate

Magnesium taurate is magnesium bound to taurine, an amino acid that occurs naturally in the body and plays a role in the nervous system and heart function.

It contains approximately 8% elemental magnesium by weight. Magnesium taurate is often used in formulations focused on mental balance and is frequently combined with magnesium bisglycinate.

Magnesium L-threonate

Magnesium L-threonate is a relatively new form in which magnesium is bound to L-threonate, a substance produced when vitamin C is broken down.

This form has been specifically studied for its ability to cross the blood-brain barrier. It contains approximately 8% elemental magnesium by weight and is the most expensive form in this overview.

For general daily use, magnesium citrate or magnesium bisglycinate are usually more cost-effective.

Magnesium lysinate

Magnesium lysinate is magnesium bound to lysine, an essential amino acid that plays a role in protein metabolism and is involved in transporting magnesium into cells.

It is less common in the Dutch supplement market than magnesium citrate or magnesium bisglycinate. It is sometimes included in combination formulas.

Magnesium pidolate

Magnesium pidolate is magnesium bound to pidolic acid, a metabolite involved in the glutamate cycle.

It is available as a food supplement in the EU. Magnesium pidolate is more commonly used in other European countries than in the Netherlands.

It is considered a successor to magnesium orotate, which is no longer permitted as a food supplement in the EU. More information is provided below.

Magnesium aspartate

Magnesium aspartate is magnesium bound to aspartic acid, an amino acid that plays a role in the citric acid cycle.

It is one of the older organically bound magnesium forms and is sometimes used alongside other forms in combination products.

Magnesium glycerophosphate

Magnesium glycerophosphate is magnesium bound to glycerophosphate, a substance involved in energy metabolism.

It is used in combination formulas focused on energy and recovery.

Special magnesium forms

Magnesium orotate

No longer permitted in the EU.

Magnesium orotate is magnesium bound to orotic acid. It is not included on the list of permitted mineral forms under the EU Food Supplements Directive and is therefore not allowed as a food supplement in the EU.

If you are specifically looking for magnesium orotate, consider magnesium pidolate as an alternative.

Magnesium sulfate — Epsom salt

Magnesium sulfate is widely known as Epsom salt and is also used in bath bombs. Magnesium is absorbed through the skin only to a limited extent.

When taken orally, magnesium sulfate has a strong laxative effect at higher doses. It is therefore not a common choice for daily magnesium supplementation.

Magnesium hydroxide — medicinal product

Magnesium hydroxide is registered as a medicinal product in the Netherlands and is therefore not considered a food supplement.

It is used as an antacid and laxative.

Magnesium phosphoricum — cell salt no. 7

Magnesium phosphoricum is cell salt number 7 within the Schüssler system. It is offered as a highly diluted homeopathic preparation and therefore falls outside the scope of conventional food supplements.

Magnesium phosphoricum can be identified on the label by terms such as “Magnesium phosphoricum D6” or another dilution designation.

More information about cell salts will be provided in a separate article in our Knowledge Base.

Combination products: several forms in one capsule

An increasing number of supplements combine two or more magnesium forms in a single product. Examples include citrate with bisglycinate or malate with taurate.

Different magnesium forms are absorbed through different pathways. Combining them may therefore distribute absorption across the various transport mechanisms available in the intestines.

Combination products also offer more flexibility for use at different times of the day: the malate component during the day and the bisglycinate component in the evening.

You can recognize a combination product by the inclusion of several magnesium compounds in the ingredient list.

A combination of magnesium bisglycinate and magnesium citrate is more logical than a combination of magnesium bisglycinate and magnesium oxide. Check whether the cheaper component is dominant in the blend.

Find out more in the article “Combining supplements: what works together and what doesn’t?”

Magnesium and vitamin B6

Vitamin B6, preferably in its active form pyridoxal 5′-phosphate or P-5-P, plays a role in transporting magnesium into cells.

Both substances are involved in similar processes within the nervous system and are frequently combined in supplements.

On the label, vitamin B6 may be listed as pyridoxine hydrochloride, the basic form, or pyridoxal 5′-phosphate, the active form, alongside the magnesium compound.

Magnesium and calcium

Magnesium and calcium partially compete for the same absorption pathways in the intestines. For optimal absorption of both minerals, they should preferably be taken at different times.

A magnesium deficiency can also interfere with calcium regulation in the body. In other words, the two minerals affect each other’s balance.

