Gamma Oryzanol: A Comprehensive Reference
1. Identity and Chemical Nature
Nomenclature and Botanical Source
γ-Oryzanol (gamma oryzanol) is a mixture of lipids derived from rice (Oryza sativa), occurring mainly in the fat fraction of rice bran and rice bran oil. Originally thought to be a single chemical compound, it is now known to be a mixture of ferulic acid esters of phytosterols and triterpenoids, particularly cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, and campesteryl ferulate, which together account for approximately 80% of γ-oryzanol. Minor constituents include Δ7-stigmastenyl ferulate, stigmasteryl ferulate, Δ7-campestenyl ferulate, Δ7-sitostenyl ferulate, sitosteryl ferulate, compestanyl ferulate, and sitostanyl ferulate.
Its main components are esters of trans-ferulic acids and plant sterols, which include more than 23 different steryl ferulates, with cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesteryl ferulate, and β-sitosteryl ferulates being mainly represented in most cultivars. 24-methylenecycloartanyl ferulate and cycloartenyl ferulate are categorized as triterpene alcohol type, while β-sitosteryl ferulate and campesteryl ferulate are categorized as phytosterol type.
Although the constituents of γ-oryzanol were identified as steryl esters of ferulic acid, more recent work has revealed the presence of caffeate esters of cycloartenol and campesterol as well.
Physicochemical Properties
Physicochemically, γ-oryzanol is a white to off-white, odorless, and tasteless crystalline powder that is virtually insoluble in water but with a slight solubility in alkalinized methanol and ethanol. This behaviour is due to the weakly amphiphilic nature of γ-oryzanol, which features a phenolic hydroxyl group that acts as a weak acid, along with a long hydrophobic tail. In an alkaline environment, γ-oryzanol converts into a γ-oryzanol salt, able to dissolve in methanol/ethanol.
Distribution in Nature
Steryl ferulates have been identified in rye, corn, triticale, barley, and wheat, but their richest source is rice, and specifically rice bran oil (RBO). The most abundant steryl ferulates in RBO, comprising almost 95% of γ-oryzanol, are campesterol, β-sitosterol, cycloartenol, and 24-methylenecycloartenol esters. It can also be found in lesser amounts in barley, maize, wheat, oats, asparagus, tomatoes, peas, berries, olives, vegetables, fruits (particularly citrus fruits), and several other foods.
The composition and concentration of γ-oryzanol vary significantly among rice varieties and are influenced by genetic, environmental, and technological factors. Varietal studies have confirmed this variability: the overall variability of gamma-oryzanol concentration within rice varieties has been reported from 1.56 g/kg to 3.19 g/kg.
2. Extraction, Preparation, and Commercial Forms
The oil extracted from rice bran, a by-product of brown rice processing, is abundant in valuable bioactive substances. One of its main ingredients is gamma-oryzanol, which is a mixture of phytosterol esters and ferulic acid.
Advances in extraction methods, including traditional solvent extraction and innovative approaches such as supercritical fluid extraction, have improved yield and purity, supporting its use in functional foods, nutraceuticals, and cosmetics. Different strategies to improve the yield and purity during extraction have been developed including extraction with different solvents, liquid–liquid phase extraction, solid phase extraction, supercritical fluid extraction, microwave-assisted (MAE), and enzymatic-assisted extraction (EAE).
In supercritical fluid extraction, optimal conditions identified at 500 bar and 62°C yielded 36.6 mg of γ-oryzanol per gram of extract. Compared with conventional hexane extraction, supercritical fluid extraction showed similar global yield but higher selectivity and extraction yield for γ-oryzanol.
Commercially, gamma oryzanol is available in several forms: as a purified powder ingredient in dietary supplement capsules and tablets; as an ingredient in rice bran oil used as a food and cooking oil; and incorporated in cosmetic and topical preparations. Approximately 7,500 tons of gamma oryzanol are processed from rice bran in Japan each year. Rice bran extracts are also used in the cosmetic industry.
