Glycine
An amino acid that modulates NMDA receptors and may reduce sleep latency.
Glycine reduces sleep latency in human RCTs
Glycine (3g before bed) significantly reduces sleep onset latency and improves subjective sleep quality in healthy adults. Evidence from 3 human RCTs shows consistent effects, with the mechanism involving NMDA receptor modulation and thermoregulation.
Glycine improves overall sleep quality and reduces daytime sleepiness
Beyond reducing sleep latency, glycine (3g before bed) improves PSG-measured sleep quality including increased REM sleep and reduced nocturnal awakenings. Daytime sleepiness and fatigue are also significantly reduced the following morning.
A novel nutritional blend of tryptophan, glycine, magnesium, tart cherry powder, and l-theanine reduces sleep onset latency and increases total sleep time and efficiency in healthy adults.
In a randomized, double-blind crossover study with 16 healthy adults, a nutritional blend reduced sleep onset latency by 24 ± 25 minutes (P=0.002), increased total sleep time by 22 ± 32 minutes (P=0.01), and improved sleep efficiency by 2.4% ± 3.9% (P=0.03), while also reducing morning sleepiness (P=0.02). The effects may be mediated by upregulation of key metabolites like 6-sulfatoxymelatonin, D-serine, and L-glutamic acid.
NNZ-2591 improves sleep in children and adolescents with Phelan-McDermid syndrome
In an open-label phase 2 trial, NNZ-2591 was associated with significant improvements in sleep assessments among 18 children and adolescents with Phelan-McDermid syndrome after 13 weeks of treatment. Sleep was one of 14 secondary efficacy endpoints, with significant improvement from baseline observed at week 13.
Dietary and supplementation protocols focused on sleep-promoting nutraceuticals can act as subsidiary sleep aids in complementing behavioral sleep hygiene changes.
This narrative review summarizes evidence that selected nutraceuticals, including melatonin, magnesium, omega-3 fatty acids, tart cherry juice, kiwifruit, apigenin, valerian root, L-theanine, glycine, ashwagandha, myoinositol, Rhodiola rosea, and phosphatidylserine, may improve sleep quality and quantity. The paper suggests these compounds can serve as adjuncts to good sleep hygiene practices for individuals with circadian rhythm and sleep disturbances.
Unclassified pulmonary hypertension most often reflects subclinical left heart and metabolic dysfunction consistent with unrecognized early-stage heart failure with preserved ejection fraction (HFpEF).
In a combined cohort of 2,248 participants, unclassified PH had a prevalence of 7.8%. Among those with unclassified PH, 59% (72/122) showed exertional pulmonary artery wedge pressure elevation consistent with undiagnosed HFpEF during exercise testing. The condition was associated with greater adiposity, higher HFpEF probability scores, left heart remodeling, and lower glycine metabolites indicative of metabolic dysfunction.
Glycine as an indirect structural inducer enhances silk fibroin piezoelectric performance for facial micromotion tracking during sleep
The study developed a fully green bioelectronic piezoelectric patch using silk fibroin with glycine as a structural inducer, which improved β-sheet content and piezoelectric performance. The patch enabled dual-channel wireless monitoring of rapid eye movements and nasal flaring during sleep with high conformability and sensitivity.
Loop-region mutations in CSNK2A1 are associated with higher symptom burden in OCNDS
In 48 individuals with OCNDS, variants in loop regions of CK2α were associated with significantly younger age at diagnosis and higher frequency of hypotonia. Mutations in the glycine-rich loop were linked to significantly higher symptom burden and more non-seizure neurological symptoms.
Glycine as an indirect structural inducer enhances piezoelectric performance of silk fibroin patches for wireless facial micromotion monitoring during sleep
The study developed a fully green bioelectronic piezoelectric film using silk fibroin, where glycine was used as an indirect structural inducer to regulate secondary structure and increase β-sheet content, significantly improving piezoelectric performance. This enabled a soft, ultrathin patch sensor for dual-channel, real-time tracking of rapid eye movements and nasal flaring during sleep. The system demonstrated superior softness, micron-scale thickness, heightened force sensitivity, and stable signal response.
Glycine as an indirect structural inducer enhances the piezoelectric performance of silk fibroin patches for real-time facial micromotion tracking during sleep
The study developed a fully green bioelectronic piezoelectric patch using silk fibroin regulated by glycine to increase β-sheet content and molecular alignment, improving piezoelectric performance. The patch enabled dual-channel, real-time wireless monitoring of rapid eye movements and nasal flaring during sleep with high conformability and biocompatibility.
Engineered probiotic Escherichia coli Nissle produces sustained guanidinoacetic acid titers that may mitigate cognitive effects of sleep deprivation
The study engineered the human probiotic Escherichia coli Nissle to continuously produce guanidinoacetic acid (GAA), which is converted to creatine in the liver. Under laboratory conditions, a standard dose of 10^12 cells produced 41 ± 7 mg GAA per hour, potentially providing a sustained creatine source to improve cognitive performance during sleep deprivation.