Description

Glycine is an amino acid with no L or D chemical configuration. It is synthesized from choline, serine, hydroxyproline, and threonine. The extracellular structural proteins such as elastin and collagen are made up of glycine. Consumption of glycine in very low quantities may lead to the failure of immune response & growth, abnormal nutrient metabolism, and undesirable effects on health. Therefore, glycine is considered as a conditionally essential amino acid (1). 

Role of glycine in collagen synthesis 

Glycine, proline, and lysine play a vital role in collagen structure and their insufficient availability could make collagen synthesis and regeneration difficult (2). Glycine is used for protein synthesis. In a collagen molecule, glycine is located at every third position; glycine brings together the triple helix of the collagen. Glycine provides flexibility for enzyme active sites (1). 

Glycine plays a crucial role as a neurotransmitter in the central nervous system, thus it regulates the intake of food, behavior, and complete body homeostasis (1).

Glycine regulates immune function. It alters the intracellular Ca2+ levels & helps in the production of superoxide, and the synthesis of cytokines. Glycine indirectly participates in the absorption and digestion of lipids & lipid-soluble vitamins. The conjugation of bile acids in humans is facilitated by glycine (1).  

RNA, DNA, creatine, & serine are synthesized by several glycine utilizing pathways. Glycine is a precursor of important metabolites such as glutathione, porphyrins, purines, and creatine. Therefore, glycine plays a crucial role in cytoprotection, immune response, growth, development, & metabolism (1). 

Glycine and sleep management 

Glycine subjectively and objectively improves sleep quality in humans who have difficulty sleeping.

• A glycine-induced increase in the neuropeptides arginine vasopressin and vasoactive intestinal polypeptide in the light period (3).
• Results indicate that glycine modulated the suprachiasmatic nucleus (SCN) function. Thus, glycine modulates certain neuropeptides in the SCN and this phenomenon may indirectly contribute to improving the occasional sleepiness and fatigue induced by sleep restriction (3).
• In both the peripheral and central nervous systems, glycine acts as an inhibitory neurotransmitter via glycine receptors (3)
• Glycine improved subjective parameters, such as fatigue initially and objective parameters, such as psychomotor vigilance were improved as well (3).
• Glycine improved subjective sleep quality and sleep efficacy (sleep time/in-bed time), and shortened polysomnography (PSG) latency both to sleep onset and to slow wave sleep without changes in the sleep architecture (4).
• Glycine lessened daytime sleepiness and improved performance of memory recognition tasks. Thus, a bolus ingestion of glycine before bedtime seems to produce subjective and objective improvement of the sleep quality in a different way than traditional hypnotic drugs (4). 

The Unived difference

It is vegan. It is free of known allergens and artificial additives.

Evidence-Based or Bust

We use ingredients backed by a significant body of research that is growing each day.

1. Multifarious Beneficial Effect of Nonessential Amino Acid, Glycine: A Review.
   Razak MA, Begum PS, Viswanath B, Rajagopal S. Multifarious Beneficial Effect of Nonessential Amino Acid, Glycine: A Review. Oxid Med Cell Longev. 2017;2017:1716701.
2. High glycine concentration increases collagen synthesis by articular chondrocytes in vitro: acute glycine deficiency could be an important cause of osteoarthritis
   Patricia de Paz Lugo et. al.,“High glycine concentration increases collagen synthesis by articular chondrocytes in vitro: acute glycine deficiency could be an important cause of osteoarthritis” Springer Amino Acids (2018) 50:1357–1365
3. The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers.
   Bannai, M., Kawai, N., Ono, K., Nakahara, K., & Murakami, N. (2012). The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers. Frontiers in neurology, 3, 61.
4. Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes.
   Yamadera, W., Inagawa, K., Chiba, S., Bannai, M., Takahashi, M., & Nakayama, K. (2007). Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes. Sleep and Biological Rhythms, 5, 126-131. https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1479-8425.2007.00262.x?crsi=662497714&cicada_org_src=healthwebmagazine.com&cicada_org_mdm=direct