Understanding the Differences: Magnesium Glycinate vs Bisglycinate

January 6, 2026 •

4 min read

Recent research shows that many supplements labeled as "magnesium glycinate" are, chemically speaking, magnesium bisglycinate, indicating that the terms are often used interchangeably by manufacturers. This widespread practice means the distinctions are primarily in nomenclature and, in some cases, product formulation, rather than significant physiological effects for the consumer.

Quick Summary

Magnesium glycinate and bisglycinate are often the same compound, with 'bisglycinate' being the precise chemical name for magnesium bonded to two glycine molecules. Quality differences depend on whether the product is fully chelated or just a blend, affecting absorption and digestive tolerance.

Key Points

Interchangeable Names: Magnesium glycinate and bisglycinate typically refer to the same compound, with "bisglycinate" being the more precise chemical term.
High Bioavailability: Both forms are highly absorbable due to chelation, meaning they are bonded to the amino acid glycine.
Gentle on Digestion: This chelated structure makes them gentle on the stomach and less likely to cause a laxative effect compared to other forms like magnesium oxide.
Relaxation Benefits: The presence of glycine, a calming amino acid, adds to the supplement's ability to reduce stress and improve sleep quality.
Product Quality Varies: For maximum benefit, look for a supplement explicitly labeled as "fully chelated" or "fully reacted," as some products may be simple, less-effective blends.

The Chemical and Naming Distinctions

At the core, the main point of confusion lies in the naming convention. Magnesium bisglycinate is the more scientifically accurate name for the compound where one magnesium ion is chelated (bonded) with two glycine molecules. The prefix "bis-" signifies "two." Magnesium glycinate, on the other hand, is the more common and simplified marketing term for this same product. For the majority of reputable supplements, these two names refer to the identical compound: a highly bioavailable, chelated form of magnesium that is gentle on the digestive system.

However, a crucial point of differentiation can exist in the product's manufacturing process and purity. Some lower-quality brands may market a product as "magnesium glycinate" when it is merely a blend of magnesium and glycine that is not fully chelated. A truly chelated supplement, like magnesium bisglycinate, offers better stability and absorption. This chelation process protects the mineral from interfering with other compounds in the digestive tract, ensuring more of it is absorbed and utilized by the body. For consumers, checking a product label for terms like "fully reacted" or "chelated" can help ensure a high-quality supplement.

Bioavailability and Digestion

Both magnesium glycinate and bisglycinate are well-known for their high bioavailability and superior digestive tolerance compared to less absorbable forms like magnesium oxide. This is because the chelated structure allows the magnesium to pass through the intestinal wall more easily without causing the laxative effect associated with other magnesium salts. The presence of glycine, an inhibitory neurotransmitter, also provides an added benefit of calming effects on the nervous system, which is why these forms are popular for promoting relaxation and sleep.

In some discussions, magnesium bisglycinate is cited as having a slight edge in absorption due to the presence of two glycine molecules. While this may technically be a chemical distinction, many sources confirm that for practical consumer purposes, the absorption and effects are largely the same, provided both are high-quality, fully chelated products. The key determinant is the overall quality and purity of the supplement, rather than the specific "glycinate" or "bisglycinate" name.

Comparison of Magnesium Forms


Feature	Magnesium Bisglycinate/Glycinate	Magnesium Citrate	Magnesium Oxide
Primary Use	Relaxation, sleep, muscle function, anxiety	Constipation relief, general supplementation	Heartburn, short-term constipation
Bioavailability	High; well-absorbed due to chelation	Good; better than oxide, but less stable than bisglycinate	Poor; less than 4% absorbed
Digestive Impact	Very gentle; minimal laxative effect	May cause laxative effects at higher doses	Can cause significant gastrointestinal distress and diarrhea
Glycine Benefit	Includes calming effects from glycine	Not bound to glycine; no calming effect from glycine	No calming effects from glycine
Cost	Often more expensive due to chelation process	Generally affordable and widely available	Inexpensive, but requires higher dosage for absorption

Choosing the Right Supplement

When navigating the choice between magnesium glycinate and bisglycinate, the primary factors to consider are product quality and your specific health goals. For individuals prioritizing high absorption and minimal digestive impact for relaxation, sleep, or muscle recovery, a fully chelated magnesium bisglycinate is the ideal choice. Conversely, if you are simply looking for an affordable, general magnesium supplement and are not sensitive to digestive issues, other forms like magnesium citrate might be considered, though they do not offer the added calming effects of glycine.

Regardless of the name on the bottle, verifying that the product is a fully chelated form is the most important step for maximizing benefits. A high-quality magnesium bisglycinate will provide the most reliable results for stress reduction, improved sleep quality, and overall magnesium replenishment. If you are new to supplements, starting with a lower dosage and monitoring your body's response is recommended. Consulting a healthcare professional can also help tailor your supplementation strategy to your unique needs.

Conclusion

In summary, the difference between magnesium glycinate and bisglycinate is largely a matter of terminology rather than significant chemical or functional variation, provided the product is a high-quality chelated form. Both are prized for being highly bioavailable and gentle on the stomach. The name "magnesium bisglycinate" is the more precise chemical description, indicating one magnesium ion bound to two glycine molecules. This chelated structure is what ensures superior absorption and tolerance compared to non-chelated varieties. For consumers, the best approach is to focus on finding a reputable brand that explicitly states its magnesium is fully chelated to receive the calming, muscle-relaxing benefits associated with this popular supplement.

Authoritative Source

One authoritative source on the topic of magnesium forms and absorption is the National Institutes of Health. Their Office of Dietary Supplements provides detailed fact sheets on magnesium, discussing its functions, food sources, and different supplement forms available. The NIH highlights the varying bioavailability among different magnesium compounds and the importance of chelation for enhanced absorption. This resource serves as a reliable basis for understanding why chelated forms like glycinate/bisglycinate are often recommended. National Institutes of Health Fact Sheet

Frequently Asked Questions

For most reputable supplement brands, yes, they are the same product. The name 'bisglycinate' is the more chemically accurate term for magnesium chelated with two glycine molecules, but 'glycinate' is the more common marketing name used interchangeably.

Some manufacturers prefer the term 'bisglycinate' to emphasize the full chelation with two glycine molecules, which can slightly enhance stability and absorption. It serves as a quality indicator, differentiating it from potentially less pure blends simply called 'glycinate'.

No, there is generally no difference in side effects. Both forms are known for being very gentle on the stomach and are far less likely to cause digestive issues like diarrhea compared to forms like magnesium citrate or oxide.

Both forms are excellent for sleep and relaxation due to the combination of magnesium's muscle-calming effects and glycine's calming effect on the nervous system. Because they are typically the same compound, the benefits for sleep are identical for high-quality, fully chelated products.

No, the name itself does not affect absorption. What matters is the quality of the product and whether it is a fully chelated form. A high-quality supplement labeled 'glycinate' will have the same absorption as a 'bisglycinate' product of equal quality.

Look for specific wording on the label, such as "fully reacted," "fully chelated," or "magnesium bisglycinate chelate." You can also check the ingredients list to ensure it's not a mixture of magnesium oxide and glycine.

For general supplementation, either a high-quality magnesium glycinate or bisglycinate is an excellent choice. Both offer superior absorption and digestive comfort, making them ideal for replenishing magnesium levels effectively.