CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-11). 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. 306 · Search date 2026-07-11 · Methodology v0.6

Purple corn cob and husk extract powder,
does it really help with Improvement of dry eyes?

30-Second Summary
C
Evidence Grade C · 47 · Safety unknown
A human trial was conducted, but numerical results and independent replication are not public
What the
research shows
The ingredient developer states that the exact purple corn cob and husk extract at 500 mg/day was evaluated in a 12-week randomized placebo-controlled human trial. However, the sample size, prespecified endpoints, numerical results, and a peer-reviewed human paper are not public, while published evidence consists only of cell and animal work, so the grade is low C.
What the
ads claim
Advertising may connect restored tear volume in animals and the existence of a human trial to a confirmed human dry-eye effect. Public data do not disclose clinical effect size, symptom scores, tear-film findings, or safety results.
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Useful facts when choosing a product

  • The developer-reported human-trial dose was 500 mg/day for 12 weeks.
  • The extract uses purple corn cobs and husks and contains cyanidin-3-O-glucoside.
  • It is not interchangeable with generic purple corn foods or kernel extracts.
  • Long-term safety is unknown because public human safety data are limited.
Gap Measurement · Verdict 306 · C 47
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

PCE-PRO developer materials describe a randomized, placebo-controlled parallel human trial of Korean purple corn cob and husk extract at 500 mg/day for 12 weeks in adults with dry-eye symptoms. No peer-reviewed human paper was identified. The 2023 study by Lee and colleagues reported that a 30% ethanolic extract of the same cob and husk material improved tear volume, corneal surface, and goblet-cell measures in desiccation-stressed cells and a lacrimal-gland-excision rat model, but all authors were employed by the developer.

02

Why this is classified as C (47)

Regulatory recognition itself is not grading evidence, but a human trial of the exact ingredient was conducted, so the grade is not unknown. Positive evidence is confined to one manufacturer-specific proprietary product, no full results or independent replication are public, and published evidence is manufacturer preclinical work, supporting C with 47 points.

Counterpoint. The specific 500 mg/day ingredient was evaluated in a 12-week human trial and has preclinical plausibility.

Rejudgment record. Reassessment (cross-check reflected) — Regulatory recognition is not grading evidence, but a 12-week randomized human trial of the exact manufacturer-specific 500 mg/day product is confirmed; sample size, endpoints, numerical results, and a peer-reviewed paper are absent, and there is no independent replication while public evidence is limited to manufacturer preclinical work

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
PCE-PRO human clinical studyDeveloper-disclosed randomized placebo-controlled parallel trial; results not public12Associated with the ingredient developerDry-eye symptoms in adultsOnly evaluation at 500 mg/day was disclosed; numerical results were not available.Key
Lee JM et al. 2023Cell and lacrimal-gland-excision rat study5Supported by the Korean Ministry of SMEs and Startups; all authors employed by MEDIENCETear volume, cornea, goblet cells, and inflammationPurple corn cob and husk extract improved preclinical measures.Supportive
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Receipt — 1 References

All 1 cited sources were verified for existence at the original page (as of 2026-07-11).

Lee JM, Choi A, Lee HH, Park SJ, Kim BH. 2023. Purple Corn Extract Improves Dry Eye Symptoms in Models Induced by Desiccating Stress and Extraorbital Lacrimal Gland Excision. Nutrients. 15(24):5063. PMID: 38140323. DOI: 10.3390/nu15245063.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-11 · Corrections: none

Cite this verdict

Purple corn cob and husk extract powder × Improvement of dry eyes Evidence Grade C card
[Chamgap] Purple corn cob and husk extract powder × Improvement of dry eyes — Evidence Grade C·47. 1 cited sources checked. Source: https://health-receipt.pages.dev/en/verdicts/eye/purple-corn-cob-husk-dry-eye/ · 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.