Glycine is an amino acid, or a building block for protein. A typical diet that includes protein-rich foods like meat, fish, legumes, and dairy consists of about 2 grams of glycine, however, there are many benefits of glycine when taken in supplement form, including a significant increase in mental performance.
Researchers are continuing to look into the many health benefits of glycine as a dietary supplement. So far, research has alluded to the role of glycine in improving sleep, enhancing memory, and contributing to the treatment of mental disorders like schizophrenia.
There’s also potential for glycine to reduce brain damage after a stroke, heal leg ulcers, and improve insulin sensitivity in diabetics or prediabetics. In this guide, we’ll take a look at the best glycine supplement options today.
How Do Glycine Supplements Work?
Glycine is a neurotransmitter that can be both excitatory and inhibitory, which means it can stimulate activity in the brain and nervous system, or it can reduce it.
Glycine plays an important role in the body, affecting a person’s overall health by influencing his or her cardiovascular, cognitive, and metabolic systems and processes. Glycine, whether in natural or supplement form, is supremely beneficial to the body.
As an amino acid, glycine is a protein builder that promotes the production of collagen. Collagen is an essential part of bones, muscles, tendons, and skin. Collagen is responsible for supplying the body with the structure and strength it needs to function adequately. Glycine also promotes the production of creatine, a vital nutrient that the brain and muscles use for energy.
It also plays an important role in the production of DNA and RNA. Glycine has been found to help in the treatment of schizophrenia, anxiety, depression, obsessive-compulsive disorder (OCD), and addiction. There has also been some research to suggest that higher levels of glycine can alleviate many of the symptoms associated with Parkinson’s disease. <1>
Glycine aids in digestion by allowing the body to more easily break down fatty acids in food and helps to maintain the ideal levels of acidity in the digestive tract. It also works to regulate blood sugar levels and transport blood sugar throughout the body to be used as energy.
Glycine is often used for its anti-inflammatory effects. The amino acid helps regulate the body’s immune response which prevents problem-causing inflammation and promotes healing.
How Does Glycine Improve Mental Performance?
In terms of brain health, glycine functions as a neurotransmitter that affects cognition, mood, pain perception, sleep, and more. The best glycine supplements also help the body produce more serotonin, which influences mood and sleep.
Glycine Can Improve Memory
Glycine can also be beneficial for learning and memory. The neurotransmitter influences key receptors in the brain that affect those important functions.
Research suggests that glycine as a daily supplement can have beneficial effects on memory and attention in adults. In a study of healthy students and middle-aged men, around the age of 20 and 59, Bioglycin (a biologically active form of glycine) greatly improved memory in both age groups. It also promoted sustained attention in the group of middle-aged men.
Researchers in this study noted that Bioglycin was different from other cognitive enhancers in that it didn’t rely on stimulant components and didn’t have a significant effect on mood. Glycine was found to be most beneficial for young adults and older people who struggle with retaining information or who often experience performance issues as the result of jet lag or disrupted sleep. <2>
Taking a Glycine Supplement to Reduce Stress
Reducing stress in the body is another way that glycine improves mental performance.
Glycine is one of the many amino acids needed to produce the antioxidant glutathione in the body. Glutathione is produced by cells to fight free radicals that would otherwise damage cells, proteins, and DNA with oxidative stress. Taking a glycine supplement can help compensate for the lower amount of glutathione produced by the body as it ages.
Glycine can also be used for relief from acute panic attacks. In this case, the suggested use is 2 grams of pure glycine powder placed under the tongue at the onset of an acute panic attack followed by another 2 grams every few minutes until your symptoms subside.
If you suffer from acute panic attacks, talk to your health care provider about whether glycine could be an effective solution for you.
Glycine Promotes Better Sleep
Adequate sleep is essential for optimal mental performance. Not getting enough sleep or a lack of quality, restful sleep can negatively impact just about every system in the body, especially the brain.
