Magnesium Knowledge Centre — Magnesium

When comparing magnesium supplements, many people focus on one question: "Which form absorbs best?" The answer is more complicated than simply choosing the form with the highest number on the label. Magnesium supplements do not enter the body as free magnesium metal. Instead, magnesium is provided as part of a compound that must dissolve in the digestive tract before the mineral can be absorbed.

Mistake #1: Choosing the Highest Dose Because More Seems Better A higher dose doesn’t automatically provide greater benefits. The body regulates magnesium absorption and balance, meaning increasing the amount consumed does not always lead to a proportional increase in magnesium available for use. A dose that can be taken consistently is often more practical than a higher dose that causes digestive discomfort.

There is currently no strong evidence showing that magnesium must be taken at a specific time of day to work better. Unlike medications that may require precise timing to reach a specific blood concentration, magnesium is a dietary mineral that supports ongoing physiological processes. The body carefully regulates magnesium levels through absorption, storage, and kidney excretion[2]. For this reason, the “best” time often comes down to personal preference and consistency.

Because magnesium glycinate usually causes fewer digestive side effects than some other forms, it has become a popular choice for people who want to increase their magnesium intake over the long term. Many people also choose magnesium glycinate as part of their evening routine because magnesium plays a role in normal muscle and nerve function4, while glycine itself has been studied separately for its role in supporting healthy sleep[ii].