All magnesium supplements come in the form of a compound, where magnesium is bound to another substance. This combination affects how well the magnesium is absorbed and tolerated by the body, as well as any additional or synergistic properties the supplement may offer.
Because of this, not all magnesium supplements are absorbed or utilised by the body in the same way.
Some forms are highly bioavailable, meaning they are absorbed efficiently and well tolerated, while others are poorly absorbed and more likely to cause digestive side effects. In many cases, the “best” form of magnesium depends on what you are looking to support — whether that’s sleep, muscle recovery, energy production, cognitive function, or general wellbeing.
Below, we’ll break down five of the most popular and effective forms of magnesium, along with their key differences, so you can choose the best magnesium supplement for your needs.
1. Magnesium Glycinate
Best for: Sleep, relaxation, muscle function, and general magnesium supplementation.
Magnesium glycinate (also known as magnesium bisglycinate) is widely considered one of the best forms of magnesium due to its excellent absorption and gentle effect on digestion.
It is created by binding magnesium to glycine, an amino acid involved in relaxation and nervous system function. This chelated structure helps improve magnesium absorption while reducing the likelihood of digestive discomfort commonly associated with lower-quality forms such as magnesium oxide.
Because of this, magnesium glycinate has become one of the most popular forms of magnesium for individuals looking to support sleep, relaxation, muscle recovery, and overall wellbeing.
What makes magnesium glycinate particularly unique is the amino acid it is bound to. Glycine acts as an inhibitory neurotransmitter within the central nervous system4 and has been studied for its potential role in supporting relaxation and sleep quality5 6.
Another major advantage of magnesium glycinate is its excellent digestive tolerance. Unlike some magnesium forms that may cause loose stools or stomach discomfort, magnesium glycinate is generally considered one of the gentlest forms available, making it well suited for regular daily use.
For individuals looking for a highly absorbable, well-tolerated magnesium supplement suitable for everyday use — particularly for sleep and relaxation support — magnesium glycinate is often considered one of the best all-round choices available.
However, not all magnesium glycinate supplements are created equal.
Many magnesium glycinate supplements sold in the UK are “buffered”, meaning they are blended with magnesium oxide — a cheaper and poorly absorbed form often used to artificially increase the amount of elemental magnesium listed on the label.
For this reason, choosing a fully-chelated, non-buffered product, such as our MAGSUPPS magnesium glycinate, is often considered the better option for absorption, quality, and digestive tolerance.
2. Magnesium Citrate
Best for: Energy production, muscle function, and general magnesium supplementation.
Magnesium citrate is another popular and widely used form of magnesium due to its high absorption and versatility. It combines magnesium with citric acid, the natural compound found in citrus fruits, which helps improve the solubility and absorption of magnesium within the body.
Because of its excellent bioavailability, magnesium citrate is commonly used as a general-purpose magnesium supplement to support healthy magnesium levels and the broad benefits associated with magnesium, particularly energy and muscle function.
Citric acid also plays a role in cellular energy production through the Krebs cycle7, which is why magnesium citrate is often associated with energy and overall vitality.
Magnesium citrate is sometimes criticised for causing diarrhoea or digestive discomfort, but this is often misunderstood.
In the United States, high-dose liquid magnesium citrate products are commonly sold and used specifically as laxatives or bowel preparation products. These formulations can provide extremely large doses of magnesium — often between 1,885mg and 2,900mg per serving — far exceeding standard supplemental doses such as the NHS daily recommendations of 270mg for women and 300mg for men.
At standard supplemental doses, however, magnesium citrate is generally well tolerated by most people and remains one of the most widely used and effective forms of magnesium available.
For individuals looking for a highly absorbable, well-rounded magnesium supplement suitable for general daily use, magnesium citrate is also considered one of the best all-round options available.
3. Magnesium Malate
Best for: Energy production, muscle function, exercise recovery, and general magnesium supplementation.
Magnesium malate is a highly bioavailable form of magnesium, combining magnesium with malic acid, a compound naturally found in fruits such as apples and pears. Research suggests that magnesium malate may outperform other magnesium forms, including magnesium citrate, in terms of absorption8.
Malic acid plays an essential role in cellular energy production, particularly through the Krebs cycle9, where the body converts food into usable energy (ATP). Studies also suggest that malic acid may help support athletic performance and recovery after exercise10, making magnesium malate particularly popular among physically active individuals.
Likewise, magnesium itself contributes to normal muscle function, reduction of tiredness and fatigue, and normal energy-yielding metabolism. Research has also shown that magnesium supplementation may help support physical performance in athletes11.