3. Traditional and Historical Use
Isolation, extraction, and purification of gamma oryzanol were first reported in the mid-1950s. It has been used in Japan as a medicine since 1962, first to treat anxiety and later in menopause.
It has been sold in Japan as a medicine since 1962, first to treat anxiety and later in menopause. Gamma oryzanol and rice bran oil therapy have been used to manage elevated cholesterol and triglyceride levels since the late 1980s.
It has been approved in Japan for several conditions, including menopausal symptoms, mild anxiety, stomach upset, and high cholesterol. In the United States, it is widely used as a sports supplement and for reducing cholesterol.
While the isolated compound itself dates to mid-twentieth century Japan, the use of its source material is considerably older. While gamma oryzanol itself was isolated and studied in Japan in the 1950s, the medicinal use of its source — rice bran and rice bran oil — has a much longer history. In traditional Japanese Kampo medicine, rice bran was used in formulations to nourish the body, improve digestion, and reduce internal heat, and its oil was applied for skin conditions and as a general tonic. In Ayurveda, rice and its byproducts were used to balance digestion, calm inflammation, and support reproductive health, although gamma oryzanol was not specifically identified in this context.
Gamma oryzanol has been extensively used as an antioxidant, antiulcerogenic, antineoplastic, antidiabetic, and antiallergic drug for many years in Japanese pharmacological practice. Therapeutic use of gamma oryzanol has also been approved in Japan for inflammation and nervousness.
4. Key Constituents and Mechanisms of Action
Component Structure
Chemically, γ-oryzanol is a mixture of structurally related components, and specifically esters of ferulic acid with phytosterols and triterpene alcohols, also referred to as steryl ferulates. In the human body, gamma oryzanol can be metabolized to ferulic acid and steryl ferulates closely similar in structure to cholesterol. Both the parent steryl ferulates and the metabolite ferulic acid are considered to contribute to the compound's biological activities.
Antioxidant Mechanisms
Gamma-oryzanol, a phytosteryl ferulate mixture extracted from rice bran oil, has antioxidant properties and is often used in cosmetic formulations as a sunscreen. It functions as an organic radical scavenger, capable of preventing lipid peroxidation as demonstrated in various in vitro model systems, including scavenging of stable DPPH radicals, hydroxyl radicals, and superoxide radicals. Gamma-oryzanol possesses a clear, dose-dependent DPPH scavenging activity, although it is weaker than alpha-tocopherol used as an antioxidant reference.
From a mechanistic point of view, ORY exerts its antioxidant effect by scavenging free radicals and activating the Nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Confirming this, as a consequence of Nrf2 nuclear translocation, its target genes are transactivated. Research found that gamma oryzanol induced the transient transcription of HO-1, NQO1, and GSS genes by increasing their protein expression.
Cholesterol-Lowering Mechanisms
Gamma-oryzanol is not absorbed well in the gut. Because of this, it may reduce cholesterol levels by reducing how much cholesterol is absorbed from foods. These lipid modulations align with the mechanistic actions of γ-oryzanol, which include inhibition of cholesterol absorption and HMG-CoA reductase (HMGCR) activity, alongside regulation of lipid metabolism pathways.
Anti-Inflammatory Mechanisms
Preclinical studies indicate that γ-oryzanol targets multiple molecular pathways, including activation of AMP-activated protein kinase (AMPK), upregulation of peroxisome proliferator-activated receptor-α (PPARα), inhibition of nuclear factor-κB (NF-κB), and promotion of glucose transporter type 4 (GLUT4) translocation. These mechanisms collectively improve glucose and lipid metabolism, enhance insulin sensitivity, and reduce inflammation.
Neuroendocrine Mechanisms
Some evidence emphasizes the effects of gamma oryzanol on the brain and its role in modulating the function of the hypothalamus and anterior pituitary gland. Phytosterols present in gamma oryzanol play a critical role in the synthesis of essential biomolecules such as sex hormones, resulting in the production of steroidal hormones. Studies in animal models have also found anxiolytic effects: gamma oryzanol potentially blocked high-fat diet-induced anxiety-like behaviors via significant improvement of primary behavioral parameters, with findings strongly suggesting that gamma oryzanol exerts anxiolytic-like effects possibly through downregulation of dopamine and via expression of pro-inflammatory cytokines TNF-α and IL-1β.