Athletes and increased requirements

Athletes and people with an active lifestyle lose additional magnesium through perspiration. During intensive training, magnesium requirements may therefore be higher than can be met through food alone.

The choice of magnesium form is particularly relevant for athletes. Magnesium citrate or magnesium malate may be used during the day around training, while magnesium bisglycinate may be used in the evening to support recovery.

Find out which foods naturally contain high amounts of magnesium in the article “Magnesium in food”

Safety

When should you take extra care? If you take medication, are pregnant, are breastfeeding or have a medical condition, consult your doctor or pharmacist before use.

Safe upper intake level: The EFSA has established a safe upper intake level of 250 mg of elemental magnesium per day from supplements for adults. Higher doses may cause diarrhea and gastrointestinal discomfort.

Medication use: When using antibiotics, thyroid medication or beta blockers, take magnesium at least two hours apart from these medicines. Find out more on the page “Supplements and medication — What you need to know”

Frequently asked questions

Which form of magnesium is absorbed best?

There is no single answer to this question. Absorption depends on the magnesium form, the time of administration and individual stomach sensitivity.

Organically bound forms such as magnesium citrate, magnesium malate and magnesium bisglycinate follow a different absorption pathway from inorganically bound magnesium oxide.

Because it is chelated, magnesium bisglycinate uses a specific amino acid transport pathway. The best form therefore depends on when you take it and what you use it for.

What is elemental magnesium and why is it stated on the label?

Elemental magnesium is the amount of pure magnesium contained in a compound. This is separate from the weight of the molecule to which the magnesium is bound.

Two products stating “300 mg magnesium” on the label contain the same amount of elemental magnesium, regardless of the form used.

When should I choose magnesium malate and when should I choose magnesium bisglycinate?

Magnesium malate is more commonly chosen for daytime use because malate plays a role in energy metabolism.

Magnesium bisglycinate is more commonly chosen for evening use because of glycine’s role in the nervous system.

Both forms can be taken at any time of day.

Can I combine magnesium with vitamin B6?

Yes. Vitamin B6 and magnesium are frequently used together.

Vitamin B6 in its active P-5-P form is the most direct form. When choosing a combination product, check whether vitamin B6 has been added as pyridoxine hydrochloride or pyridoxal 5′-phosphate.

Why do magnesium supplements vary so much in price?

The raw material costs of magnesium bisglycinate and magnesium malate are higher than those of magnesium oxide. Chelated forms also require an additional production step.

Certifications, excipients and capsule quality also affect the price.

Is magnesium ascorbate also a form of magnesium?

Yes. Magnesium ascorbate is magnesium bound to ascorbic acid, or vitamin C. It therefore provides both magnesium and vitamin C.

However, the amount of elemental magnesium per gram of the compound is relatively low. It is not a replacement for a conventional magnesium supplement if you specifically want to supplement magnesium.

What is magnesium orotate and why is it no longer available?

Magnesium orotate was a popular magnesium form in which magnesium is bound to orotic acid.

It is no longer permitted as a food supplement in the EU. Magnesium pidolate is considered an available alternative.

Can I take magnesium and calcium together?

Preferably not. Magnesium and calcium partially compete for the same absorption pathways in the intestines.

For optimal absorption, take them at different times.

Does magnesium affect other nutrients?

Yes. Magnesium acts as a cofactor in the activation of vitamin D in the liver and kidneys. Without sufficient magnesium, the body may convert vitamin D into its active form less efficiently.

Magnesium also affects calcium balance and works together with vitamin B6 in supporting the normal functioning of the nervous system.

Should magnesium sulfate be included in my daily intake?

That depends on how it is used.

Magnesium sulfate applied to the skin, such as in an Epsom salt bath or foot bath, is absorbed only to a limited extent and contributes very little to daily magnesium intake.

When taken orally, magnesium sulfate does provide elemental magnesium. However, it can have a strong laxative effect at higher doses and is not a common choice for daily supplementation.

If magnesium sulfate is listed on a supplement label, check the amount of elemental magnesium per daily dose. This amount should be included in your total intake.

Would you like personal advice?

The Magnesium choice guide helps you compare products based on their elemental magnesium content, excipients and price.

Still unsure which product to choose? Our qualified druggists and orthomolecular therapists will be happy to help:

• by telephone on +31 318 – 64 89 89;
• via WhatsApp on +31 6 83 70 20 40;
• by email at info@gezondheidaanhuis.nl.