Magnesium Threonate: What Is It, How Does It Compare, and What Should You Know?

How it works

Magnesium is an essential mineral involved in over 300 enzymatic reactions in the human body. It is crucial for the synthesis of proteins, DNA and RNA, and for the regulation of muscle and nerve function, blood glucose control, and blood pressure. Magnesium is also necessary for the structural development of bone and is required for the synthesis of the antioxidant glutathione.

Magnesium threonate is a form of magnesium where the mineral is chelated (bound) to L-threonic acid, a metabolite of vitamin C. Chelation can influence both the absorption and the distribution of magnesium in the body. The rationale for binding magnesium to L-threonic acid is that this combination may affect how magnesium crosses cell membranes, including those in the nervous system. However, all forms of magnesium must be broken down in the digestive tract before the mineral can be absorbed. The type of compound (such as threonate, citrate, or oxide) affects how much magnesium is delivered to the body and how well it is tolerated.

After ingestion, magnesium is absorbed primarily in the small intestine, with efficiency depending on the amount consumed and the specific magnesium salt. The body regulates magnesium levels tightly, and excess is excreted by the kidneys.

Magnesium contributes to the normal functioning of the nervous system, provided the product is at least a source of magnesium.

Magnesium threonate is sometimes described as having unique properties related to its absorption and potential to cross the blood-brain barrier. However, no health claims regarding cognitive effects or brain-specific benefits are authorised for any magnesium form.

Magnesium is found throughout the body, with approximately 50–60% present in the bones and most of the remainder in soft tissues. The adult body contains about 25 grams of magnesium.

What the research and authorised claims say

Only certain health claims for magnesium are authorised in the European Union. These claims can be used only if the product is at least a source of magnesium. The authorised claims are:

• Magnesium contributes to the maintenance of normal bones.
• Magnesium contributes to normal energy-yielding metabolism.
• Magnesium contributes to a reduction of tiredness and fatigue.
• Magnesium contributes to normal muscle function.
• Magnesium contributes to the normal functioning of the nervous system.

These claims apply to all forms of magnesium, including threonate, as long as the product meets the minimum magnesium content required to be called a 'source'.

Magnesium is present in a wide variety of foods, including leafy green vegetables, nuts, seeds, whole grains, and legumes. However, surveys indicate that some populations may not meet recommended intakes from diet alone. Supplements can help increase magnesium intake, but only the above claims are permitted for any supplement that qualifies as a source of magnesium.

Magnesium contributes to a reduction of tiredness and fatigue, provided the product is at least a source of magnesium.

While some studies have investigated the bioavailability of different magnesium forms, including threonate, citrate, oxide, and others, the clinical significance of differences in absorption remains under investigation.

It is important to note that claims about effects beyond the authorised list (such as mood, sleep, or cognitive performance) are not permitted for any magnesium supplement, regardless of form.

Key limitations

• Claims about effects beyond the authorised list (such as mood, sleep, or cognitive performance) are not permitted.
• Bioavailability and absorption rates can vary between forms, but individual responses may differ and are not always predictable.
• Some forms of magnesium (such as oxide) may be less well absorbed than others (such as citrate or threonate), but the clinical significance of these differences is still under investigation.

How to choose

When selecting a magnesium supplement, consider the following factors:

• Form: Different forms have different absorption rates and tolerability. Magnesium citrate and oxide are the most common in Tigoo's range. Magnesium threonate is less common but available.
• Elemental magnesium content: The amount of actual magnesium per serving can vary by form and brand. Check the label for the 'elemental magnesium' amount.
• Dosage: The median dose in Tigoo's range is 120 mg per serving. This is below the tolerable upper intake level for adults, which is 250 mg per day from supplements (not including food sources).
• Other ingredients: Some products include additional vitamins or minerals. Check for allergens or additives if you have sensitivities.
• Intended use: Only the authorised claims listed above can be considered when choosing a product for specific health goals.

It is also important to consider the form of the supplement (tablet, capsule, powder, or liquid), as this can affect convenience and personal preference. Some people may prefer powders or liquids if they have difficulty swallowing pills, while others may find capsules more convenient for travel or daily use.

Price and brand reputation may also influence your choice. Look for products from reputable manufacturers that provide clear labelling of magnesium content and form. Some brands may offer third-party testing or certifications for quality assurance.

When comparing products, look for the form, dose, and whether the product meets the minimum magnesium content to qualify for authorised claims.

Comparison of Common Magnesium Forms in Tigoo's Range

Form	Number of Products	Median Dose (mg)	Notes
Magnesium citrate	39	120	Common, well-absorbed
Magnesium oxide	30	120	High elemental content, lower absorption
Magnesium threonate	Data not specified	Varies	Less common, chelated form
Other forms (malate, bisglycinate, etc. )	Varies	Varies	May offer different tolerability

Absorption and tolerability

The absorption of magnesium from supplements depends on both the form and the presence of other dietary components. Organic magnesium salts (such as citrate, lactate, and threonate) tend to be better absorbed than inorganic salts (such as oxide and sulfate). However, the absolute difference in absorption may not always translate into significant differences in clinical outcomes for most healthy individuals.