With the overlapping benefits of magnesium and malic acid, magnesium malate is often considered an excellent option for athletes or individuals looking to support both energy and muscle function. Its high bioavailability also makes it well suited for general magnesium supplementation.
4. Magnesium Taurate
Best for: Heart health, relaxation, and general magnesium supplementation.
Magnesium taurate is another gentle, highly bioavailable form of magnesium that combines magnesium with taurine, one of the most abundant amino acids found in the human body. Unlike amino acids primarily used to build proteins, taurine plays important roles in various physiological functions12 and is found in particularly high concentrations in the heart, brain, eyes, and muscles13.
What makes magnesium taurate particularly unique is the taurine component. Taurine has been studied for its potential calming effects on the nervous system, with research suggesting it may help support relaxation by interacting with GABA14, the body’s primary inhibitory neurotransmitter responsible for helping regulate neural activity and excitability within the brain.
Because of this combination, magnesium taurate is often associated with relaxation, nervous system support, and cardiovascular health. Both magnesium and taurine play important roles in normal muscle and nervous system function, which has made magnesium taurate one of the more popular forms for individuals looking to support calm, relaxation, and overall wellbeing.
Like magnesium glycinate, magnesium taurate is also generally considered gentle on digestion and well suited for regular daily supplementation.
5. Magnesium L-threonate
Best for: Cognitive function, focus, brain health, relaxation, and sleep.
Magnesium L-threonate is a specialised form of magnesium created by combining magnesium with threonic acid, a metabolite of vitamin C. What sets it apart from other magnesium forms is its unique ability to cross the blood–brain barrier, allowing it to deliver magnesium directly to the brain15.
This is significant because many traditional magnesium forms, while highly absorbable within the body, have limited ability to increase magnesium levels within brain tissue itself. Magnesium L-threonate was specifically developed to address this and remains one of the few magnesium forms designed to target cognitive function.
Developed by Dr. Guosong Liu, a former MIT professor, magnesium L-threonate is sold under the patented ingredient name Magtein®, which has also recently received novel food authorisation in the UK, allowing it to be legally sold following safety assessment by the FSA.
In a landmark human clinical study16, magnesium L-threonate supplementation was associated with significant improvements in several measures of cognitive function, including attention, working memory, processing speed, and executive function. Notably, participants also demonstrated measurable improvements in functional brain age over the course of the trial.
Further research has also explored magnesium L-threonate’s potential role in supporting relaxation and sleep quality17, with findings suggesting that increasing magnesium levels within the brain may help support relaxation and improve sleep quality in some individuals.
It’s important to understand that magnesium L-threonate is not designed to be a high-strength, general magnesium supplement. Instead, it is a more specialised form aimed specifically at supporting brain health and cognitive function.
For this reason, magnesium L-threonate supplements typically provide a lower amount of elemental magnesium than many other forms — usually around 114 mg per day — as the compound is designed primarily to target the brain rather than maximise total magnesium intake throughout the body.
For individuals specifically interested in magnesium supplementation aimed at cognitive function, focus, relaxation, and sleep, magnesium L-threonate is often considered one of the most specialised and research-backed magnesium forms available.
One Type to Avoid: Magnesium Oxide
Magnesium oxide is one of the most commonly used forms of magnesium in supplements, largely because it is cheap to manufacture and contains a very high amount of elemental magnesium.
However, despite containing around 60% elemental magnesium, studies suggest that only about 4% is absorbed by the body18, making it one of the least bioavailable forms of magnesium available.
One of magnesium oxide’s most well-known effects is its osmotic action in the intestines. It works by drawing water into the digestive tract, which helps soften stool and stimulate bowel movements. Because of this mechanism, magnesium oxide has long been used as a natural laxative to help relieve occasional constipation, and it is widely used for this purpose in clinical practice. In Japan alone, it has been estimated that around 10 million patients are treated with magnesium oxide for constipation each year19.
Due to these properties, magnesium oxide is commonly used in digestive cleanse and colon support supplements designed to promote regular bowel movements and digestive comfort.
While magnesium oxide can be effective for digestive support, it is generally not considered one of the best options for raising magnesium levels within the body due to its relatively poor absorption. For general magnesium supplementation, more bioavailable forms such as magnesium glycinate, citrate, and malate are often preferred.
How to Choose the Best Magnesium Supplement
With so many magnesium supplements available in the UK, choosing the right product can feel overwhelming.
Understanding what to look for can help you choose a magnesium supplement that is effective, high-quality, and well formulated.
