Glycine Capsules

Glycine – Sleep & Nervous System Support

Supports deeper sleep, relaxation, and nervous system recovery.

Choose Your Format

• Capsules – convenient, precise dosing, easy to take on the go
• Powder – flexible dosing, ideal before bed in water

Most people start with capsules for simplicity.

What is Glycine

Glycine is the smallest and simplest of the amino acids, and one of the most abundant in the human body. It is a conditionally essential amino acid — meaning the body produces it, but dietary intake is often insufficient to meet the body’s full requirements. Glycine plays a foundational role in numerous biological processes and is a popular supplement in functional nutrition and integrative health practice.

Glycine is involved in the production of:

• Glutathione — the body’s primary antioxidant
• Collagen — the most abundant protein in the body
• Creatine — for cellular energy
• Bile salts — for fat digestion
• Haemoglobin — for oxygen transport
• DNA and RNA bases

It also functions as an inhibitory neurotransmitter in the central nervous system, playing a role in neural signalling and the regulation of excitatory activity in the brain and spinal cord.

The Methionine & Glycine Balance

This is one of the most overlooked aspects of modern nutrition — and one of the most important.

Methionine and glycine have an inverse relationship in the body. As methionine intake increases, the body’s need for glycine rises proportionally — roughly 0.5 to 1 gram of glycine for every gram of methionine consumed.

The problem? The modern Western diet is high in methionine-rich foods — meat, fish, eggs, and dairy — while being very low in the glycine-rich foods our ancestors ate regularly: bone broth, gelatin, and connective tissue. The result is a widespread, silent glycine deficit that most people never connect to their symptoms.

Signs of this imbalance can include:

• Poor sleep and difficulty winding down
• Inflammation and joint discomfort
• Sluggish detoxification
• Skin and connective tissue issues
• Low energy and poor recovery

Supplementing with glycine is a simple, well-tolerated way to restore this balance — particularly for those eating a high-protein diet. It’s not about eating less protein. It’s about making sure your glycine keeps pace.

What the Experts Say

Ray Peat, PhD

“Glycine protects against fibrosis, inflammation, free radical damage, and mitochondrial dysfunction.”

Dr. Ray Peat wrote extensively about glycine as one of the most important and underappreciated amino acids, particularly in the context of balancing methionine intake and supporting mitochondrial function.

Paul Saladino, MD

Dr. Paul Saladino highlights the dietary imbalance created by eating muscle meat without the connective tissue that traditionally accompanied it. He argues that rather than restricting methionine — as some plant-based advocates suggest — the smarter approach is to ensure adequate glycine intake.

“Glycine supplementation extends lifespan of male and female mice.”

He notes that for those eating a muscle-meat-heavy diet without connective tissue cuts or bone broth, glycine supplementation is a practical and effective solution. Restricting methionine, by contrast, leads to malnourishment — not longevity.

These perspectives are presented for informational context.

Traditional & Nutritional Use

Sleep & Nervous System

Glycine is widely used in nutritional practice to support sleep quality and nervous system calm. As an inhibitory neurotransmitter, it plays a role in supporting the parasympathetic (rest-and-recover) state. Capsules are ideal for precise dosing before bed.

Recovery & Cellular Protection

Glycine is a precursor to glutathione — the body’s primary endogenous antioxidant. It is also essential for collagen synthesis, making it relevant for connective tissue, skin, and joint support.

Liver & Metabolic Support

Glycine is involved in bile acid conjugation and liver detoxification pathways. It is commonly used in nutritional practice to support liver function and healthy metabolic processes.

Key Benefits

• Supports relaxation and nervous system calm
• Helps improve sleep quality
• Helps reduce stress and mental fatigue
• Supports recovery and cellular protection

How Glycine Works

Glycine supports the body through several key mechanisms:

• Acts as an inhibitory neurotransmitter to calm the brain
• Reduces neural over-activity and mental tension
• Supports parasympathetic (rest-and-recover) function
• Helps regulate nighttime cortisol patterns

Who It’s For

Glycine may be beneficial if you experience:

• Difficulty falling asleep
• Light or disrupted sleep
• Mental over-activity at night
• Ongoing stress or fatigue
• Poor recovery

It is also particularly relevant for anyone eating a high-protein diet who wants to ensure their methionine and glycine remain in balance.

Dosage Guide

Take as directed by your healthcare practitioner. For adults only.

Stack This With

• Glycine Powder — same formula in powder format for flexible dosing
• Magnesium Glycinate — nervous system and recovery support
• Oat Straw Extract — traditional nervine support
• Gumpii Extract — foundational botanical base

Related Wellness Guides

• Natural Sleep Support
• Glycine — What Is It & Why It Matters
• Wellness Hub — explore all herbal guides

Research Insight

Content provided for informational purposes only. Not medical advice. Not intended to diagnose, treat, or cure any condition. Consult your healthcare practitioner.