Glycine: Nootropic Benefits, Uses, Dosage, & Side Effects

Glycine, a simple yet powerful amino acid, plays vital roles in the body and brain.

It functions as a neurotransmitter, aids in collagen production, and regulates sleep. Glycine offers cognitive benefits, including improved memory, reduced anxiety, and neuroprotection.

It’s found in foods like bone broth and meat and can be taken as a supplement.

Typically dosed at 3-5 grams daily, glycine is generally safe and well-tolerated, making it a promising option for those seeking cognitive enhancement and better sleep.

What is Glycine?

Glycine is a non-essential proteinogenic amino acid that plays a crucial role in the body and brain.

As one of the simplest amino acids, glycine has a single hydrogen atom as its side chain, giving it the chemical formula C₂H₅NO₂.

Glycine is involved in various physiological processes, including neurotransmission, collagen (a building block of proteins) production, and sleep regulation.

Additionally, it aids in the synthesis of glutathione, a potent antioxidant that combats oxidative stress and supports immune function. Glycine is also a precursor for heme, a vital component of hemoglobin that carries oxygen in red blood cells.

What Are the Sources of Glycine?

Glycine is obtained through endogenous synthesis in the body and from dietary sources.

The body can synthesize glycine from serine, threonine, choline, and hydroxyproline.

Foods high in glycine include:

• Bone broth
• Gelatin
• Meat, fish, and poultry
• Legumes and soy products

Supplementation is another source of the nutrient where specific dosages are required for health benefits.

How Does Glycine Work as a Nootropic?

Glycine has gained attention as a nootropic due to its role in neurotransmission and its potential cognitive benefits. As an inhibitory neurotransmitter, glycine helps regulate neuronal activity, promoting a balanced and healthy brain function.

Glycine has been associated with several cognitive benefits:

1. Improved sleep quality
2. Enhanced memory
3. Reduced anxiety and stress
4. Neuroprotection and Neurogenesis

Does Glycine Enhance Memory?

Glycine has been shown to enhance memory formation and retention. This effect is mediated by glycine’s role in modulating NMDA (N-methyl-D-aspartate) receptors, which are crucial for synaptic plasticity and long-term potentiation (LTP) in the hippocampus, a brain region essential for learning and memory.

A study by Heresco-Levy et al. demonstrated that glycine administration improved verbal memory and learning in healthy volunteers.⁽¹⁾

Glycine’s role in enhancing memory formation and synaptic plasticity enhances learning capabilities. By facilitating LTP in the hippocampus, glycine supports the brain’s ability to form new neural connections and acquire new information.

Does Glycine Affect Sleep Quality?

Glycine has been shown to improve sleep quality and reduce daytime sleepiness. A study by Yamadera et al. found that oral glycine administration before bedtime significantly improved subjective sleep quality, sleep efficiency, and reduced fatigue in individuals with mild sleep complaints.⁽²⁾

The mechanisms behind glycine’s sleep-promoting effects are not fully understood, but it’s thought to involve modulation of neurotransmission and regulation of core body temperature.

Does Glycine Reduce Anxiety and Stress?

Glycine does have stress relieving effects. It works by enhancing the activity of GABA (gamma-aminobutyric acid), another inhibitory neurotransmitter that helps calm neural activity and promote relaxation. This process occurs mainly in the brainstem and spinal cord, where glycine receptors are abundant.

Research has shown glycine’s potential in modulating the body’s response to stress by lowering cortisol levels, a hormone associated with stress.⁽³⁾ These findings suggest that glycine’s calming effects on the nervous system may help reduce anxiety and stress.

Can Glycine Help in Recovery from Brain Injuries?

Glycine may aid in recovery from brain injuries due to its neuroprotective properties.

Glycine helps regulate neural activity and reduce excitotoxicity, a condition where excessive stimulation by neurotransmitters leads to neuron damage.⁽⁴⁾

It binds to NMDA receptors in the brain, which helps maintain calcium homeostasis, thus preventing the harmful effects of excessive calcium influx that can occur after brain injury.⁽⁵⁾

Additionally, glycine enhances the production of antioxidant glutathione, reducing oxidative stress and inflammation. These combined effects support neuronal survival and repair, potentially improving outcomes after brain injuries.

Does Glycine Protect Against Brain Aging and Neurodegenerative Disorders?

Glycine’s neuroprotective effects extend to protecting against neurodegeneration and brain aging.

Its antioxidant and anti-inflammatory properties, along with its role in regulating neuronal excitability, help maintain brain health and prevent age-related cognitive decline.