Research has shown that higher levels of glycine can help you fall asleep more quickly, reduce symptoms of insomnia, and promote higher quality and more restful sleep. <3>
Researchers have also found that 3g of glycine taken before bedtime significantly improves a person’s quality of sleep while also reducing daytime fatigue. Volunteers who ingested 3g of glycine per day before bed experienced a noticeable improvement in “fatigue”, “liveliness and peppiness”, and “clear-headedness.” <4>
Glycine Contributing to The Treatment of Schizophrenia
Another area in which glycine shows promise as a brain-enhancing supplement is in the treatment of schizophrenia.
In one particular study, patients with schizophrenia were given high doses of glycine as part of their treatment plan. Glycine was added to patients’ ongoing antipsychotic medication as part of a 6-week, double-blind, placebo-controlled crossover treatment trial. Clinical assessments were conducted biweekly throughout the study.
At the end of the study, researchers found that glycine treatment was well-tolerated and resulted in “a significant (P<.001) 30%+/-16% reduction in negative symptoms.”
This clinical trial, as well as similar research being conducted around the world, continues to suggest that glycine may be beneficial as part of the treatment for schizophrenia. At the very least, the research is promising enough to make glycine worth considering for patients with treatment-resistant schizophrenia. <5> <6>
NOW Supplements is a family-owned and operated company based in the United States that has been providing natural health products to people since 1968. The NOW manufacturing process is routinely examined to ensure all laboratory and testing processes meet strict safety and quality standards. NOW maintains an NPA A-rated GMP certification.
The 1,000 mg glycine supplements produced by NOW are designed to promote better and more restful sleep. Glycine works as a calming brain neurotransmitter to improve sleep and provide support for the nervous system.
Glycine capsules from NOW are vegan, pharmaceutical grade, and free-form. Each capsule contains 1,000 mg of glycine. Suggested usage is 1-3 capsules daily, preferably on an empty stomach. This supplement is corn-free, dairy-free, gluten-free, egg-free, nut-free, soy-free, non-GMO, and vegan/vegetarian.
- Glycine — 1,000 mg
- Cellulose (capsule)
- Cellulose powder
- Magnesium stearate (vegetable source)
Life Extension is a company that’s been researching and producing health products and nutritional science for over 40 years. Its glycine supplement provides the body with a semi-essential amino acid that has a calming effect on the brain.
Glycine is produced naturally by the body, but taking a glycine supplement is shown to promote relaxation and more restful sleep. Glycine has also been shown to have a positive effect on cognition, mood, and mental health. It can also help maintain muscle mass and encourage healthy body composition.
Glycine from Life Extension is certified non-GMO and gluten-free. It’s produced in the United States and every product comes with a Certificate of Analysis.
- Glycine — 1,000 mg
- Vegetable cellulose (capsule)
- Ascorbyl palmitate
Glycine by Double Wood Supplements is a supplement that supports healthy sleep quality and as well as liver and kidney health. Glycine is considered a conditionally essential amino acid because the human body can’t synthesize enough glycine on its own.
Double Wood Supplements is a Climate Pledge Friendly company. They’re certified by Amazon for Compact by Design, which means their products remove excess air and water, which lowers the carbon footprint of shipping and packaging.
Research has suggested that three grams of glycine before bed can help you get a better, more restful night of sleep. Glycine is also beneficial for reducing fatigue the next day, so you don’t have to struggle with daytime sleepiness.
Double Wood’s glycine capsules are made in the United States and are gluten-free and non-GMO. Each bottle of glycine contains 300 capsules or 150 servings of 1,000 mg glycine powder.
- L-Glycine 1,000 mg
- Silicon dioxide
- Magnesium stearate
This glycine supplement from Horbaach is non-GMO, gluten-free, and free of wheat, yeast, milk, lactose, soy, artificial color, and artificial flavor. Each quick-release glycine capsule is packed in Horbaach’s FDA-registered facility in the United States.
