September 29, 2025, 9:00 am | Read time: 6 minutes
Magnesium is one of the essential minerals without which hardly anything functions in the human body. It supports energy metabolism, strengthens muscles and bones, promotes heart health, and is partly responsible for hormonal balance. However, diet alone is not always sufficient to meet the need. This is why athletes or people with certain conditions often turn to dietary supplements. But not all magnesium is the same–choosing the right supplement can be tricky. Read here to find out what to look for and which products perform well in tests.
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Take Warning Signs Seriously: Symptoms of a Deficiency
Magnesium deficiency often goes unnoticed for a long time–initial signs like muscle twitches or cramps, especially in the calves, are often dismissed as harmless. However, fatigue, sleep problems, headaches, irritability, heart palpitations, digestive issues, and inner restlessness can also indicate a low magnesium level. Chronic deficiency can have serious consequences–from DNA damage to an increased risk of dementia.
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Sports, Stress, Pregnancy: When the Need Increases
An increased need for magnesium primarily affects athletes, as they lose more magnesium through sweating. According to experts, the daily requirement for physically active individuals can increase by up to 20 percent. An increased need can also exist during pregnancy, chronic stress, or certain illnesses. Supplementation not only aids in recovery but can also prevent muscle cramps. It is best taken in the evening or directly after training.
Daily Recommendation and Natural Sources
According to the German Nutrition Society, the recommended daily intake is 300 milligrams for women and 350 milligrams for men. Foods particularly rich in magnesium include sunflower and pumpkin seeds, almonds, whole grain products, legumes, green leafy vegetables, and magnesium-rich mineral water.1
Not All Magnesium Is the Same: Which Form Is Sensible?
Magnesium supplements differ not only in their dosage but especially in the compound in which the magnesium is present. Terms like “Magnesium Complex” are often used in marketing–these usually contain various forms such as citrate, bisglycinate, or oxide.
It’s important to know: Organic compounds like magnesium citrate or bisglycinate are absorbed by the body much better than inorganic ones like magnesium oxide. Although the latter contains more elemental magnesium, its bioavailability is lower–less than ten percent, according to a common assumption. While there are studies suggesting therapeutic equivalence, it is undisputed that magnesium oxide mostly remains in the intestines, can bind water, and thus cause digestive issues like bloating or diarrhea.
Organic compounds like citrate or bisglycinate perform significantly better in terms of absorption. Even if the milligram number on the packaging appears lower, ultimately more usable magnesium reaches the body–especially relevant in cases of acute deficiency or increased physical stress.
A study by the University of Isabel I (Burgos) and the CINUSA Research Center (Madrid) also confirms: “Organic magnesium compounds like citrate or bisglycinate tend to be more bioavailable than inorganic forms like magnesium oxide.” The researchers also emphasize that the form of administration and dosage affect absorption–effervescent tablets or granules are superior to traditional tablets. Differences between magnesium forms are particularly relevant for older or sick individuals, while healthy people can meet their needs with any supplement.2
Recommended Products in Comparison
Natural Elements Magnesium Complex
This product is currently the best-selling magnesium supplement on Amazon. It combines five different magnesium compounds–including both organic and inorganic–and provides 400 milligrams of elemental magnesium per daily dose (two capsules). The broad mix is advantageous, utilizing different absorption pathways in the body. The capsules are lab-tested and free from additives.
Note: The included magnesium oxide can cause stomach issues if overdosed. A bottle with 180 capsules lasts about three months.
Igennus Triple Magnesium Complex
The daily dose (two tablets) contains 262 milligrams of elemental magnesium, exclusively in well-bioavailable organic forms: citrate, bisglycinate, and taurate. The combination is particularly stomach-friendly and suitable for those concerned about tolerance. The 60 tablets last for one month. Natural Elements is part of the Natsana Group, which is currently being acquired by Bayer.
Wehle Sports Magnesium Complex
Three capsules per day provide 375 milligrams of elemental magnesium in the forms of citrate, bisglycinate, and malate–all organic compounds with high bioavailability. The combination is also well-tolerated by sensitive individuals. The package with 180 capsules lasts for two months. Wehle Sports is the private label of FNW International from Horb am Neckar.
Raab Vitalfood Magnesium Citrate Powder
The powder consists of 100 percent magnesium citrate and provides about 250 milligrams of elemental magnesium per daily dose (3 grams). The powder form allows for flexible dosing, which is especially beneficial for athletes. Drawback: The sour taste is not to everyone’s liking, and dosing requires some care. Raab Vitalfood is a Bavarian family business based in Rohrbach an der Ilm.
Feel Natural Magnesium
One capsule contains 664 milligrams of magnesium compound, of which 400 milligrams are elemental magnesium–almost exclusively in the form of magnesium oxide. The high number on the label initially seems convincing, but due to the low bioavailability, a large portion remains unused. Additionally, magnesium oxide can cause digestive issues in sensitive individuals. The product is very inexpensive at around 18 euros for a whole year, but it is of lower quality. Feel Natural is also part of the Natsana Group, currently being acquired by Bayer.
What Are the Different Forms of Magnesium and How Do They Work?
Should You Take Magnesium Before or After Exercise?
What You Should Generally Consider When Buying
Dietary supplements are not medications and cannot treat diseases. Therefore, quality takes precedence. Caution is advised, especially with high-dose or extremely cheap products from uncertain sources. Experts recommend starting with a low dose and watching for possible side effects.
The combination with other nutrients should also be considered. Calcium and magnesium, for example, can interfere with each other’s absorption–as can iron and zinc. If medications like antibiotics or thyroid medications are taken, a gap of at least two to three hours is recommended.
Conclusion: Prefer High-Quality Supplements
Magnesium plays a central role in numerous bodily functions and can protect against serious diseases. Those using dietary supplements should focus on high-quality, well-bioavailable compounds like citrate, bisglycinate, or malate. The correct dosage is also important–not too much and not too little. If in doubt, consult a doctor, pharmacist, or nutritionist.