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Gamma Oryzanol

Gamma Oryzanol (γ-Oryzanol), a mixture of compounds found notably in rice bran oil, is a promising but unproven cholesterol-lowering agent with some skin health properties. It does not increase testosterone.

Our evidence-based analysis on gamma oryzanol features 34 unique references to scientific papers.

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Last Updated:

How to Take

Recommended dosage, active amounts, other details

The dosages of Gamma-oryzanol used are highly variable, with some studies using a lower dose (50mg once daily or 20mg thrice daily) and other studies using a markedly higher dosage (300-800mg daily). As there are no reliable benefits associated with Gamma-oryzanol supplementation in the first place, it is unsure what dosage should be recommended (if this supplement is to be recommended at all).

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Human Effect Matrix

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The Human Effect Matrix summarizes human studies to tell you what effects Gamma Oryzanol has on your body, how much evidence there is, and how strong these effects are.

Full details are available to Examine members.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-c - - See study
No significant influence on cortisol levels with prolonged supplementation
grade-c - - See study
No significant influence on circulating estrogen levels in healthy men given gamma-oryzanol over a few weeks
grade-c - - See study
No significant alterations in growth hormone following ingestion of gamma-oryzanol
grade-c - Very High See 2 studies
No detectable influences on HDL cholesterol, although rice bran oil (a source of gamma oryzanol) may have a slight positive effect
grade-c - - See study
No significant alterations noted in fasting insulin levels following prolonged ingestion of gamma-oryzanol in healthy persons
grade-c - - See study
Although rice bran oil may reduce LDL cholesterol, there is insufficient evidence to support the role of gamma-oryzanol in this role
grade-c - - See study
Plasma beta-endorphin is unaltered following ingestion of standard doses of gamma-oryzanol
grade-c - - See study
No interactions with power output have been noted with gamma-oryzanol ingestion
grade-c - - See study
No detectable influence on testosterone levels in otherwise healthy men
grade-c - Very High See 2 studies
No significant alterations seen in total cholesterol levels with supplementation
grade-c - - See study
No significant alterations in plasma triglycerides seen with supplementation

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Click here to see all 34 references.