Do I need to take glycine if I take collagen?

November 28, 2025 •

4 min read

Research suggests that although the body can produce its own glycine, the amount may not be enough to meet the high metabolic demands, especially as we age. This raises the question: do I need to take glycine if I take collagen to maximize health benefits?

Quick Summary

Taking a collagen supplement provides a rich source of glycine, but additional glycine may still be beneficial depending on individual needs. The body's demand for glycine can exceed its production, making supplementation worthwhile for targeted benefits like improved sleep, enhanced detoxification, or accelerated tissue repair.

Key Points

Collagen contains glycine: All collagen supplements are naturally high in glycine, a critical building block for the collagen protein itself.
Insufficient glycine production: Your body’s natural production of glycine may not be enough to meet all its needs, especially with age or stress.
Synergistic benefits: Taking extra glycine with collagen can amplify overall health benefits, particularly for sleep quality, joint health, and tissue repair.
Targeted vs. broad support: Collagen provides broad structural support, while supplemental glycine offers targeted benefits for metabolic, cognitive, and detoxification pathways.
Consider your goals: For enhanced sleep or liver function, an extra glycine supplement is beneficial; for general maintenance, a high-quality collagen supplement may suffice.
Timing can matter: Taking collagen in the morning and glycine in the evening can be an effective strategy to leverage each supplement's unique benefits.

Understanding the Relationship Between Glycine and Collagen

Collagen and glycine are fundamentally linked, as glycine is the most abundant amino acid within the collagen protein itself, constituting approximately 20-33% of its structure. Collagen is the body's most prevalent protein, providing structural integrity to skin, bones, tendons, and cartilage. When you take a collagen supplement, you are inherently consuming glycine, along with other key amino acids like proline and hydroxyproline.

Why Your Body Needs More Glycine

Despite glycine being classified as a 'non-essential' amino acid because the body can produce it, the synthesis is often insufficient to meet metabolic demands, especially as you age or face stressors like illness and intense exercise. This deficit, estimated by some research to be around 10 grams per day for the average adult, can impact various bodily functions beyond just collagen synthesis. By taking collagen, you provide raw material for collagen production, but supplementing with extra glycine can offer targeted benefits that go beyond the structural support provided by collagen alone.

Benefits of Supplementing Both Collagen and Glycine

Combining collagen and a separate glycine supplement can create a synergistic effect, amplifying the benefits for various bodily systems.

Skin Health:

Collagen: Provides the foundational matrix for skin, improving its firmness, hydration, and elasticity to reduce the appearance of wrinkles.
Glycine: Supports wound healing, tissue repair, and moisture retention. It also possesses anti-inflammatory properties that can protect against collagen degradation.

Joint and Bone Health:

Collagen: Is a critical component of cartilage and bone, helping to improve joint mobility and alleviate discomfort.
Glycine: Directly enhances the synthesis of collagen, particularly type II collagen found in cartilage, which is vital for tissue regeneration. Research suggests a deficiency in glycine can lead to impaired collagen synthesis and contribute to conditions like osteoarthritis.

Sleep and Mental Well-being:

Glycine: Is a calming neurotransmitter that promotes better sleep quality by lowering core body temperature and reducing the time it takes to fall asleep. This is a unique benefit that collagen, on its own, does not provide.
Collagen: Promotes overall rest and recovery by supporting the body's repair processes during sleep, but does not have the same direct neurological effect as free-form glycine.

Gut Health:

Collagen: Helps strengthen and repair the gut lining, which can reduce intestinal permeability.
Glycine: Possesses anti-inflammatory properties that soothe irritated gut tissue and support overall digestive function.

Comparison Table: Collagen vs. Additional Glycine


Feature	Collagen Supplement	Additional Glycine Supplement
Primary Role	Provides a complete amino acid profile to rebuild and strengthen connective tissue.	Supplies extra glycine for targeted metabolic and neurological functions.
Glycine Content	Contains approximately 20-33% glycine by weight, alongside other amino acids.	Typically provides a higher, concentrated dose of free-form glycine per serving.
Main Benefits	Comprehensive support for skin, hair, nails, and joints due to its full protein matrix.	Targeted benefits for sleep quality, anti-inflammatory effects, and liver detoxification.
Mechanism	The body breaks down hydrolyzed collagen peptides into amino acids and uses them to fuel its own collagen production.	The free-form glycine is quickly absorbed and used for functions beyond structural repair.

How to Approach Supplementation

For most people, a high-quality collagen supplement already provides a significant amount of glycine, which may be sufficient for general needs. However, if you are seeking specific, amplified benefits—such as improved sleep, enhanced liver function, or extra support for connective tissue repair—adding a separate glycine supplement is a well-supported strategy.

To integrate these, you can take your regular collagen supplement in the morning and a glycine supplement in the evening to leverage its sleep-promoting effects. It is also recommended to combine them with Vitamin C, as this nutrient is essential for the body to synthesize and utilize collagen effectively.

Before adding any new supplement to your routine, it's wise to consult with a healthcare professional, especially if you have pre-existing health conditions. They can help you determine the appropriate dosage and timing for your specific needs.

Conclusion

While a collagen supplement is rich in glycine, a separate glycine supplement can be a valuable addition for those with higher metabolic demands or specific health goals like improved sleep or targeted anti-inflammatory effects. The two supplements are not mutually exclusive but rather synergistic, with collagen providing the broad structural building blocks and supplemental glycine offering focused support for various physiological processes. By understanding their distinct roles, you can make an informed decision on whether to add a separate glycine supplement to your regimen to maximize your wellness journey.

Additional Resources

For further reading on the critical role of glycine in collagen synthesis, a detailed study is available on the National Institutes of Health website. PMC6153947

Frequently Asked Questions

Collagen is one of the richest sources of glycine, with the amino acid making up roughly 20-33% of its composition. For general health, this amount can be significant, but the body's overall demand for glycine often exceeds its internal production, especially with age. Therefore, for targeted benefits like better sleep or enhanced detoxification, additional glycine supplementation may be necessary.

Taking glycine and collagen together can amplify benefits for skin, joints, and overall wellness. Collagen provides the broad structural protein matrix, while extra glycine enhances specific functions like sleep quality, anti-inflammatory support, and liver detoxification. This creates a synergistic effect that goes beyond the benefits of taking either supplement alone.

Yes, it is often beneficial to take glycine separately for sleep even if you take collagen. Glycine's calming neurological effects, which help promote sleep, are most effective when taken in a concentrated, free-form dose before bed. The glycine within your morning collagen supplement primarily supports protein synthesis and structural repair.

Glycine is generally well-tolerated, and adverse effects from high doses are rare. However, excessive intake from supplements might cause mild stomach discomfort in some individuals. It is always best to follow the recommended dosage and consult a healthcare provider before beginning any new supplement regimen.

Neither is definitively 'better'; they serve different purposes. Pure glycine is ideal for targeting specific benefits like sleep and mood. Collagen, which contains glycine and 17 other amino acids, offers a broader range of benefits for overall connective tissue health. Your choice depends on whether you seek broad nutritional support or a more targeted effect.

Both are crucial for joint health. While collagen provides the raw materials to rebuild cartilage and connective tissue, glycine specifically enhances the synthesis of collagen, particularly Type II, which is vital for cartilage regeneration. Research has shown that high glycine concentrations promote more robust collagen synthesis in cartilage cells.

For many, the body's natural synthesis of glycine is insufficient to meet high metabolic demands, especially with increasing age or physical stress. This can result in a daily deficit of several grams, potentially impacting optimal collagen production and other bodily functions.