Magnesium is one of the minerals most frequently mentioned in dietary supplements. But on the shelves, you will find magnesium oxide, citrate, malate, glycerophosphate, bisglycinate… These forms are not interchangeable. Their bioavailability, digestive tolerance, and uses vary considerably.
Why is magnesium essential?
Magnesium is involved in more than 300 enzymatic reactions in the body. It contributes to the normal functioning of the nervous system, normal muscle function, the reduction of fatigue, and the maintenance of normal psychological function.
Magnesium deficiency is extremely common. Studies estimate that 70 to 80% of the population does not meet its daily requirements (300–400 mg/day). The causes include a diet low in leafy greens and legumes, high alcohol and caffeine consumption, and chronic stress… which, precisely, accelerates the urinary elimination of magnesium.
The different forms of magnesium compared
Magnesium oxide: the least expensive form, and the most concentrated on paper (60% elemental magnesium), but the least well absorbed (4–0% bioavailability) and often responsible for laxative effects.
Magnesium citrate: better bioavailability than oxide (~30%), with good overall tolerance. It remains an economical option.
Glycerophosphate: excellent absorption, with a neutral effect on bowel function. Often used in medical settings.
Magnesium bisglycinate: magnesium is bound to two molecules of glycine (an amino acid). This chelation significantly improves intestinal absorption, reduces laxative effects, and promotes better digestive tolerance. Glycine itself has relaxing properties on the central nervous system — a valuable synergy in cases of stress or sleep disorders.
Stress and magnesium: a vicious cycle to break
Chronic stress and magnesium deficiency form a well-documented vicious cycle. Stress increases the urinary elimination of magnesium. And a lack of magnesium makes the nervous system more reactive to stress. Supplementing with magnesium bisglycinate helps break this cycle by providing magnesium that is genuinely absorbed by the body.
How to choose the right magnesium
- Choose bisglycinate or glycerophosphate if you have digestive sensitivities or if you take the supplement in the evening.
- Check the amount of elemental magnesium (not just the weight of the salt): the goal is to provide 100–300 mg/day depending on your deficiency.
- The synergy with vitamins B6 and B9 optimizes the cellular use of magnesium.
The Epycure solution
The Cortisol Balance Program contains magnesium bisglycinate (56.25 mg of elemental magnesium per day) combined with KSM-66® Ashwagandha, L-Tryptophan, and B vitamins. Magnesium contributes to the normal functioning of the nervous system and helps reduce fatigue. The bisglycinate form was chosen specifically for its excellent absorption and digestive tolerance, which are particularly important when taken in the evening.
The product FAQ states: “Magnesium bisglycinate is one of the forms most readily absorbed by the body. During prolonged periods of stress, it helps support the nervous system and reduce nervous fatigue by effectively providing the magnesium the body needs.” Made in France, B Corp certified.
In summary
Not all magnesium supplements are equal. If your goal is to support the nervous system, reduce stress-related fatigue, and sleep better, bisglycinate is the form to prioritize — combined with cofactors that enhance its action.
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