Yes, Is There Glycine in Collagen Supplements? The Full Explanation

November 18, 2025 •

4 min read

Glycine, the simplest amino acid, is the most abundant amino acid found in collagen, making up roughly one-third of its structure. This confirms that yes, there is glycine in collagen supplements, and it is fundamental to the protein’s structure and function.

Quick Summary

Collagen supplements contain high levels of glycine, the primary amino acid essential for building collagen's triple-helix structure and for numerous bodily functions. It's a key reason for collagen's health benefits.

Key Points

Yes, there is glycine in collagen supplements: Glycine is the most abundant amino acid in collagen, comprising roughly one-third of its total structure.
Glycine is essential for collagen's structure: Its small size is crucial for forming the tight triple-helix that gives collagen its strength.
Collagen provides more than just glycine: Supplements offer a broad spectrum of amino acids, whereas a pure glycine supplement provides only one.
Glycine supports sleep and antioxidant production: Beyond its structural role, glycine helps produce glutathione and can improve sleep quality.
Hydrolyzed collagen enhances absorption: Most supplements are broken down into easily digestible peptides, making the glycine readily available to the body.
Natural sources include bone broth and meat: High-collagen foods like bone broth, chicken skin, and certain meat cuts are rich natural sources of glycine.

The Fundamental Relationship: Glycine and Collagen

To understand the link between glycine and collagen supplements, one must first grasp the core composition of collagen itself. Collagen is the most abundant structural protein in the body, providing strength and elasticity to skin, bones, tendons, and cartilage. The remarkable properties of collagen are dependent on its unique structure, a triple helix formed from three polypeptide chains.

The building blocks of these chains are amino acids, with glycine playing a uniquely significant role. Its small size allows the chains to twist into the tight triple-helix formation, and it appears at every third position in the amino acid sequence (e.g., glycine-proline-X). In fact, approximately one-third of the amino acid content of collagen is glycine. This makes any product containing true collagen, including supplements, a rich source of this vital amino acid.

Glycine's Critical Functions Beyond Structure

While glycine is indispensable for collagen formation, its benefits extend far beyond its structural role. When you consume a collagen supplement, your body breaks down the protein into peptides and free amino acids, including a significant amount of glycine, which can be used for a variety of purposes.

Key functions of glycine include:

Antioxidant Production: Glycine is one of the three amino acids required to produce glutathione, a powerful antioxidant that protects cells from oxidative stress and free radical damage.
Sleep Quality: Studies have shown that supplementing with a few grams of glycine before bed can improve sleep quality, help you fall asleep faster, and reduce daytime sleepiness.
Creatine Synthesis: The body uses glycine, along with two other amino acids, to form creatine, which provides energy to muscles and supports brain function.
Nerve Function: Glycine acts as an inhibitory neurotransmitter in the central nervous system, helping to calm the brain and potentially improving mood and cognitive function.
Joint and Muscle Health: By supporting the repair of connective tissues and acting as an anti-inflammatory, glycine contributes to overall musculoskeletal health.

Is Supplemental Glycine Necessary with Collagen?

This is a common question, and the answer depends on your specific health goals. Since collagen supplements are inherently packed with glycine, many people may find that their collagen intake sufficiently boosts their glycine levels. However, supplementing with pure glycine alongside collagen is generally considered safe and may offer synergistic benefits for certain conditions.


Feature	Collagen Supplement	Glycine Supplement
Primary Function	Provides a broad spectrum of amino acids, including glycine, for overall connective tissue support and repair.	Delivers a concentrated dose of a single amino acid for specific benefits like sleep and neurotransmitter support.
Amino Acid Profile	Contains a blend of amino acids like glycine, proline, and hydroxyproline.	Contains only the amino acid glycine.
Absorption	Often hydrolyzed into smaller peptides for easy absorption.	Absorbed rapidly as a free amino acid.
Best For	General anti-aging, joint support, skin elasticity, and overall connective tissue repair.	Targeting specific goals like improving sleep quality, supporting detoxification, or acting as a calming neurotransmitter.
Synergy	The foundational protein that needs glycine as a key building block.	A concentrated boost that can enhance the effects of collagen, especially during high physical stress or for specific health issues.

Which Types of Collagen Contain Glycine?

All types of collagen contain glycine as a fundamental part of their structure. The specific types found in supplements and their respective sources include:

Type I: The most abundant type, found in skin, bones, tendons, and ligaments. Sourced from bovine and marine collagen.
Type II: Primarily found in cartilage. Sourced mainly from chicken collagen.
Type III: Found alongside Type I in skin, muscles, and blood vessels. Often sourced from bovine collagen.

The high percentage of glycine (approx. 30%) remains consistent across these types, reinforcing that any collagen supplement you choose will be a natural source of glycine.

The Importance of Hydrolyzed Collagen

Most modern collagen supplements are 'hydrolyzed,' meaning the protein has been broken down into smaller, more easily absorbed peptides. This process is crucial because the large collagen molecule is difficult for the body to digest and utilize whole. By breaking it down, the amino acids and peptides become more bioavailable, allowing the body to use them more efficiently for tissue building and other functions. This includes making the high glycine content readily available for collagen synthesis and other metabolic pathways.

Conclusion

In conclusion, the question, 'is there glycine in collagen supplements?' is answered with an unequivocal 'yes.' As the primary and most abundant amino acid in collagen, glycine is inherently present in any quality collagen supplement. Its presence is not a bonus feature but a fundamental component that gives collagen its unique triple-helix structure. By consuming a collagen supplement, you are directly providing your body with a substantial dose of glycine, which supports not only your connective tissues but also a range of other critical bodily functions, from sleep to antioxidant production.

For most individuals, a collagen supplement provides ample glycine to support overall health. However, those with specific needs, such as a strong focus on improving sleep, might consider a targeted glycine supplement in consultation with a healthcare provider. The synergy between collagen and its star amino acid, glycine, offers a robust and effective way to nourish the body from the inside out.

Learn more about collagen's structure and the role of amino acids from the National Library of Medicine: Biochemistry, Collagen Synthesis.

Frequently Asked Questions

Glycine is a natural and fundamental building block of the collagen protein structure. It is not an added ingredient but an inherent component, which is why all authentic collagen supplements naturally contain a significant amount of glycine.

Collagen is composed of about 33% glycine, so a typical serving of a collagen supplement will contain a substantial dose. The exact amount depends on the serving size and the type of collagen used.

All types of collagen (Type I, II, III, etc.) are fundamentally rich in glycine due to its critical role in the triple-helix structure. The high percentage of glycine remains a consistent feature across all types.

For most people, a collagen supplement provides enough glycine for general health. A separate glycine supplement is generally unnecessary unless you are targeting a specific benefit like improved sleep quality or increased detoxification, as extra glycine can have synergistic effects.

Yes, hydrolyzed collagen is broken down into smaller peptides that are more easily absorbed by the body. This makes the high glycine content, along with other amino acids, more readily available for the body's use.

While the body can synthesize some glycine, research suggests that dietary intake often falls short of the amount needed for optimal collagen production, especially as we age. Foods rich in glycine include bone broth, chicken skin, and connective tissue cuts of meat.

Beyond supporting the structural integrity of collagen, the glycine in supplements aids in building strong skin, bones, and joints. It also supports important functions like antioxidant production and improves sleep quality.