Magnesium glycinate vs citrate: what’s the difference?

Magnesium glycinate and magnesium citrate are two commonly used forms of magnesium. They both provide magnesium, but the mineral is combined with a different compound.

Magnesium glycinate — also commonly called magnesium bisglycinate — combines magnesium with glycinate, which comes from the amino acid glycine. Magnesium citrate combines magnesium with citrate.

The difference matters, but the name on the front of a supplement is only part of the comparison. Elemental magnesium, dosage, formulation and individual tolerance are important as well.

Current research also does not support a simple rule that one of these forms is universally better than the other. Magnesium citrate has a relatively established human absorption evidence base. Bisglycinate has also been studied, but direct and comparable evidence between the two remains more limited.

What is the difference between glycinate and citrate?

The main difference is the compound associated with the magnesium.

With magnesium bisglycinate, magnesium is associated with glycinate. With magnesium citrate, it is associated with citrate.

Once you start comparing products, however, a second distinction becomes just as important: compound weight is not the same as magnesium content.

That is where elemental magnesium comes in.

Why does elemental magnesium matter?

A magnesium compound contains more than magnesium alone.

Part of the weight of magnesium bisglycinate comes from glycinate. With magnesium citrate, part comes from citrate.

Elemental magnesium describes the magnesium itself.

The NIH notes that a supplement label reports the amount of elemental magnesium rather than the total weight of the magnesium-containing compound.

So a large number next to “magnesium bisglycinate” or “magnesium citrate” should not automatically be interpreted as the amount of magnesium you are getting.

When comparing two products, elemental magnesium per recommended serving is usually the more useful number.

Are magnesium glycinate and citrate absorbed differently?

The form of magnesium can influence absorption.

According to the NIH, magnesium compounds that dissolve well in liquid tend to be absorbed more completely than less soluble forms. Magnesium citrate is among the forms for which human studies have shown relatively good bioavailability, particularly when compared with magnesium oxide.

The evidence becomes less straightforward when the question is specifically citrate versus bisglycinate.

There are studies involving both forms, but differences in study design, formulation, population and the way magnesium status is measured make a simple head-to-head ranking difficult. A 2024 crossover study, for example, included citrate and bisglycinate among several magnesium sources, but it was primarily designed to evaluate a proprietary microencapsulated magnesium ingredient. The study found a significant plasma-magnesium rise at four hours after citrate but not after bisglycinate; it was also industry-funded and assessed short-term plasma changes rather than establishing a universal hierarchy between conventional forms.

That is useful evidence, but not enough to conclude that citrate is always better than bisglycinate.

What do we know about magnesium citrate?

Magnesium citrate has a relatively substantial human research history.

An older clinical study found citrate to be more soluble than magnesium oxide and to produce a greater increase in urinary magnesium after administration, which the researchers interpreted as greater bioavailability.

Another randomized double-blind study compared citrate, an amino-acid chelate and magnesium oxide in 46 healthy participants. The organic forms showed greater absorption than oxide over the study period, while citrate produced the strongest response on several of the magnesium measures used.

These studies support citrate as a well-studied magnesium form.

They do not establish that citrate outperforms every other magnesium compound under every condition.

What do we know about magnesium bisglycinate?

Magnesium bisglycinate has also been studied in humans, although the absorption literature is smaller.

One randomized crossover study compared magnesium diglycinate with magnesium oxide in twelve people who had undergone ileal resection.

Across the complete group, magnesium absorption was very similar between the two preparations. A subgroup with particularly poor absorption from magnesium oxide absorbed more magnesium from the chelate.

That is interesting evidence for the compound, but the participants had a very specific medical history. It would be inappropriate to turn that result into the general claim that magnesium bisglycinate is always better absorbed.

This is one reason we avoid statements such as “highest bioavailability” unless a claim can actually be supported for the context in which it is being used.

Which is better absorbed: magnesium glycinate or citrate?

There is not enough consistent head-to-head evidence to declare a universal winner.

Citrate has a stronger and more established human absorption evidence base. Bisglycinate also has human evidence behind it, but direct comparisons with citrate are less extensive.

A recent study that included both forms illustrates why a simple ranking is difficult: its results depended on the formulation, measurement method and short observation period, and its primary purpose was to investigate another proprietary magnesium technology rather than settle the citrate-versus-bisglycinate question.