Gut Microbiota
Recent evidence suggests that γ-oryzanol may influence the composition and activity of the gut microbiota, highlighting a novel mechanism underlying its health benefits. This area of research remains in early stages, with most findings from preclinical models.
Bioavailability
Gamma oryzanol appears to be very poorly absorbed from the gastrointestinal tract. Published scientific studies suggest that these compounds are poorly absorbed; furthermore, animal studies indicate that when injected subcutaneously or intravenously, they may induce antianabolic or catabolic activity. Normally, less than 5% of orally consumed phytosterols are absorbed from the intestinal tract, with the majority excreted in the feces. Despite limited systemic bioavailability, γ-oryzanol has been detected in multiple organs upon long-term administration of rice bran oil, including the liver, brain, kidney, spleen, muscle, mesenteric fat, and perirenal fat, suggesting that once ingested, it is distributed widely in the body. γ-Oryzanol exhibits antioxidant, neuroprotective, and antidepressant properties, but its clinical application is restricted due to its water-insoluble properties, which lead to poor oral bioavailability.
5. Scientific Evidence by Area of Use
5.1 Dyslipidemia and Cardiovascular Health
This is the most extensively researched area for gamma oryzanol in humans. Clinical studies reveal modest yet significant cholesterol-lowering effects, with evidence showing that supplementation can reduce total cholesterol, LDL cholesterol, and triglyceride levels in hypercholesterolemic patients.
One of the most commonly cited individual clinical studies involves dyslipidemic schizophrenic patients: the subjects were 20 chronic schizophrenic patients with dyslipidemia who had been receiving neuroleptics for a mean of ten years. Each patient was given 100 mg of gamma oryzanol three times daily (300 mg/day total) for 16 weeks. Total cholesterol decreased significantly from 204 to 176 mg/dL, and LDL cholesterol decreased from 124 to 101 mg/dL at week 12. HDL cholesterol levels showed minimal change (36.1 mg/dL at baseline vs. 35.9 mg/dL at week 12).
A more recent randomized controlled study reported more substantial outcomes: a randomized, double-blind, placebo-controlled study demonstrated a 19.3% reduction in LDL-C and a 29.3% increase in HDL-C over three months in adults with mild dyslipidemia using combined supplementation.
A 2025 systematic review covering clinical trials summarized: clinical trials, primarily involving adults with type 2 diabetes, obesity, dyslipidemia, or postmenopausal women (aged 30–70 years, mixed ethnicities), report that γ-oryzanol reduces total cholesterol by 10–15%, LDL-C by 8–12%, and triglycerides by variable amounts.
Preliminary evidence, including small double-blind, placebo-controlled trials, suggests that the gamma oryzanol portion of rice bran oil may contribute an additional cholesterol-lowering benefit beyond the effects of the fatty acids.
Beyond lipid lowering, γ-oryzanol exerts pleiotropic effects on arterial health by influencing inflammatory and oxidative pathways involved in atherosclerosis progression, highlighting its multi-target therapeutic potential in cardiovascular medicine.
Evidence strength: The generalizability of current findings is limited by small sample sizes, inconsistent dosing regimens, and underrepresentation of diverse populations. Large-scale, well-designed clinical trials are needed to validate its efficacy, optimize dosing, and assess long-term safety compared to standard therapies. The existing body of evidence is promising but remains preliminary to moderate in strength.
5.2 Metabolic Syndrome, Diabetes, and Insulin Sensitivity
Clinical evidence supports γ-oryzanol's utility in metabolic syndrome management, where it improves insulin sensitivity, enhances glucose metabolism, and modulates adipokine profiles. Studies involving patients with type 2 diabetes have shown that daily γ-oryzanol intake reduces systemic inflammatory markers such as C-reactive protein (CRP), interleukin-6 (IL-6), and interferon-gamma (IFN-γ), indicating its anti-inflammatory efficacy in metabolic contexts.
