Gamma-oryzanol,
does it really help with Cholesterol, menopause, autonomic nervous system?
research showsGamma-oryzanol has human studies. Cholesterol studies assessed blood-lipid surrogates rather than clinical events, while menopause and autonomic studies are old and centered on subjective ratings. Exercise and testosterone claims were not supported in a direct placebo-controlled RCT. Overall evidence is lower-end C.
ads claimAdvertising ranges widely across 'autonomic nervous system stabilization,' 'menopause,' 'cholesterol,' 'rice-bran antioxidant,' and even 'male hormones.' Compared with ingredient background and traditional use, clinical trials are weak.
Useful facts when choosing a product
- Gamma-oryzanol is not a single substance but a mixture of several ferulate esters.
- Rice bran oil, brown rice, phytosterols, and gamma-oryzanol capsules should have their evidence separated.
- Long-term high-dose safety data are limited.
- When combined with or substituted for menopausal-symptom treatments, clinician judgment is needed.
What the research actually shows
A 1980s Japanese multicenter double-blind cholesterol trial compared 300 mg with 75 mg; 75 mg was a low-dose control, not a true placebo. It measured blood lipids, not clinical events. Oimatsu 1981 was N=20, 300 mg/day for 16 weeks, single-arm; Ohsawa 1983 was N=17, 300 mg/day for 16 weeks, single-arm. Sasaki 1990 (PMID 1974170) was a non-RCT single-arm before-and-after study, N=20, using 100 mg three times daily for 16 weeks. The Kushima 1976 and 1985 menopause and autonomic double-blind trials are very old, used subjective global-improvement ratings, and have unverified N, allocation, and funding. Nakazawa 1977 gave 300 mg/day for 2 weeks to 21 patients and rated 8 markedly effective, 5 effective, 5 slightly effective, and 3 ineffective, but no control group was verified. Fry 1997 (PMID 9407258, N=22) used 500 mg/day for 9 weeks in a double-blind placebo-controlled trial and found no between-group effect on strength, testosterone, GH, or cortisol. Eslami 2014 (PMID 25109720, N=30) used 600 mg/day for 9 weeks; bench press and leg curl were positive, while body composition was null. Rice bran oil, phytosterol, Femoston, and monacolin combination results are not attributed to gamma-oryzanol alone.
Why this is classified as C (42)
Under rule ①, cholesterol is capped at C because it centers on surrogates. Menopause and autonomic evidence is C/C− because it is old, subjective, and of unverified independence; exercise and testosterone are D because direct RCT evidence was null. Overall: lower-end C, 42 points. Japanese approval is regulatory-neutral under rule ④.
Counterpoint. Modern placebo-controlled clinical-event trials or independent trials with objective primary endpoints and disclosed allocation and funding could change the position of the subclaims.
Rejudgment record. Reassessment (?→C) — This is not ? because direct human trials exist. Cholesterol is capped at C under rule ① because it relies on surrogates; menopause and autonomic evidence is C/C− because it is old, subjective, and of unverified independence; exercise and testosterone are D because direct RCT evidence was null. Overall is lower-end C. Regulatory recognition is neutral under rule ④.
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 |
|---|---|---|
| Cholesterol | C | Old Japanese double-blind dose comparison (300 vs 75 mg) improved lipid surrogates; not a true placebo control |
| Menopause/autonomic | C | Double-blind trials exist but are old, based on subjective global improvement, with unverified independence |
| Exercise/testosterone | D | Strength, testosterone, and other measures null in a direct RCT (Fry 1997) |
Cross-check — Codex and Claude
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Study 1 | Double-blind dose comparison; no true placebo | Unverified | Blood-lipid surrogates | Compared 300 mg with a 75 mg low-dose control and did not assess clinical events. | Core cholesterol C evidence | |
| Sasaki et al. 1990 (PMID 1974170) | Single-arm before-and-after; not an RCT | 20 | Unverified | Blood lipids and apolipoproteins | Some markers changed after 300 mg/day for 16 weeks, but there was no control group. | Supporting |
| Kushima 1976·1985 | Old double-blind trials | Unverified | Subjective global improvement | Bibliographically real, but N, allocation, and funding verification is limited. | C/C− | |
| Fry 1997 (PMID 9407258) | Double-blind randomized placebo-controlled RCT | 22 | Unverified | Strength, testosterone, GH, and cortisol | No between-group effect after 500 mg/day for 9 weeks. | Direct exercise and testosterone D evidence |
| Eslami 2014 (PMID 25109720) | Double-blind placebo-controlled trial | 30 | Unverified | Strength and body composition | Two strength tests were positive and body composition was null after 600 mg/day for 9 weeks. | Conflicting support |
| Study 6 | Regulatory/context material; not an RCT | Mixed | Approval and combination products | Neutral under rule ④; combination outcomes are not attributed to the single ingredient. | Separate |
Receipt — 6 References
Of 6 cited sources, 6 had limited original-page access (blocked or summary-only) and were verified via index/summary, marked partial; the rest were verified at the original page. As of 2026-07-12.
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-12 · Corrections: 1
Correction log — 1
Corrections applied to this verdict, in chronological order. Changes are logged, not erased.
- 2026-07-11 · Re-adjudication (grade changed) — The previous 'judgment deferred (?)' cited a lack of verifiable human RCTs, but single-ingredient double-blind trials for cholesterol/menopause and direct RCTs on exercise/testosterone (Fry 1997, null) exist. Because human trials exist, this is C, not '?' (cholesterol capped at C by surrogate/old/75mg-control/manufacturer data; testosterone/exercise D from a null RCT). Component-analysis and Wikipedia citations were replaced with the actual trials. 2026-07-11 internal audit. (grade ?→C)
Cite this verdict
[Chamgap] Gamma-oryzanol × cholesterol, menopause, autonomic nervous system — Evidence Grade C·42. 6 cited sources checked. Source: https://chamgap.com/en/verdicts/womens/gamma-oryzanol-cholesterol-menopause-autonomic/ · 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.