So neither of these statements is well supported as a blanket rule:

“Bisglycinate is always the best-absorbed magnesium.”

“Citrate is always better than bisglycinate.”

The evidence is more nuanced than either claim.

Where does magnesium oxide fit into the comparison?

Magnesium oxide appears frequently in magnesium absorption studies, which makes it a useful reference point.

Compared with citrate, it has produced lower bioavailability measures in several studies. One frequently cited trial found magnesium citrate to be considerably more soluble and to produce a larger urinary magnesium response than magnesium oxide.

That does not mean magnesium oxide cannot supply magnesium.

Research using different measures has not always produced identical results. For example, a randomized crossover study in healthy adults found a greater increase in intracellular magnesium after the oxide preparation than after citrate, although the two preparations also supplied different amounts of elemental magnesium.

That is a useful reminder that “bioavailability” is not a single measurement and study results need context.

For this article, oxide is therefore a reference rather than the main comparison.

Glycinate, citrate and oxide compared

Swipe horizontally to view the full comparison.

Feature Magnesium glycinate / bisglycinate Magnesium citrate Magnesium oxide
Magnesium combined with Glycinate Citrate Oxide
General type Chelated magnesium form Magnesium salt Inorganic magnesium compound
Human absorption research Available, but fewer direct comparisons with citrate Relatively well studied Frequently used as a comparator
Elemental magnesium Depends on the ingredient and product Depends on the ingredient and product Depends on the ingredient and product
Universal best form? Not established Not established No useful universal conclusion

What this table cannot tell you is whether one finished supplement is better than another.

For that, you also need to know the actual dose and complete formulation.

What about tolerance?

Tolerance can vary between people and can also depend on how much supplemental magnesium is consumed.

It is common to see magnesium glycinate marketed as automatically “gentle on the stomach” and citrate described as inherently laxative.

That is too simplistic for a general product comparison.

Different magnesium compounds can have different gastrointestinal characteristics, but dosage, formulation and individual response matter. Marketing shorthand should therefore not replace the information on the actual product or the evidence behind the specific formulation.

For Primal Wolf, we would rather describe what is in a formula than give every magnesium form a predetermined personality.

Which magnesium form is best?

There is no single answer that applies to every supplement.

A more useful comparison looks at several factors together:

  • the amount of elemental magnesium;
  • the magnesium compound used;
  • the recommended daily serving;
  • the complete formulation;
  • the quality of the available evidence;
  • individual tolerance.

This also prevents a common mistake: judging a magnesium supplement by one ingredient name while ignoring everything else on the label.

Do glycinate and citrate make magnesium work differently in the body?

The recognised physiological functions apply to magnesium itself.

Under EU rules, authorised claims include that magnesium contributes to normal muscle function, normal functioning of the nervous system, normal energy-yielding metabolism and normal psychological function, provided the conditions of use for those claims are met.

Those authorised functions do not demonstrate that magnesium bisglycinate supports normal muscle function better than magnesium citrate, or vice versa.

The magnesium compound and the physiological role of magnesium are therefore related questions, but they should not be confused.

Why does Primal Wolf use magnesium bisglycinate?

Primal Wolf Magnesium combines magnesium bisglycinate with vitamin B6. We look at the magnesium form as part of the complete formula rather than as a standalone superiority claim. Current amounts, the daily serving and directions for use are available on the Primal Wolf Magnesium product page.

Frequently asked questions

Is magnesium glycinate the same as magnesium bisglycinate?

The names are commonly used for the same magnesium-glycine compound. “Bisglycinate” gives a more specific description of the compound.

Is magnesium glycinate better than magnesium citrate?

The available evidence does not establish one of the two as universally better. Citrate has a relatively strong human absorption evidence base, while bisglycinate also has human research but fewer directly comparable studies.

Which one is more bioavailable?

There is insufficient consistent head-to-head evidence to assign a universal winner. Study design, formulation, dose and the way magnesium status is measured all influence the result.

Should I compare the number of milligrams on the front of the label?

Not without checking what that number represents. The weight of a magnesium compound and the amount of elemental magnesium are different.

Is magnesium citrate better than magnesium oxide?

Several human studies have found citrate to produce higher absorption-related measures than magnesium oxide, although not every study and measurement method has produced the same pattern.

Learn more

What is magnesium bisglycinate?

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