Studies have shown that glycine supplementation can attenuate age-related changes in the brain, such as oxidative stress and mitochondrial dysfunction.⁽⁵⁾

Another study in Neurotherapeutics showed that glycine administration reduced oxidative stress and inflammation, leading to improved neuronal survival and function in models of Alzheimer’s disease.⁽⁶⁾

How to Use Glycine as a Supplement?

Glycine is available as a dietary supplement in powder and capsule forms. It’s often used as a standalone supplement or in combination with other nootropics or sleep aids.

What Are the Recommended Dosages for Glycine?

The typical dosage range for glycine supplementation is 3-5 grams per day.

It’s important to start with the lowest effective dose and consult a healthcare professional before starting any new supplement regimen.

How Should Glycine Be Taken?

Glycine powder can be mixed with water or other beverages and consumed directly. Capsules should be taken with a glass of water.

For sleep benefits, glycine is best taken 30-60 minutes before bedtime.

Can Glycine Be Combined with Other Nootropics?

Glycine can be combined with other nootropics for potential synergistic effects. Some common nootropic combinations include:

• Glycine + Magnesium: Enhances sleep quality and relaxation
• Glycine + L-Theanine: Promotes calmness and reduce stress
• Glycine + Caffeine: Improves focus and cognitive performance while reducing jitteriness

However, it’s essential to research potential interactions and consult a healthcare professional before combining supplements.

What Are The Side Effects and Safety Considerations of Glycine?

Glycine is generally well-tolerated, with few reported side effects when used at recommended doses.

What Are Glycine’s Potential Side Effects?

Common side effects of glycine supplementation are mild and may include:

• Nausea
• Stomach upset
• Headache
• Dizziness

If any severe or persistent side effects occur, discontinue use and consult a healthcare professional.

Who Should Avoid Glycine Supplements?

Individuals with certain pre-existing conditions should avoid glycine supplements or consult a healthcare professional before use:

• Pregnant or breastfeeding women
• Individuals with kidney or liver disease
• Those taking medications that interact with glycine, such as clozapine

How Does Glycine Compare to Other Nootropics and Cognitive Enhancers?

Glycine is a unique nootropic with a specific set of benefits related to sleep, memory, and stress reduction. Compared to other nootropics, glycine has several advantages and disadvantages.

Advantages of Glycine

1. Well-tolerated: Glycine has a low risk of side effects compared to some other nootropics.
2. Affordable: Glycine supplements are generally inexpensive compared to many other cognitive enhancers.

Disadvantages of Glycine

1. Mild effects: Glycine’s cognitive-enhancing effects may be less pronounced than those of some other nootropics, such as racetams or stimulants.
2. Limited research: While promising, human studies on glycine’s nootropic effects are still limited compared to more extensively researched compounds.
3. Specific benefits: Glycine’s benefits are primarily related to sleep, memory, and stress reduction, whereas some other nootropics may offer a broader range of cognitive enhancements.

Glycine may be an excellent option for those seeking a well-tolerated, affordable supplement with sleep and memory benefits, while others may prefer nootropics with more potent or diverse effects.

1. File, Sandra E., Emma Fluck, and Cathy Fernandes. “Beneficial effects of glycine (bioglycin) on memory and attention in young and middle-aged adults.” Journal of clinical psychopharmacology 19.6 (1999): 506-512.↩
2. Bannai, Makoto, and Nobuhiro Kawai. “New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep.” Journal of pharmacological sciences 118.2 (2012): 145-148.↩
3. Zhang, Cheng Gao, and Sung-Jin Kim. “Taurine induces anti-anxiety by activating strychnine-sensitive glycine receptor in vivo.” Annals of Nutrition and Metabolism 51.4 (2007): 379-386.↩
4. Gusev, E. I., et al. “Neuroprotective effects of glycine for therapy of acute ischaemic stroke.” Cerebrovascular Diseases 10.1 (2000): 49-60.↩
5. Sacco, Ralph L., et al. “Glycine antagonist in neuroprotection for patients with acute stroke: GAIN Americas: a randomized controlled trial.” Jama 285.13 (2001): 1719-1728.↩↩
6. Kanski, Jaroslaw, et al. “Role of glycine-33 and methionine-35 in Alzheimer’s amyloid β-peptide 1–42-associated oxidative stress and neurotoxicity.” Biochimica et Biophysica Acta (BBA)-Molecular Basis of Disease 1586.2 (2002): 190-198.↩