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APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-15). The draft was written by AI, the existence of all 1 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 349 · Search date 2026-07-15 · Methodology v0.6

Rice bran ethanolic extract,
does it really help with Improved sleep duration, sleep efficiency, and sleep onset?

30-Second Summary
C
Evidence Grade C · 50 · Safety caution
Rice bran ethanolic extract has a two-week polysomnographic signal, but evidence beyond one specific ingredient trial is limited
What the
research shows
The trial enrolled 50 adults with sleep disturbance but analyzed 42, with 21 per group. After 1,000 mg/day for two weeks, polysomnographic total sleep time, efficiency, and latency improved, but between-group PSQI was null and the evidence came from one S&D-supplied lot with company coauthors, resulting in C.
What the
ads claim
Marketing may expand the finding into immediate sleep, guaranteed deep sleep, or replacement of hypnotic medication. Direct evidence is a two-week adjunctive trial in adults with disturbed sleep that excluded severe insomnia; it does not establish treatment of chronic insomnia or long-term benefit.
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Useful facts when choosing a product

  • The studied material was a water-ethanol rice bran extract powder standardized to 4.5 mg/g of gamma-oryzanol.
  • The trial dose and the Korean functional-ingredient daily intake are 1 g/day of rice bran ethanolic extract.
  • Korean products include one-sachet formulations delivering 1 g and products sold by companies including Amway.
  • The study powder contained sodium caseinate, so milk allergy and the actual product label should be checked.
Gap Measurement · Verdict 349 · C 50
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Um and colleagues in 2019 randomized 50 adults with sleep disturbance but analyzed 42, with 21 per group. After rice bran extract at 1,000 mg/day for two weeks, polysomnographic total sleep time at p=0.019 and sleep efficiency at p=0.010 were positive, while sleep latency at p=0.047 was marginal. Between-group PSQI, Epworth Sleepiness Scale, and fatigue outcomes were null. The ingredient was one S&D-supplied lot standardized to 4.5 mg/g of gamma-oryzanol, company researchers were coauthors, and no independent replication exists.

02

Why this is classified as C (50)

Polysomnographic total sleep time, efficiency, and latency were positive, but only 42 participants were analyzed, 21 per group, for two weeks; latency at p=0.047 was marginal and between-group PSQI was null. One S&D-supplied lot, company coauthors, and no independent replication support C with 50 points.

Counterpoint. Short-term objective sleep improvement is confirmed for the exact standardized ingredient at 1 g/day.

Rejudgment record. Reassessment (cross-check reflected) — A two-week RCT enrolled 50 and analyzed 42 participants; polysomnographic total sleep time and efficiency were positive and latency was marginal at p=0.047, but PSQI was null and the study used one S&D-supplied lot with company coauthors and no independent replication

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Increased total sleep timeCA two-week polysomnography trial enrolled 50 and analyzed 42 participants and found an increase versus placebo, but independent replication is absent.
Improved sleep efficiencyCThe same single trial was positive, limited to one standardized ingredient.
Reduced sleep latencyCPolysomnographic sleep latency was marginally significant in one two-week trial.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Um MY et al. 2019Randomized double-blind placebo-controlled polysomnographic trial2Ingredient supplied by S&D with company researchers as coauthorsPolysomnographic sleep latency, total sleep time, sleep efficiency, and stages; PSQI, sleepiness, and fatiguePolysomnographic total sleep time (p=0.019) and efficiency (p=0.010) were positive and latency at p=0.047 was marginal, while between-group PSQI was null.Key, single product
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Receipt — 1 References

All 1 cited sources were verified for existence at the original page (as of 2026-07-15).

Um MY, Yang H, Han JK, et al. Rice bran extract supplement improves sleep efficiency and sleep onset in adults with sleep disturbance: A randomized, double-blind, placebo-controlled, polysomnographic study. Sci Rep. 2019;9:12339. PMCID: PMC6710429. DOI: 10.1038/s41598-019-48743-8.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-15 · Corrections: none

Cite this verdict

Rice bran ethanolic extract × Improved sleep duration, sleep efficiency, and sleep onset Evidence Grade C card
[Chamgap] Rice bran ethanolic extract × Improved sleep duration, sleep efficiency, and sleep onset — Evidence Grade C·50. 1 cited sources checked. Source: https://health-receipt.pages.dev/en/verdicts/sleep/rice-bran-ethanolic-extract/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.