Gamma Oryzanol

What is it?

Gamma oryzanol is a naturally occurring mixture of plant chemicals called sterols and ferulic acid esters.

Some evidence suggests that gamma oryzanol increases testosterone levels, stimulates the release of endorphins (pain-relieving substances made in the body), and promotes the growth of lean muscle tissue.¹ Supplementation with gamma oryzanol for nine weeks did not influence exercise performance in male weight lifters.²

Where is it found?

Gamma oryzanol is a natural component of rice bran, corn, and barley oils. Gamma oryzanol is also available as a supplement.

Gamma oryzanol has been used in connection with the following condition (refer to the individual health concern for complete information):

Rating	Health Concerns
	Gastritis
	Athletic performance
Reliable and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit. For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

How much is usually taken?

Much of the human research with gamma oryzanol used 300 mg per day. Healthy people do not appear to need this supplement.

Are there any side effects or interactions?

Some research suggests that gamma oryzanol taken in moderately high amounts (up to 600 mg per day) for several months can cause dry mouth, sleepiness, hot flushes, irritability, and light headedness in some individuals.³

At the time of writing, there were no well-known drug interactions with gamma oryzanol.

References

1. Rosenbloom C, Millard-Stafford M, Lathrop J. Contemporary ergogenic aids used by strength/power athletes. J Am Diet Assoc 1992;92:1264-5.

2. Fry AC, Bonner E, Lewis DL, et al. The effects of gamma-oryzanol supplementation during resistance exercise training. Int J Sport Nutr 1997;7:318-29.

3. 34. Takemoto T, Miyoshi H, Nagashima H. Clinical trial of Hi-Z fine granules (gamma-oryzanol) on gastrointestinal symptoms at 375 hospitals (Japan). Shinyaku To Rinsho 1977;26 [in Japanese].

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The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over-the-counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2005.

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