Nutrition Diet: Does Glycine Lower Inflammation?

October 7, 2025 •

3 min read

Recent studies have identified glycine's remarkable potential to reduce inflammation in the body. As the smallest non-essential amino acid, glycine plays a vital role beyond protein synthesis, exerting powerful anti-inflammatory effects by modulating immune cell function and suppressing pro-inflammatory molecules. This exploration reveals the science behind the question: Does glycine lower inflammation?

Quick Summary

Glycine, a fundamental amino acid, is gaining recognition for its ability to reduce chronic inflammation. It works by regulating cytokine production, modulating immune cell responses through specific receptors, and acting as a precursor to the potent antioxidant glutathione. Evidence from both animal and human studies suggests that optimizing glycine intake can help control inflammatory processes and support overall cellular health.

Key Points

Glycine Modulates Immune Cells: Glycine acts on receptors in immune cells like macrophages to suppress pro-inflammatory cytokine release.
Boosts Antioxidant Defenses: It is a key precursor to glutathione, the body's master antioxidant, which helps combat inflammation-causing oxidative stress.
Supports Metabolic Health: Glycine can improve insulin sensitivity and regulate inflammatory markers in conditions linked to metabolic dysfunction.
Best Found in Collagen: Dietary sources rich in glycine include bone broth, chicken skin, and gelatin, as well as plant-based options like seeds and legumes.
Varying Clinical Results: While animal studies show strong anti-inflammatory effects, human trials have shown varied outcomes depending on the condition and severity, indicating more research is needed.

The Multifaceted Role of Glycine

Glycine is the simplest amino acid, involved in protein synthesis and the creation of creatine and glutathione. While the body can make glycine, dietary sources may be important, especially during periods of high demand or chronic inflammation.

Mechanisms of Glycine's Anti-Inflammatory Action

Glycine's ability to lower inflammation is complex, involving direct effects on immune cells and broader impacts on oxidative stress and metabolism.

Immune Cell Modulation

Glycine can influence inflammatory cells like macrophages and neutrophils. It activates specific glycine-gated chloride channels, which helps to reduce the release of pro-inflammatory cytokines such as TNF-α and IL-6.

Antioxidant and Detoxification Support

Glycine is essential for the production of glutathione, a key antioxidant in the body. Glutathione helps neutralize harmful free radicals that contribute to inflammation. Supplementing with glycine can increase glutathione levels, improving the body's antioxidant defenses and reducing oxidative stress.

Metabolic Regulation

Chronic inflammation is often linked to metabolic issues like insulin resistance. Glycine has shown potential benefits for metabolic function. Some studies suggest it can improve insulin sensitivity and help regulate inflammatory markers in conditions like obesity.

Comparing Glycine's Anti-Inflammatory Effects to Other Agents

Comparing glycine to other anti-inflammatory agents like N-acetylcysteine (NAC) can highlight its unique benefits. A combination of glycine and NAC (GlyNAC) appears to offer superior effects.


Feature	Glycine	N-acetylcysteine (NAC)	Combination (GlyNAC)	Result
Mechanism	Modulates immune cells and aids glutathione synthesis.	Supports glutathione synthesis and scavenges free radicals.	Combines mechanisms for enhanced glutathione production.	Significant reduction in inflammation and oxidative stress compared to either alone.
Efficacy	Effective for inflammation.	Effective, especially for antioxidant status.	More effective than either alone, particularly in older adults.	The combination shows synergistic effects.
Application	Broad uses for various inflammatory conditions.	Used for respiratory and liver issues.	Addresses age-related decline, oxidative stress, and inflammation.	Supports a comprehensive approach to managing inflammation.

How to Increase Glycine Intake

Glycine levels can be increased through diet and supplements.

Dietary Sources

Foods rich in glycine are primarily those containing collagen.

Animal-Based: Bone broth, meat with skin and cartilage, fish, and gelatin.
Plant-Based: Legumes, seeds (pumpkin, sesame, chia), and certain grains and nuts (quinoa, pistachios).

Supplementation

Glycine supplements are available in powder or capsule form. Study dosages have ranged from 5 to 15 grams daily. Consulting a healthcare professional for appropriate dosage is advised, especially with existing health conditions. Choosing a reputable, third-party-tested brand is recommended for quality.

Research and Clinical Considerations

While promising, more research is needed to fully understand glycine's effects in diverse clinical settings. For instance, a study on severe COVID-19 patients found no significant improvement with enteral glycine. However, earlier research in cystic fibrosis patients showed positive effects on inflammatory markers and lung function. These varying results underscore the need for further investigation across different patient groups and conditions.

Conclusion

Evidence suggests that glycine does lower inflammation by influencing immune cells and boosting antioxidant defenses. Increasing glycine through diet or supplementation may help manage inflammatory conditions. However, individuals with severe illnesses may have different needs, and professional medical advice is always recommended before starting supplementation. For a more in-depth look at glycine's immunomodulatory mechanisms, a detailed review is available.

Frequently Asked Questions

Glycine reduces inflammation primarily by modulating immune cells, such as macrophages, through specific glycine-gated chloride channels. This activation leads to reduced production of pro-inflammatory cytokines like TNF-α and IL-6.

While the body can produce glycine, dietary intake may be insufficient to meet optimal levels, especially with modern diets low in collagen. Dietary sources include bone broth, chicken skin, gelatin, and plant-based foods like seeds and legumes.

Glycine is a crucial building block for glutathione, a powerful antioxidant. By increasing glycine availability, the body can synthesize more glutathione, which neutralizes harmful free radicals and reduces the oxidative stress that drives inflammation.

Glycine is generally well-tolerated, but people should consult a healthcare provider before supplementing. It should be used with caution in individuals taking clozapine or those with certain health conditions. A healthcare provider can recommend an appropriate dose.

Studies show that glycine can help improve insulin sensitivity and regulate inflammatory markers often associated with metabolic disorders like obesity and type 2 diabetes. Low plasma glycine levels are often linked to insulin resistance.

The time it takes to see effects can vary. One study on cystic fibrosis patients observed improvements in inflammatory markers and clinical status after 8 weeks of supplementation, suggesting a relatively slow onset of action.

Common food sources high in glycine include bone broth, chicken skin, ground beef, and gelatin. Plant-based sources include soybeans, pumpkin seeds, and quinoa.