About the Product
Life Pro Nutrition Glycine is a single-ingredient food supplement in powder form: 100% pharmaceutical-grade glycine, with no additives, no sweeteners, no artificial flavours, no colourings and no preservatives. Glycine is the simplest non-essential amino acid in the alpha-amino acid family (with only one hydrogen atom as a side group, making it the only amino acid without chirality), and paradoxically one of the most multifunctional: it participates in collagen synthesis, endogenous creatine production, haemoglobin formation, hepatic conjugation of toxic substances (phase II detoxification), and acts as an inhibitory neurotransmitter in the central nervous system with documented effects on sleep quality and emotional balance. The powder format allows for precise dosage and immediate dissolution in any liquid. Reference dose: 1.5 g per serving (1500 mg of glycine). 300 g per pack (~200 servings of 1.5 g). Gluten-free, lactose-free. Vegan.
Benefits
Glycine: the "non-essential" amino acid that is conditionally essential in contexts of high physiological demand:
Glycine (2-aminoacetic acid, molecular formula NH₂-CH₂-COOH) is classified as a "non-essential" amino acid because the human body can synthesize it endogenously, mainly from serine (via serine hydroxymethyltransferase, SHMT) and threonine. However, recent research questions this classification in contexts of high physiological demand: the endogenous glycine synthesis capacity (estimated at ~3 g/day) may be insufficient to cover the body's total needs in situations of accelerated growth, intense training, high metabolic stress, increased collagen synthesis or compromised liver function. Estimates published in PLoS ONE by Razak et al. (2017) and Alves et al. (2019) suggest that the "glycine gap" (glycine deficit between endogenous synthesis and total metabolic needs) can be 10 to 13 g/day in healthy adults with a typical Western diet, which places glycine in a limbo between "non-essential" and "conditionally essential" based on current evidence.
Collagen synthesis: the central and most documented role of glycine:
Glycine is the most abundant amino acid in collagen (it accounts for ~33% of the total amino acids in collagen), given that the triple-helix structure of collagen requires the repetitive sequence Gly-X-Y (where X is often proline and Y is often hydroxyproline), and only glycine, being the smallest amino acid, fits into the centre of the triple helix without creating steric hindrance. Collagen is the most abundant protein in the human body (~30% of total protein mass), being the main structural component of tendons, ligaments, cartilage, bones, skin, blood vessels and fascia. Collagen synthesis therefore depends on an adequate intake of glycine, and supplementation with glycine together with vitamin C (cofactor of prolyl hydroxylase and lysyl hydroxylase, the enzymes that stabilize the collagen triple helix by hydroxylation of proline and lysine) has a growing evidence base for supporting joint health, recovery from tendon and ligament injuries, and skin health. The study by Shaw et al. (2017) documented that co-ingestion of gelatin (rich in glycine and proline) with vitamin C before joint-loading exercise increased collagen synthesis in a dose-dependent manner.
Inhibitory neurotransmitter and sleep quality: the most studied effect in the context of supplementation:
Glycine is an inhibitory neurotransmitter of the central nervous system, acting mainly on the inhibitory interneurons of the spinal cord and brainstem (via ionotropic glycine receptors, GlyRs), where it hyperpolarizes motor and sensory neurons, reducing neuronal excitability. In addition to GlyRs, glycine is also an obligatory co-agonist of NMDA receptors (N-methyl-D-aspartate) for glutamate, modulating excitatory glutamatergic neurotransmission. In the context of sleep, glycine has a specific mechanism of action documented by studies by Makoto Bannai's group (Japan): oral glycine supplementation (3 g before bed) reduces core body temperature through peripheral vasodilation (via activation of glycine receptors in the hypothalamus that inhibit cutaneous vasoconstriction mechanisms), and the decrease in core body temperature is one of the essential physiological triggers for sleep induction. The clinical trial by Bannai & Kawai (2012), published in Sleep and Biological Rhythms, documented that 3 g of glycine before bed reduced sleep latency (time to fall asleep), increased the proportion of slow-wave sleep (deep sleep), reduced daytime sleepiness, and improved subjective perception of sleep quality in volunteers with complaints of insufficient sleep quality.
Endogenous creatine production: glycine as a precursor of the most documented sports supplement:
Creatine is synthesized endogenously in a two-step pathway: (1) arginine + glycine → guanidinoacetate + ornithine (catalyzed by the AGAT enzyme, in the kidney), (2) guanidinoacetate + methionine → creatine + homocysteine (catalyzed by GAMT, in the liver). Glycine is therefore a direct and limiting precursor of endogenous creatine synthesis. In contexts of high creatine demand (strength and power athletes with large muscle phosphocreatine reserves), additional glycine intake via supplementation can support endogenous creatine synthesis, being complementary (not a substitute) to direct creatine monohydrate supplementation.
Phase II hepatic detoxification: conjugation of glycine with bile acids and xenobiotics:
In the liver, glycine actively participates in phase II detoxification (the second phase of hepatic xenobiotic metabolism, where activated phase I metabolites are conjugated with endogenous molecules to increase their solubility and facilitate excretion). Glycine is specifically used in the conjugation of bile acids (forming glyco-conjugated bile salts, such as glycocholate and glycochenodeoxycholate, which are more soluble forms of bile acids that facilitate the emulsification of fats in digestion) and in the conjugation of xenobiotics (aromatic compounds such as benzoate, salicylate, and other aromatic ring compounds are eliminated as glyco-conjugates in urine). Adequate glycine availability supports the efficiency of these detoxification processes, especially relevant in individuals with high exposure to xenobiotics or with diets rich in aromatic compounds.
Haemoglobin formation and antioxidant function via glutathione:
Glycine is one of the three amino acid precursors of glutathione (γ-glutamyl-cysteinyl-glycine tripeptide), the body's main intracellular antioxidant. In glutathione synthesis, glycine is the third and last amino acid to be incorporated (by the glutathione synthetase enzyme), and glycine availability can be limiting for glutathione synthesis in situations of high oxidative stress (such as high-intensity training). In addition to glutathione, glycine is also a precursor of porphyrins (via succinyl-CoA + glycine → delta-aminolevulinate, the first step in porphyrin synthesis), which are the tetrapyrrole rings that make up the heme group of haemoglobin and myoglobin.
100% pure powder format: versatility, precise dosage and ease of combination:
The single-ingredient powder format of Life Pro Glycine has significant practical advantages compared to capsule versions available on the market: it allows for completely adjustable dosage (from 1 g to 5 g depending on the goal and individual tolerance); it dissolves easily in water, juices, smoothies or other liquids without residual taste (glycine has a natural slightly sweet taste); it can be added to protein shakes (combining with the post-workout muscle recovery effect), to pre-sleep drinks (taking advantage of the sleep quality improvement effect) or incorporated into recipes; and it can be easily combined with other supplements such as creatine, collagen or vitamin C without interactions or incompatibilities.
Uses
Recommended dose and timing: For improved sleep quality: 3 g (2 scoops of 1.5 g) dissolved in warm water 30 to 60 minutes before bed, without food (for maximum absorption and rapid effect on hypothalamic receptors). For collagen synthesis and joint health: 3 to 5 g with vitamin C 30 to 60 minutes before exercise involving joint loading. For muscle recovery and protein synthesis: 1.5 to 3 g dissolved in post-workout shake. Can be used daily without the need for cycles or breaks.
