Magnesium is a mineral that’s involved in over 300 reactions in the body. It’s important for muscle contraction, heart rhythm, and energy production.

Magnesium bisglycinate is a dietary supplement made of magnesium that’s chelated, or bound to, the amino acid (protein building block) glycine. It’s more readily absorbed in the intestines than other forms of magnesium. Available in capsule and powder forms, it’s been studied to treat pregnancy-induced leg cramps and aid in muscle recovery.

Here’s what you need to know about this form of magnesium, including its benefits and risks.

Nutrition

While magnesium bisglycinate can’t be obtained through the diet, elemental magnesium can be. Foods rich in magnesium include the following:

• Seeds, like pumpkin and chia
• Nuts, like almonds, cashews, and peanuts
• Spinach
• Soy milk
• Black beans

Whole foods are the best sources of magnesium. Processed foods are typically low in magnesium, and cooking or boiling produce also reduces amounts.

The Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies recommends adults get between 310 and 420 mg of magnesium daily, either through foods or dietary supplements. Here are the specific recommendations.

Uses

In general, magnesium supplements have shown benefits for conditions such as:

There’s not much research regarding magnesium bisglycinate itself, though. It’s been studied in humans for leg cramps and in vitro (test tube) studies to improve muscle recovery.

Here’s what you need to know about the evidence supporting magnesium bisglycinate.

Pregnancy-Induced Leg Cramps

Magnesium bisglycinate has been studied in a clinical trial of 80 pregnant females with leg cramps at least twice a week.

Taking magnesium bisglycinate daily for four weeks reduced both the cramps’ frequency and intensity versus the placebo (an inactive substance given to control groups). 86% of those who took magnesium had at least a 50% decrease in cramp frequency. Almost 70% had a 50% reduction in cramp intensity.

Because this was a small study, more data is needed before magnesium bisglycinate can be routinely recommended for leg cramps.

Muscle Recovery

Magnesium is essential for muscles to contract and relax and can improve exercise performance.

Magnesium bisglycinate is a trendy workout supplement, but there’s very little evidence of benefit for this particular form of magnesium.

It’s been studied in skeletal muscle cells (in vitro) for muscle recovery. A few caveats: test tube trials don’t offer as much information as human studies. And magnesium bisglycinate was part of a combination that included vitamin D, curcumin, and potassium citrate. That said, the combination helped the muscle cells during normal conditions and those that imitated strenuous exercise.

More robust human clinical trials are needed before magnesium bisglycinate can be recommended for athletic performance or to aid muscle recovery after a workout. Studies in humans and trials of magnesium alone rather than as part of a combination product are required to better determine its effect on the muscles.

Dosage

Magnesium bisglycinate was studied at 300 mg daily for four weeks for leg cramps during pregnancy.

Safety

To avoid or treat adverse events, take the following safety precautions:

• Avoid magnesium bisglycinate if you’re allergic to it or its components (parts).
• Seek immediate medical attention if you have a severe allergic reaction (itching, hives, shortness of breath).

Side Effects

Magnesium bisglycinate seems to be better absorbed in the intestines than other forms of magnesium, and it may cause fewer side effects. There isn’t much data on its side effect profile, however.

Elemental magnesium typically causes gastrointestinal side effects such as:

These side effects are due to magnesium’s relaxing effect on the muscles of the intestines.

In a clinical trial studying its effects on people assigned female at birth, magnesium bisglycinate caused nausea in 25% of those who took it and diarrhea in 14%.

Though rare, taking too much magnesium can cause side effects like the following:

Interactions

Many medications can cause low magnesium levels or make magnesium supplements less effective. Some common ones include:

Other medications used for mood regulation, like lithium and antidepressants, can increase magnesium levels.

Precautions

Do keep the following precautions in mind when using magnesium bisglycinate:

• Pregnancy: Magnesium requirements increase during pregnancy. Magnesium supplements are likely safe during this time, but discuss their use with your healthcare provider to ensure safety.
• Nursing: Magnesium is likely safe while breastfeeding. Discuss its use with your healthcare provider to ensure safety.
• Children: Some forms of magnesium have been studied for children with diabetes, asthma, and attention deficit hyperactivity disorder (ADHD). According to the FNB, depending on your children’s age, they may need between 130 mg and 410 mg of magnesium daily. The effects of magnesium bisglycinate specific to children have not been studied. Consult your child’s pediatrician before beginning this or any other supplement.
• Other conditions: People with kidney failure should be cautious when taking magnesium products as they could cause heart block or magnesium toxicity.

Similar Supplements

Other supplements that have been studied for leg cramps include:

Some other supplements that may help muscle recovery after workouts are:

Summary

Magnesium bisglycinate is a dietary supplement made of magnesium and glycine. It is effective for pregnancy-induced leg cramps according to one clinical trial, but more research is needed before it can be routinely recommended.

Side effects typically affect the gastrointestinal system. These may be less frequent with magnesium bisglycinate as opposed to other forms of magnesium. For guidance on how to choose the right magnesium supplement for you, consult with your healthcare provider, pharmacist, or registered dietitian.