It should be noted that the Horbaach Glycine label can be misleading. With “3000 mg” on the label, some customers were disappointed to learn that each capsule only contains 1,000 mg. However, as printed on the label, this supplement contains 3,000 mg of glycine per serving of 3 capsules. Each bottle contains a 30-day supply of glycine.
- Glycine (free-form) — 1,000 mg
- Gelatin (capsule)
- Vegetable magnesium stearate
- Rice powder
Thorne Research is a trusted brand that uses the highest-quality ingredients to create exceptional products. Those products then undergo four rounds of testing, ensuring the quality of their products. Thorne is the partner of 11 USA Teams and pro athletes and collaborates with numerous researchers, manufacturers, and organizations including Mayo Clinic and Indena.
These glycine supplements from Thorne Research are formulated to promote relaxation for improved stress management and to modulate cytokine levels in the body that are associated with obesity. In addition to stress management and weight control, glycine is necessary for detoxification. It’s an amino acid that has beneficial effects on the central nervous system.
Each capsule of glycine from Thorne Research contains 1g (1,000 mg) of glycine. The recommended serving size is two capsules. Glycine from Thorne Research is dairy-free, gluten-free, soy-free, egg-free, nut-free, and free of artificial flavors.
- Glycine — 1,000 mg
- Hypromellose (derived from cellulose) capsule
- Silicon dioxide
The final best glycine supplement on our list, Pure Encapsulations has been researching and creating premium supplements for 30 years. Their glycine supplement provides support for detoxification, liver and kidney health, and cognitive health. Glycine has the potential to increase mental performance by supporting memory and brain function.
Each capsule contains 500 mg of glycine. The recommended serving of Pure Encapsulations Glycine is 3 capsules for a total of 1,500 mg. Glycine from Pure Encapsulations is free from wheat, eggs, tree nuts and peanuts, gluten, artificial flavors, artificial colors, artificial sweeteners, coatings and shellacs, GMOs, and unnecessary fillers, binders, and preservatives.
- Glycine — 500 mg
- Vegetarian capsule (cellulose, water)
- Hypoallergenic plant fiber (cellulose)
- Ascorbyl palmitate
- Meerza Abdul Razak, Pathan Shajahan Begum, Buddolla Viswanath, Senthilkumar Rajagopal, “Multifarious Beneficial Effect of Nonessential Amino Acid, Glycine: A Review”, Oxidative Medicine and Cellular Longevity, vol. 2017, Article ID 1716701, 8 pages, 2017. https://doi.org/10.1155/2017/1716701
- File, Sandra E. BSc, PhD, DSc; Fluck, Emma BSc, PhD; Fernandes, Cathy BSc, PhD Beneficial Effects of Glycine (Bioglycin) on Memory and Attention in Young and Middle-Aged Adults, Journal of Clinical Psychopharmacology: December 1999 – Volume 19 – Issue 6 – p 506-512
- Kawai N, Sakai N, Okuro M, et al. The sleep-promoting and hypothermic effects of glycine are mediated by NMDA receptors in the suprachiasmatic nucleus. Neuropsychopharmacology. 2015;40(6):1405-1416. doi:10.1038/npp.2014.326
- Inagawa, K., Hiraoka, T., Kohda, T. et al. Subjective effects of glycine ingestion before bedtime on sleep quality. Sleep Biol. Rhythms 4, 75–77 (2006). https://doi.org/10.1111/j.1479-8425.2006.00193.x
- Waziri, R. (1988). Glycine therapy of schizophrenia. Biological Psychiatry, 23(2), 210–211. https://doi.org/10.1016/0006-3223(88)90093-5
- Heresco-Levy, U et al. “Efficacy of high-dose glycine in the treatment of enduring negative symptoms of schizophrenia.” Archives of general psychiatry vol. 56,1 (1999): 29-36. doi:10.1001/archpsyc.56.1.29