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THE LEDGER

Every study we weighed.
Both verdicts.

16 studies, 5 of which made the formula. Most companies publish only the evidence that flatters them; the rejections are where the standard actually shows. Every row links its original source. Explore the ingredient evidence and see how the choices fit the Dayspan Glycine formula.

Machine-readable copy: /studies.json

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IngredientStudyDesignFunding, as disclosedVerdict
GlycineYamadera et al. 2007 · Inagawa et al. 2006 (Sleep and Biological Rhythms)3 g before bed shortened time to fall asleep and time to reach slow-wave sleep; sleep architecture unchanged.Human polysomnography (sleep lab)Authors affiliated with Ajinomoto, an amino-acid manufacturerincluded
Magnesium bisglycinateSchuster et al. 2025 (Nature and Science of Sleep), N=155Insomnia-severity scores improved vs placebo — a small effect; every secondary measure showed no difference.Randomized controlled trialAcademicincluded
L-theanineBulman et al. 2025 (Sleep Medicine Reviews), 18 RCTs, N=897Self-rated sleep quality improved; objective sleep recordings did not move.Independent meta-analysisNo industry tiesincluded
GABAYamatsu et al. 2016 (Food Science and Biotechnology), N=10100 mg shortened EEG-measured sleep latency in a one-week crossover of 10 poor sleepers; most other outcomes did not reach significance. Historical research only: GABA is not included in the current five-active Glycine formula.Human EEG, single-blind crossoverAuthored by employees of the ingredient manufacturerleft out by design
Saffron extractLopresti et al. 2021 (Sleep Medicine), N=12028 mg one hour before bed improved sleep-diary ratings vs placebo over 28 days; no sleep-lab measurement. The 2020 trial (N=63) dosed 14 mg twice daily.Randomized controlled trial, sleep-diary endpointsFunded by the extract's manufacturerincluded
ZincSaito et al. 2017 (Molecular Nutrition & Food Research), N=120The trial supplied zinc in a food, not as the Dayspan formula. That material difference limits transfer to this product; the finished five-active combination has not been clinically tested.Human trial with actigraphyIndustry-authoredincluded
ApigeninPrimary GABA-A electrophysiology (four independent labs)No human sleep trial of isolated apigenin exists at any dose; ~99% water-insoluble; the bench work shows inhibition, not enhancement.Bench electrophysiologyrejected
AshwagandhaNIH LiverTox monographBest sleep-trial evidence of anything we rejected — cut on safety: graded a likely cause of clinically apparent liver injury; banned in Danish food supplements.Safety databaserejected
MelatoninSleep-architecture research (slow-wave suppression, spindle increase)A timing signal, not a sedative; pooled sleep-onset effect ≈7 minutes. It does change sleep architecture, contrary to the industry line.Human sleep researchleft out by design
ValerianValerenic-acid mechanism and human pharmacokineticsReal mechanism, unreachable dose: human blood levels miss the functional requirement by roughly a thousandfold.Mechanism + human PKrejected
Alpha-ketoglutarateOngoing placebo-controlled trial (NCT05706389)No human or animal sleep evidence at all; its actual literature is lifespan and 'biological age' work.Ongoing randomized trial — no sleep endpointrejected
Resveratrol / polydatinFour human trials with sleep as a secondary endpointAll four null. The one title suggesting otherwise was an NAC + lactoferrin + 59 mg resveratrol combination in interferon-treated hepatitis C patients. Also inhibits warfarin clearance.Human trials, secondary endpointsrejected
Palmitoylethanolamide (PEA)Pre-registered randomized sleep trial with actigraphyA fair test, failed: all three pre-registered primary endpoints missed. The easiest possible exclusion.Randomized controlled trial, objective measurementrejected
Ellagic acid / urolithin ATwo sleep trials in diagnosed patientsOne reports a baseline sleep efficiency of 8.8% — physiologically impossible, and quoted unchallenged in a peer-reviewed review. Urolithin A has no sleep endpoint in any trial.Trials in diagnosed patient populationsrejected
Myo-inositolSingle randomized trial, 2 g nightly, third-trimester pregnancyA real subjective result, never replicated in ordinary poor sleepers. Citing it to you would be borrowed evidence.Randomized trial in one specific populationrejected
Oxaloacetate2024 RESTORE ME randomized trial (ME/CFS, fatigue endpoint)Sleep appears nowhere as an outcome. Fatigue and sleepiness feel adjacent, which is exactly why the distinction matters.Randomized fatigue trial in a disease populationrejected

Study results and limitations belong together. These verdicts concern ingredient choices for Dayspan Glycine, not every possible use of an ingredient. The finished Dayspan Glycine combination itself has not been clinically tested.

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