Black soybean seed-coat polyphenol extract, 100 mg,
does it really help with Improved sleepiness-on-rising score at 12 weeks?
research showsGrade C. In a 12-week trial of 64 healthy adults dissatisfied with sleep quality, the primary OSA-MA sleepiness-on-rising score improved versus placebo in the full FAS1 analysis, P<.05. The main paper displayed estimated marginal means with standard errors in a figure but did not provide exact group values or a 95% confidence interval in the text.
ads claimThis is not evidence that whole black soybeans or ordinary soy foods improve sleep. It is a narrow result for 100 mg of a specific extract taken in the evening for 12 weeks on one rising-sleepiness score.
Useful facts when choosing a product
- Major constituents include polyphenols such as proanthocyanidins and epicatechins.
- The paper did not provide exact group values or a 95% CI for the primary endpoint in its text.
- The total sample of 64 was below 200.
What the research actually shows
In Japan, 64 healthy adults dissatisfied with sleep quality were randomized 32/32 to 100 mg black soybean seed-coat extract after the evening meal or placebo for 12 weeks. The primary endpoint was change in OSA-MA sleepiness on rising at week 12. The paper said no specific funding was received, but R.A., T.M., and K.M. were Fujicco employees, the company supplied study food to the contract site, and company employees participated in conceptualization, methods, analysis, data management, and drafting. No specific cash grant is not the same as no conflict of interest. Registration was UMIN000051261.
Why this is classified as C (50)
One 64-person trial with manufacturer employees involved in design, analysis, and writing found a positive self-reported rising-sleepiness score, giving C with 50 points.
Counterpoint. Without exact effect estimates and a confidence interval in the text, interpretation beyond statistical positivity is limited.
Rejudgment record. Cross-check applied — Full-FAS1 primary sleepiness-on-rising result, 64-person size, and Fujicco employee involvement throughout the study
| Endpoint | P | Patient-reported treatment goal - the symptom is the goal |
| Replication | R1 | Single confirmatory trial |
| Independence | I0 | Evidence comes only from manufacturer studies |
| Effect size | E+ | Meets the clinically important threshold |
The scoring table and the verdict agree (C).
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) | Grade | Basis |
|---|---|---|
| Improved sleepiness-on-rising score | C | The full FAS1 primary analysis had P<.05. |
| Improved overall sleep quality | ? | This verdict is limited to one rising-sleepiness score, not that broader claim. |
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Study 1 | Double-blind randomized placebo-controlled parallel trial | 32 | No specific funding declared; three Fujicco employee authors, company-supplied study food, and company participation in design, analysis, and writing | Change in OSA-MA sleepiness-on-rising score at 12 weeks | Improved versus placebo in full FAS1, P<.05; exact group values and 95% CI not provided in text | Full-analysis primary endpoint |
Receipt — 1 References
All 1 cited sources were verified for existence at the original page (as of 2026-08-26).
Final verification and publication gate: Codex · Verification cutoff: 2026-08-26 · Corrections: none
Cite this verdict
[Chamgap] Benefit of Black Soybean Seed-Coat Extract for Sleepiness on Rising — Evidence Grade C·50. 1 cited sources checked. Source: https://chamgap.com/en/verdicts/sleep/black-soybean-seed-coat-extract-sleepiness-on-rising/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
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.