Can magnesium glycinate cause diarrhoea or gastrointestinal complaints?
At normal doses (around 5 mg per kilogram of body weight per day) gastrointestinal complaints are not to be expected, but at higher doses a laxative effect is a well-known side effect of oral magnesium.
Magnesium glycinate is known as one of the gentler forms of magnesium for the gut. Whether it causes gastrointestinal complaints depends strongly on the dose. At physiological supplementation of around 5 mg per kilogram of body weight per day, no laxative effects are expected. That amount is described as practically non-toxic, as long as the kidneys are functioning normally.
The tipping point lies at pharmacological doses of more than 10 mg per kilogram of body weight per day. Above that threshold, a laxative effect is a well-known side effect of oral magnesium supplements. How pronounced that effect is varies from person to person and from one form of magnesium to another.
Magnesium glycinate as a specific salt has not been examined in the available studies. What is known about gastrointestinal complaints applies to oral magnesium in general and to other salts such as magnesium chloride and magnesium hydroxide. Whether glycinate behaves in exactly the same way has not yet been directly tested.
If you have kidney problems, extra caution is warranted: with reduced kidney function, magnesium can accumulate and the risks of side effects are greater. In that case, discuss this with your doctor before you start.
The answer is based on one publication describing the threshold values for laxative side effects of oral magnesium, and on a small study with magnesium chloride that found no effect on the gut microbiome. Magnesium glycinate as a specific form has not been separately examined for gastrointestinal complaints in the available sources; the dose thresholds are therefore taken from oral magnesium supplementation in general. The evidence is limited.
What exactly does magnesium glycinate do in your body?
Magnesium glycinate is well absorbed, but for most healthy people it is not demonstrably better than citrate. For those with poor intestinal function or a sensitive stomach, it is a worthwhile choice.
Does magnesium glycinate help you sleep better?
Magnesium may offer some benefit for sleep in certain people who are deficient or have a medical condition, but this has not been demonstrated for healthy people without a deficiency. If you have had poor sleep for years, first discuss with your doctor whether other causes may be involved.
What is the difference between magnesium bisglycinate and magnesium glycinate?
Magnesium bisglycinate and magnesium glycinate are two names for the same supplement. Whether it is absorbed better than magnesium citrate is not yet clear: the studies in healthy people contradict each other, and citrate currently has the strongest evidence base.