A 2025 systematic review of preclinical (animal model) studies on diabetes: the synthesized findings indicate that γ-oryzanol exerts beneficial effects on glycemic control by enhancing insulin secretion and sensitivity, as well as by reducing fasting blood glucose levels. Additionally, γ-oryzanol demonstrates antioxidant activity by elevating endogenous antioxidant enzyme levels and decreasing oxidative stress markers. Its lipid-modulatory effects include the elevation of beneficial lipid fractions and the reduction of atherogenic lipids, thereby alleviating diabetic dyslipidemia. Moreover, γ-oryzanol exhibits anti-inflammatory properties through the downregulation of proinflammatory biomarkers.
Endoplasmic reticulum (ER) stress results in misfolded protein accumulation and leads to pancreatic β-cell death by apoptosis. Gamma oryzanol decreases the expression of ER stress-responsive genes and consequently enhances β-cell insulin production. In addition, it improves the adipocyte production of adiponectin.
Evidence strength: Despite promising results in preclinical models, further high-quality investigations, particularly well-designed clinical trials, are essential to validate these findings. Evidence in humans is limited and largely derived from small trials or secondary outcomes.
5.3 Menopausal Symptoms
γ-Oryzanol has demonstrated clinical benefits in alleviating menopausal symptoms. This application has one of the longest clinical track records, as it underpinned the original Japanese pharmaceutical approval of the compound.
A 2024 clinical study assessed the combination of gamma oryzanol with hormone therapy: in this study, the total effective rate was higher in the observation group than in the control group, suggesting that the treatment scheme of γ-oryzanol combined with Femoston was significantly effective in enhancing curative effects in women with perimenopausal syndrome.
No significant side effects have been produced in experimental and clinical studies. In addition to being helpful in improving the symptoms of menopause, gamma-oryzanol has also been shown to be quite effective in lowering blood cholesterol and triglyceride levels.
Evidence strength: Early Japanese clinical studies supported approval for this indication, but many of these trials are older and lacked rigorous placebo controls by modern standards. Meaningful evidence supporting the use of gamma oryzanol for menopausal symptoms is still emerging, and more studies are necessary.
5.4 Athletic Performance and Body Composition
Gamma oryzanol is used by some athletes based on early reports that suggested it enhances muscle growth and sports performance. Throughout the world γ-oryzanol is commonly used by athletes and bodybuilders as a sports supplement, with many reports and websites claiming muscle bulk growth in athletes through increased testosterone production and stimulation of human growth hormone release.
However, the scientific evidence does not support these claims. There is no solid valid scientific evidence for these effects, and the performance claims that are advertised are only supported by the conviction from athletes that γ-oryzanol is an excellent ergogen. Early research suggests that taking gamma oryzanol by mouth for 9 weeks while participating in resistance training does not improve muscular strength or jump power in well-trained male athletes.
One double-blind clinical trial with 30 healthy males (16 supplement group, 14 placebo group) at a dose of 600 mg/day for 9 weeks did find significant differences in bench press and leg curl outcomes, though no significant difference in anthropometric or skinfold measurements was reported. There is a limited number of studies available about the efficacy of gamma oryzanol supplementation with resistance exercise in humans. The conflicting results between trials reflect methodological differences (population, training status, and outcome measures), and the overall evidence base remains too limited and inconsistent to support efficacy claims.
The use of gamma oryzanol and phytosterols is gaining popularity among various athletic populations. These compounds are being consumed in the belief that they elicit anabolic effects ranging from increased testosterone production and release to stimulating human growth hormone release. However, published scientific studies suggest that these compounds are poorly absorbed; furthermore, animal studies indicate that when injected subcutaneously or intravenously, they induce antianabolic or catabolic activity.
Evidence strength: Weak. The majority of human evidence does not support ergogenic claims for gamma oryzanol. Scientific evidence does not strongly support claims that gamma oryzanol can improve muscle growth and athletic performance by influencing hormone levels.
