Magnesium glycinate and magnesium citrate are both highly absorbable forms of magnesium, but they are commonly used for different purposes. Magnesium glycinate is often chosen by people looking to support relaxation, sleep, and gentle digestion, while magnesium citrate is widely used for occasional constipation as well as increasing magnesium intake. The best choice depends on your health goals rather than one form being universally "better."
Walk into almost any health food store and you'll quickly notice something confusing. There isn't just one magnesium supplement.
There are magnesium glycinate capsules, magnesium citrate powders, magnesium oxide tablets, magnesium bisglycinate, magnesium taurate, magnesium L-threonate, and many others.
It's no surprise that one of the most common questions people ask is: "Which magnesium is actually the best?"
The answer isn't as simple as picking one bottle off the shelf.
Magnesium itself is always the same mineral. What changes is the substance it's attached to. That attachment can influence how well the magnesium dissolves, where the magnesium is transported to, how it's tolerated by the digestive system, and the situations where it may be most useful.
Among all the available options, magnesium glycinate and magnesium citrate are two of the most popular, and for good reason. Both are considered well-absorbed forms of magnesium and are commonly recommended by healthcare professionals.
But despite their similarities, they aren't identical.
Magnesium glycinate is commonly chosen as a gentle daily supplement, and a recent randomized controlled trial found that magnesium bisglycinate produced a modest improvement in insomnia severity among adults with poor sleep quality[i].
Magnesium citrate is widely used to relieve occasional constipation[ii] and is absorbed more readily than magnesium oxide in human studies[iii].
In this guide, we'll explain exactly how they compare, where each one shines, and how to decide which may be the better fit for your needs.
What Is Magnesium Glycinate?
Magnesium glycinate is magnesium bound to the amino acid glycine. It is one of the most commonly used forms for everyday magnesium supplementation because it is generally well absorbed and tends to be gentle on the digestive system.
When manufacturers create a magnesium supplement, they don't use pure magnesium in its metallic form. Instead, magnesium is attached to another molecule that helps stabilize it[i].
In magnesium glycinate, that partner is glycine, a naturally occurring amino acid your body uses to build proteins and support many normal biological processes.
This creates what scientists call an organic magnesium salt, which generally dissolves well and is absorbed more efficiently than several inorganic forms.
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].
Magnesium Glycinate at a Glance
- A well-absorbed form of magnesium[iii]
- Generally well tolerated at standard supplemental doses[iv]
- Suitable for daily magnesium supplementation
- Studied for nighttime use, with one randomized trial reporting a modest improvement in insomnia symptoms among adults with poor sleep7
- Unlike magnesium citrate laxative products, magnesium bisglycinate is not primarily used to relieve constipation[v]
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What Is Magnesium Citrate?
Magnesium citrate is magnesium bound to citric acid. It is a well-absorbed form of magnesium[i] and, because it draws water into the intestines through an osmotic effect, it is commonly used to relieve occasional constipation[ii].
Citric acid is a natural compound found in citrus fruits such as lemons and oranges. When magnesium is attached to citrate, the resulting compound dissolves well in water, making it one of the better absorbed forms of supplemental magnesium.
Unlike magnesium glycinate, magnesium citrate has another well-known property. It can increase the amount of water inside the intestines.
For people experiencing occasional constipation, this can help soften stool and encourage normal bowel movements. Because of this effect, magnesium citrate has been used for many years in both dietary supplements and certain over-the-counter laxative products.
At lower supplemental doses, many people tolerate magnesium citrate well.
At higher doses, however, loose stools become much more common[iii]. For some people, that can be helpful. For others, especially those with sensitive digestion, it may be a reason to choose a different form.
Magnesium Citrate at a Glance
· Highly absorbable form of magnesium
· Commonly used to increase magnesium intake
· Frequently chosen for occasional constipation
· May loosen stools at higher doses
· Available in capsules, powders, liquids, and laxative preparations
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The Main Difference Between Magnesium Glycinate and Magnesium Citrate.
The biggest difference between magnesium glycinate and magnesium citrate isn't how much magnesium they contain. It's how the compound they're attached to influences their typical use and digestive effects.
Both forms provide elemental magnesium. Both are considered among the better-absorbed magnesium supplements available. Both can help correct inadequate magnesium intake.
Where they begin to differ is in how they're commonly used.
Magnesium glycinate is generally favored by people looking for a gentle daily supplement with minimal digestive effects, whereas magnesium citrate is more often chosen when someone wants both magnesium supplementation and support for occasional constipation.
Neither form should be viewed as universally superior. Instead, they're simply different tools that may be appropriate for different situations.
Quick Comparison
Feature
Magnesium Glycinate
Magnesium Citrate
Absorption
Excellent
Excellent
Everyday supplementation
Excellent
Excellent
Gentle on stomach
Usually
Usually, but may loosen stools
Supports relaxation
Common choice
Less commonly selected
Occasional constipation
Minimal effect
Commonly used
Higher-dose digestive effects
Usually mild
More likely to cause loose stools
In the next section, we'll look more closely at how these two forms compare when it comes to absorption, one of the most misunderstood topics in magnesium supplementation.
If you missed our first episode on magnesium, click here.
[i] Lindberg JS, Zobitz MM, Poindexter JR, Pak CYC. Magnesium bioavailability from magnesium citrate and magnesium oxide. Journal of the American College of Nutrition. 1990;9(1):48-55. doi:10.1080/07315724.1990.10720349. PMID: 2407766.
[ii] National Institutes of Health, Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals. Updated January 6, 2026.
[iii] zzo AA, Gaginella TS, Mascolo N, Capasso F. The osmotic and intrinsic mechanisms of the pharmacological laxative action of oral high doses of magnesium sulphate: importance of the release of digestive polypeptides and nitric oxide. Magnesium Research. 1996;9(2):133–138. PMID: 8878010.
[i] National Institutes of Health, Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals. Updated January 6, 2026.
[ii] Bannai M, Kawai N. New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep. Journal of Pharmacological Sciences. 2012;118(2):145-148. doi:10.1254/jphs.11R04FM. PMID: 22370659.
[iii] Schuette SA, Lashner BA, Janghorbani M. Bioavailability of magnesium diglycinate vs magnesium oxide in patients with ileal resection. Journal of Parenteral and Enteral Nutrition. 1994;18(5):430–435. doi:10.1177/0148607194018005430. PMID: 7815675.
[iv] Schuster J, Cycelskij I, Lopresti AL, Hahn A. Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nature and Science of Sleep. 2025;17:2027–2040. doi:10.2147/NSS.S524348. PMID: 40918053.
[v] DailyMed. Citroma Magnesium Citrate Liquid: Drug Facts Label. U.S. National Library of Medicine. Updated March 2, 2026.
[i] Schuster J, Cycelskij I, Lopresti AL, Hahn A. Magnesium Bisglycinate Supplementation in Healthy Adults Reporting Poor Sleep: A Randomized, Placebo-Controlled Trial. Nature and Science of Sleep. 2025;17:2027–2040. doi:10.2147/NSS.S524348. PMID: 40918053.
[ii] DailyMed. Magnesium Citrate Oral Solution: Drug Facts Label. U.S. National Library of Medicine. Updated March 2, 2026. The label identifies magnesium citrate as a saline laxative for relief of occasional constipation.
[iii] Lindberg JS, Zobitz MM, Poindexter JR, Pak CYC. Magnesium bioavailability from magnesium citrate and magnesium oxide. Journal of the American College of Nutrition. 1990;9(1):48–55. doi:10.1080/07315724.1990.10720349. PMID: 2407766.