Magnesium L-Threonate Vs. Magnesium Glycinate: Which Should You Take? A Dietitian Explains

One of the standout benefits of magnesium glycinate is its potential calming effect on the body and mind. Glycine itself acts as a neurotransmitter with calming properties, which may complement magnesium’s ability to help regulate stress and promote relaxation. Many people use magnesium glycinate in hopes that it may help manage feelings of anxiety, reduce stress, and improve sleep quality. Some data suggest that taking it consistently has resulted in improved insomnia severity in adults reporting poor sleep quality and may be linked to improvements in mild anxiety symptoms.

While magnesium glycinate is widely praised, it’s not without a few considerations. For most people, it’s very well tolerated, and side effects are rare, especially compared to other forms like magnesium oxide, which can have a strong laxative effect. However, when taken in very high doses, some individuals might still experience mild digestive upset, such as bloating or loose stools.

The primary limitation of magnesium glycinate is related to its specific strengths. While it provides magnesium to the entire body, including the brain, it doesn’t have the same targeted impact on brain magnesium levels as some other forms, because it does not cross the blood-brain barrier, which is essentially a shield that protects the brain by letting in only what it needs and keeping out harmful stuff. However, some data suggest magnesium glycinate may still help support cognitive health in a roundabout way. Supporting sleep quality and helping reduce symptoms of anxiety, it may create the right conditions for better brain health. Good sleep and lower stress are key to keeping your mind sharp and protecting your brain over time.

Magnesium L-threonate is a newer, patented form of magnesium that has generated a lot of excitement for its unique ability to cross the blood-brain barrier. As mentioned above, this barrier is a protective filter that separates the bloodstream from the brain, and it’s notoriously difficult for many substances to pass through. Magnesium L-threonate, however, is specially designed to effectively penetrate this barrier and increase magnesium concentrations directly in brain cells.

This unique property makes it a go-to supplement for cognitive support. Research suggests that by supporting magnesium levels in the brain, magnesium L-threonate may support learning, memory, and overall brain plasticity, a.k.a. the brain’s ability to adapt and form new connections. It may help enhance both short-term and long-term memory and protect against age-related cognitive decline, but more human clinical trials are needed to confirm this. If your primary focus is on brain health, supporting your mental clarity, or helping keep your cognitive function on target as you age, magnesium L-threonate is an excellent option to explore in conjunction with other factors, like eating a brain health-supporting diet (like the MIND diet), physical activity, and stress management.

The main drawback of magnesium L-threonate is its price. As a patented and specialized form, it is typically more expensive than other types of magnesium, including glycinate. This higher cost might be a barrier for some, especially for long-term use.

Additionally, while it excels at targeting the brain, it may not be the most efficient choice for addressing systemic magnesium deficiencies throughout the rest of the body. It may also cause drowsiness in some individuals, particularly when first starting the supplement. For this reason, it’s often recommended to take it in the evening.

So, how do you choose between these two fantastic options? The answer depends entirely on your personal health goals. There is no single “better” form; there is only the form that is better for you. Both are excellent choices that deliver magnesium effectively, but they shine in different areas.

Choose magnesium glycinate if:

• Your main goal is to promote relaxation, reduce stress, or manage anxiety.
• You are looking to improve your sleep quality.
• You want a highly absorbable, all-purpose magnesium supplement that is gentle on the stomach.
• You are looking for a more budget-friendly option.

Choose magnesium L-threonate if:

• Your primary concern is cognitive health, including memory, focus, and learning.
• You want to support long-term brain health and protect against age-related cognitive decline.
• You are specifically looking to increase magnesium levels in your brain.
• Cost is not a significant factor in your decision.

Ultimately, both magnesium glycinate and magnesium L-threonate offer valuable benefits. By identifying your main reasons for supplementing with magnesium (ideally with your healthcare provider), you can select the form that best aligns with your needs and supports your journey toward better health.

Dietary supplements are products intended to supplement the diet. They are not medicines and are not intended to treat, diagnose, mitigate, prevent, or cure diseases. Be cautious about taking dietary supplements if you are pregnant or nursing. Also, be careful about giving supplements to a child, unless recommended by their healthcare provider.