Which magnesium supplement should I take? Everything you need to know about magnesium bisglycinate and other forms

It is one of the most essential minerals the human body needs for proper functioning, supporting:

1. Metabolism and energy production, by facilitating chemical reactions.
2. The musculoskeletal system, by actively participating in muscle recovery after exercise and in bone strength.
3. The nervous system, by helping to reduce intense stress and promote healthy sleep.
4. It supports adequate production of neurotransmitters, particularly serotonin, helping to keep our mood elevated.

Which magnesium supplement should I take? Magnesium bisglycinate and its benefits.

With a simple online search or a visit to a dietary supplement store or pharmacy, our options for magnesium supplements are constantly expanding. Each magnesium supplement contains a different amount of elemental magnesium and is combined with a different chemical compound, resulting in different forms of magnesium.

One of the key factors, regarding supplement absorption and effectiveness, is this chemical compound, which can be organic or inorganic, such as glycine, malic acid, or citric acid. The “combination” of elemental magnesium and two glycine molecules creates the well-known magnesium bisglycinate, which is one of the best-tolerated and most readily absorbed forms of magnesium on the market.

Gastrointestinal tolerance & increased bioavailability. To reap the benefits of a magnesium supplement, certain key conditions must be met. One of the most fundamental is the absorption and utilization of magnesium (or bioavailability), as well as the amount of elemental (“pure”) magnesium, provided by the supplement in question. The superiority of magnesium bisglycinate lies in the presence of the amino acid glycine, which facilitates the transport and absorption of elemental magnesium, into target tissues while minimizing the likelihood of side effects, unlike other forms of magnesium, such as citrate, making it an ideal choice for people with gastrointestinal disorders or irritable bowel syndrome (IBS), as well as for those who choose to use the supplement over a longer period of time.

Sleep & Anxiety. Magnesium bisglycinate has begun to be studied for its potential to improve sleep parameters, as well as to reduce intense feelings of anxiety, which can indirectly and significantly disrupt sleep quality. Glycine, very small in size but miraculous in its properties, shows promising results in improving sleep quality parameters, helping to lower body temperature and regulate neurotransmitters. Therefore, the binding capacity of glycine and high bioavailability make magnesium bisglycinate one of the best magnesium supplement options for severe stress and insomnia.

Disclaimer: The largest body of research on glycine and sleep highlights its benefits at a dosage of 3 g of glycine, taken 1 hour before the scheduled bedtime.

Therefore, magnesium bisglycinate, as one of the most easily absorbed forms of magnesium, may be worth trying for:

• People with chronic insomnia.
• People, experiencing severe stress, which may also affect sleep quality.
• People at increased cardiovascular risk.

Magnesium deficiency has been linked to an increased risk of cardiovascular disease, as magnesium contributes to improved endothelial function and helps regulate blood pressure, thereby protecting against atherosclerosis.

• People with diabetes, prediabetes, or metabolic syndrome.

Magnesium supplementation in patients with diabetes appears to increase insulin sensitivity, improving fasting glucose levels and contributing to better glucose utilization in diabetic patients. Furthermore, magnesium appears to reduce markers of inflammation, while simultaneously increasing the body’s antioxidant capacity, contributing to the production of a very powerful antioxidant, glutathione—a fact that is particularly important in diabetes, where severe oxidative stress is observed.

• Osteopenia & osteoporosis.

Adequate magnesium intake plays a crucial role in bone strength. Magnesium is a vital “partner” of vitamin D, as it enhances its functionality—without functional vitamin D, it is difficult for the bones to absorb calcium.

• Fatty Liver & Fibrosis.

Magnesium supplementation may potentially improve liver function in patients with fatty liver, protecting against a possible deterioration in their health.

Besides magnesium bisglycinate, what other forms are there? What do I need to know?

As mentioned above, magnesium bisglycinate is a bioavailable source of magnesium with excellent gastrointestinal tolerance. However, there are many forms of magnesium available on the market, and it’s easy to get confused and not know which one is best to try based on your needs. Let’s look at what you need to know (see table).

Important reminder: Given that the benefits of supplemental magnesium apply to a large proportion of patients with cardiovascular disease, diabetes, and other conditions, we remind you of the importance of consulting with your treating physician regarding any supplement you wish to use.

Magnesium & Muscle Cramps

Muscle cramps are one of the most common reasons people seek out magnesium. Magnesium plays a role in muscle contraction and relaxation, and a deficiency is associated with cramps, particularly in athletes, pregnant women, and people who sweat profusely. For cramps, highly absorbable forms such as magnesium biglycinate or magnesium malate are preferred.

When should magnesium supplements be used with caution?

However, magnesium supplements—like any dietary supplement—have specific contraindications, along with their respective indications. Therefore, extra caution is advised for people with kidney or gastrointestinal disease, as well as those taking antibiotics or diuretics.

How long should I take magnesium?

A reasonable period of time to try magnesium is 2 to 4 months, taking a break after a few months. It’s important to remember that in case of deficiency, the priority is to boost our diet with dietary sources of magnesium, using the dietary supplement as a practical tool to supplement our diet, as intended.

In cases of hypermagnesemia, which can result from excessive magnesium intake, reduced excretion capacity, or uncontrolled use of magnesium supplements—symptoms of toxicity may occur, such as severe diarrhea, bradycardia, and hypotension.

When is the best time to take magnesium?

Considering that one of the potential benefits of magnesium supplementation is maintaining adequate and restful sleep, it makes sense that magnesium supplements should be taken in the evening, before bedtime. However, this applies mainly to citrate and glycinate or biglycinate, while malate and threonate can be taken in the morning, due to their potential effect on energy production.

For better absorption, you can take the supplement on an empty stomach; however, if you experience gastrointestinal discomfort, it is important to take it after a meal to avoid potential discomfort.

In conclusion

With so much information out there about dietary supplements—let alone magnesium —this article serves as a handy guide that focuses on the key benefits, recommended uses, and precautions, so that everyone can choose the right product, based on their own needs. Among the various magnesium supplements, magnesium bisglycinate stands out for its excellent absorption and minimal risk of side effects. However, the dosage and type of magnesium supplement that will be most beneficial for each of us varies depending on individual needs and medical and dietary history, with future scientific data in the upcoming decades shedding more light on personalized dosages and recommendations for magnesium products.

Scientific References

Boyle, N. B., Lawton, C., & Dye, L. (2017). The effects of magnesium supplementation on subjective anxiety and stress—a systematic review. Nutrients, 9(5), 429.

Cepeda, V., Ródenas-Munar, M., García, S., Bouzas, C., & Tur, J. A. (2025). Unlocking the power of magnesium: A systematic review and meta-analysis regarding its role in oxidative stress and inflammation. Antioxidants, 14(6), 740.

Mcauley-October, D. Glycine’s Role in Sleep Enhancement-Clinical Evidence, Mechanisms, and Therapeutic Applications.

Pardo, M. R., Vilar, E. G., Martín, I. S. M., & Martín, M. A. C. (2021). Bioavailability of magnesium food supplements: A systematic review. Nutrition, 89, 111294.

Schuster, J., Cycelskij, I., Lopresti, A., & Hahn, A. (2025). Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nature and science of sleep, 2027-2040.