1. Choose the Right Type of Magnesium
As discussed in the previous sections, different forms of magnesium can vary in their absorption, digestive tolerance, and intended use. Some forms are better suited for relaxation and sleep, while others may be more appropriate for energy production, muscle function, cognitive support, or general daily supplementation.
It’s also worth noting that different magnesium forms can work well together, offering complementary and synergistic benefits.
One popular combination is magnesium glycinate, malate, and citrate — as found in our MAGSUPPS Triple Magnesium Complex — which is designed to provide excellent absorption alongside the broad, all-round benefits associated with magnesium supplementation.
Another popular combination is magnesium glycinate, taurate, and L-threonate — such as in MagTech — which is more specifically formulated towards relaxation, sleep, and cognitive support.
Choosing a magnesium form aligned with your individual health goals can help you get the most benefit from supplementation.
2. Avoid Buffered Magnesium Supplements
Many magnesium supplements sold in the UK are “buffered”, meaning they blend a higher-quality magnesium form — such as glycinate or taurate — with magnesium oxide, a cheaper and poorly absorbed form often used to artificially increase the amount of elemental magnesium listed on the label.
For this reason, choosing a fully chelated, non-buffered magnesium supplement is often considered the better option for absorption, quality, and digestive tolerance.
Learn more about buffered vs non-buffered magnesium.
3. Check the Manufacturing & Ingredient Quality
High-quality magnesium supplements are typically manufactured in highly regulated regions such as the UK, EU, and USA, in facilities operating to recognised standards such as GMP, HACCP, and ISO certification.
It’s also worth paying attention to the overall formulation. Some supplements contain unnecessary fillers, binders, artificial additives, or flow agents that serve little functional purpose beyond manufacturing convenience.
With modern manufacturing technology, clean, filler-free magnesium supplements should increasingly be considered the standard rather than the exception.
4. Check for Third-Party Lab Tests
Third-party lab testing can help verify the quality, purity, and safety of a magnesium supplement. This may include testing for heavy metals, microbial contamination, and ingredient potency to ensure the product matches what is stated on the label.
Brands that openly share third-party test results often demonstrate a stronger commitment to transparency, quality control, and consumer trust.
5. Look for Brand Reputation & Customer Reviews
Brand reputation and customer reviews can often provide valuable insight into the real-world quality and effectiveness of a magnesium supplement.
When researching a product, it can be helpful to look for consistently positive feedback relating to the specific health benefits you’re looking for, ingredient quality, and overall customer experience. Verified reviews, transparent communication, and a strong brand reputation can all be good indicators of a trustworthy supplement company.
Explore Our Magnesium Supplements
At MAGSUPPS, we specialise in magnesium supplements for the UK market. All our supplements are produced locally using fully chelated, non-buffered magnesium ingredients — free from magnesium oxide, fillers, and unnecessary additives — and independently third-party tested for purity and potency you can trust.
Below is an overview of or best-sellers.
MAGSUPPS Triple Magnesium Complex
For those looking to support their daily magnesium intake, a supplement combining multiple well-absorbed forms offers a practical and well-rounded approach.
MAGSUPPS Triple Magnesium Complex was developed with this in mind — providing a 100% pure blend of three highly bioavailable, complementary forms: magnesium glycinate, malate, and citrate.
Each 3-capsule serving delivers 300mg of pure elemental magnesium, evenly distributed across all three forms, with no fillers or unnecessary additives.
The most popular combination for all-round daily magnesium support — and a great starting point for anyone beginning their magnesium journey.
MAGSUPPS Magnesium Glycinate
For those looking to support sleep, relaxation, or everyday magnesium intake — particularly if other forms have been hard on your stomach — magnesium glycinate is consistently one of the most recommended forms available.
MAGSUPPS Magnesium Glycinate was formulated with this in mind — providing 100% pure, fully chelated, non-buffered magnesium glycinate, free from magnesium oxide, fillers, and unnecessary additives.
Each vegan-friendly capsule delivers 100mg of elemental magnesium, with flexible dosing of 1–3 capsules per day to suit your individual needs. 90 capsules per pouch.
The Bottom Line
Not all magnesium supplements are created equal.
Different magnesium forms vary significantly in their absorption, digestive tolerance, and intended use — which is why choosing the right form of magnesium can make a meaningful difference to your overall experience and results.
For most people, highly bioavailable forms such as magnesium glycinate, citrate, malate, taurate, and L-threonate are generally considered the best options depending on their individual health goals, while poorly absorbed forms such as magnesium oxide are often less suitable for general magnesium supplementation.
When choosing a magnesium supplement, it’s also worth paying attention to formulation quality. Fully chelated, non-buffered magnesium supplements are often considered the better option for absorption and digestive tolerance.