Amino Acids · Glycine

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.

2 min readUpdated Jul 8, 20261 RCTsView structured evidence →
Evidence Score44/100
Human RCT★★☆☆☆
Meta-analysis☆☆☆☆☆
Mechanism★★★★★
Safety★★★★
Confidencelow

This article is automatically generated from the structured evidence profile behind the claim above. Scores reflect the quality and quantity of available research, not clinical advice.

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. The current body of evidence comprises 1 study, including 1 randomized controlled trial. EvidenceHub rates the overall confidence at 44/100 (low).

The Claim

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.

This conclusion is most relevant to: 9 males and 7 females, age 24 ± 3 years, body mass 69.8 ± 11.6 kg, stature 170.8 ± 9.1 cm, healthy adults..

What the Research Shows

The conclusion draws on 1 linked study. Highlights from the cited literature:

  • Nutritional Modulation of Sleep Latency, Duration, and Efficiency: A Randomized, Repeated-Measures, Double-Blind Deception Study. (Medicine and science in sports and exercise, 2023) —

How It Works

The proposed biological pathway:

  • Ingestion of nutritional blend containing tryptophan, glycine, magnesium, tart cherry powder, and l-theanine
  • Upregulation of key sleep-related metabolites including 6-sulfatoxymelatonin, D-serine, and L-glutamic acid
  • Neurophysiological modulation of the sleep/wake cycle
  • Reduced sleep onset latency, increased total sleep time, increased sleep efficiency, and reduced morning sleepiness

Who Might Benefit

Evidence fit by population:

  • 9 males and 7 females, age 24 ± 3 years, body mass 69.8 ± 11.6 kg, stature 170.8 ± 9.1 cm, healthy adults.

Limitations & Caveats

Important context when interpreting this evidence:

  • Small sample size (n=16) limits generalizability
  • Short intervention period (3 days) may not reflect long-term effects
  • Dosage of individual components in the blend not specified in abstract
  • Free living conditions may introduce uncontrolled confounding variables despite standardization efforts

Frequently Asked Questions

What ingredients were in the sleep blend tested in this study?

The blend contained tryptophan, glycine, magnesium, tart cherry powder, and l-theanine, but the exact dosages of each component were not provided in the abstract.

How much did sleep onset latency improve with the nutritional blend?

Sleep onset latency was reduced by an average of 24 minutes (from baseline) compared to placebo, with a standard deviation of 25 minutes and a statistically significant P-value of 0.002.

Was this study blinded and controlled?

Yes, it was a randomized, repeated-measures crossover, double-blind deception study, meaning participants were blinded to the study's primary outcome (sleep assessment). 75% of participants remained blinded to sleep as the primary outcome.

What objective measures were used to assess sleep?

Objective sleep measures were obtained using actigraphy, which tracked sleep onset latency, total sleep time, and sleep efficiency. Subjective measures included the Pittsburgh Sleep Quality Index, Core Consensus Sleep Diary, and Karolinska Sleepiness Scale.

References

  1. 1.Langan-Evans C, Hearris MA, Gallagher C, Long S, Thomas C, Moss AD, Cheung W, Howatson G, Morton JP. “Nutritional Modulation of Sleep Latency, Duration, and Efficiency: A Randomized, Repeated-Measures, Double-Blind Deception Study..” Medicine and science in sports and exercise, 2023. PMID: 36094342 DOI: 10.1249/MSS.0000000000003040
Disclaimer: This article is auto-generated from structured research data for educational purposes only and is not medical advice. Evidence scores reflect the quality and quantity of available research, not clinical recommendations. Always consult a healthcare professional before starting any supplement or intervention.