Some forms, such as magnesium oxide, contain a higher percentage of elemental magnesium by weight but are less well absorbed, which can lead to gastrointestinal side effects like diarrhoea at higher doses. Magnesium citrate and threonate are often considered more gentle on the digestive system, but individual tolerance can vary.

Magnesium threonate is sometimes marketed as being less likely to cause laxative effects compared to other forms, but this is not an authorised claim and evidence is limited.

Product labelling and regulations

In the EU and many other regions, supplement labels must specify the amount of elemental magnesium per serving and the form of magnesium used. Products must also meet minimum content requirements to qualify as a 'source' of magnesium and to use authorised health claims.

Some products may combine multiple forms of magnesium or include additional nutrients such as vitamin B6, which is involved in magnesium metabolism. However, only claims authorised for magnesium itself can be made unless the product also meets requirements for other nutrients.

Safety, interactions and risk groups

Magnesium supplements are generally well tolerated at recommended doses. However, excessive intake can cause gastrointestinal symptoms such as diarrhoea, nausea, and abdominal cramping. These effects are more likely with magnesium salts that are less well absorbed, such as magnesium oxide.

The tolerable upper intake level (UL) for supplemental magnesium for adults is 250 mg per day, not including magnesium obtained from food sources. Exceeding this amount increases the risk of adverse effects, especially in sensitive individuals.

People with kidney problems are at particular risk, as impaired kidney function can reduce the body's ability to excrete excess magnesium, potentially leading to elevated blood magnesium levels (hypermagnesemia). Symptoms of hypermagnesemia may include low blood pressure, confusion, slowed heart rate, and in severe cases, cardiac arrest.

Other groups who should consult a healthcare professional before using magnesium supplements include:

• People taking certain medications (such as diuretics, antibiotics, or medications for heart disease) that may interact with magnesium.
• Pregnant or breastfeeding women, due to limited safety data for high-dose supplementation.
• Children, as safety and appropriate dosing may differ from adults.

If you are taking prescription medication or have a medical condition, always seek advice from a healthcare provider before starting any supplement.

Magnesium can also interact with certain medications by affecting their absorption or activity. For example, magnesium can reduce the absorption of some antibiotics (such as tetracyclines and quinolones) if taken at the same time. To avoid interactions, it is often recommended to separate magnesium supplements from these medications by at least two hours.

Supplements should not be used as a substitute for a varied and balanced diet.

Dietary sources and role in nutrition

Magnesium is naturally present in many foods. Good dietary sources include:

• Leafy green vegetables (such as spinach and kale)
• Nuts and seeds (such as almonds, cashews, pumpkin seeds)
• Whole grains (such as brown rice, oats, and whole wheat bread)
• Legumes (such as black beans and lentils)
• Some fish (such as mackerel and salmon)
• Avocado, bananas, and dark chocolate

The recommended dietary allowance (RDA) for magnesium varies by age, sex, and life stage. For most adults, the RDA is between 300 and 400 mg per day from all sources. Most people can meet their magnesium needs through a balanced diet, but supplements may be useful for those who have increased requirements or difficulty obtaining enough from food.

How magnesium threonate compares to other forms

Magnesium threonate is one of several forms of magnesium available as a dietary supplement. Other common forms include magnesium citrate, oxide, malate, bisglycinate, and chloride. Each form has unique properties that can influence absorption, tolerability, and suitability for different individuals.

Magnesium citrate is widely used due to its relatively high absorption and gentle effect on the digestive system. Magnesium oxide, while containing a high percentage of elemental magnesium, is less well absorbed and more likely to cause gastrointestinal side effects. Magnesium bisglycinate and malate are also popular for their good absorption and tolerability.

Magnesium threonate is less common and typically more expensive than other forms. It is marketed for its chelated structure and potential to cross cell membranes efficiently, but no unique health claims are authorised for this form. All forms, when providing sufficient magnesium, are eligible for the same authorised claims relating to muscle function, energy metabolism, bone maintenance, and nervous system support.

When choosing a form, consider individual tolerance, cost, and the specific magnesium content per serving. There is no evidence that one form is universally superior for all users; personal preference and response may play a significant role.

Practical tips for supplement use

• Take magnesium supplements with food to improve absorption and reduce the risk of gastrointestinal discomfort.
• Start with a lower dose and increase gradually if needed, to assess tolerance.
• Check the label for the form and amount of elemental magnesium.
• Store supplements in a cool, dry place, away from direct sunlight.
• Keep supplements out of reach of children.

If you experience persistent side effects such as diarrhoea, nausea, or abdominal pain, discontinue use and consult a healthcare professional.