5.5 Neuroprotection, Anxiety, and Cognitive Function
Gamma oryzanol's neuroprotective properties have been investigated primarily in preclinical (cell culture and animal) models. Emerging findings from various research groups have demonstrated that gamma oryzanol exerts neuroprotective effects and improves cognitive performance. Research showed that chronic oral administration of gamma oryzanol is able to prevent behavioral alterations and neuronal inflammation induced by lipopolysaccharide (LPS) in adult mice. Using a proteomic approach, mice chronically treated with gamma oryzanol showed increased expression of proteins associated with synaptic plasticity, mitochondrial energy metabolism, and neuroprotection.
Animal studies have also explored anxiolytic effects: previous evidence suggests that γ-oryzanol has anxiolytic effects on long-term stressed mice, and the mechanism may be related to its promotion of 5-hydroxyindoleacetic acid and norepinephrine levels in the brain. Anxiolytic-like effects of gamma oryzanol have been demonstrated in high-fat diet-exposed mice; the neurochemical and molecular mechanisms underlying this effect relate to monoaminergic dysfunction and inflammation.
Gamma oryzanol treatment was able to improve cognitive performance during the neuroinflammatory response in mice. Furthermore, phase II antioxidant enzymes such as heme oxygenase-1 (HO-1) and NADPH-dehydrogenase-quinone-1 (NQO1) were upregulated in the hippocampi of treated mice.
Evidence strength: Preclinical only. The neuroprotective and anxiolytic data are derived from in vitro cell culture and animal studies. No robust, peer-reviewed human clinical trials specifically examining cognitive or anxiety outcomes have been published as of 2024–2025. These findings are hypothesis-generating rather than confirmatory.
5.6 Thyroid Function
An early clinical observation, subsequently confirmed in a published study, revealed that gamma oryzanol affects thyroid-stimulating hormone (TSH). A single oral dose (300 mg) of gamma oryzanol extracted from rice bran oil produced a significant reduction in the elevated serum TSH levels in hypothyroid patients. Similarly, chronic treatment with gamma oryzanol resulted in decreased serum TSH levels in 6 of 8 patients. There was no change in the serum levels of thyroxine-iodine and triiodothyronine during the study. In addition, there was no difference in the serum TSH response to TRH in hypothyroid patients and normal subjects. These observations suggest that gamma oryzanol inhibits serum TSH levels in patients with primary hypothyroidism, possibly by a direct action at the hypothalamus rather than the pituitary.
Evidence strength: Limited; based on a small, older Japanese study. The finding has not been consistently replicated in rigorous controlled trials, but it constitutes an important safety consideration (see Section 8).
5.7 Eczema and Dermatological Applications
Early research suggests that bathing in bathwater containing gamma oryzanol each day for up to 6 months improves symptoms of eczema in children. Topical cosmetic formulations have historically incorporated gamma oryzanol as an antioxidant, sunscreen-synergist, and skin-conditioning agent.
Evidence strength: Very limited; based on a single early study. Topical use is primarily supported by the compound's in vitro antioxidant properties rather than replicated clinical trials.
5.8 Gastrointestinal and Anti-Ulcer Effects
Gamma oryzanol has a history of use in Japan for gastrointestinal complaints, including stomach upset and peptic ulcer symptoms. It has been approved in Japan for menopausal symptoms, mild anxiety, stomach upset, and high cholesterol. Early Japanese pharmacological studies reported antiulcerogenic actions, attributed to effects on mucosal protective mechanisms; however, large human clinical trials in this area remain sparse.
Evidence strength: Largely from early, small Japanese clinical studies with limited modern replication. Clinical trial data are often of poor methodology, making it difficult to support suggested clinical applications; however, rice bran oil and its components may have applications in high cholesterol, cancer, and dermatology.
5.9 Cancer
Rice bran oil and its isolated constituents, including gamma oryzanol, have been investigated for antiproliferative and antineoplastic activity, primarily in in vitro cell line studies and animal models. Reviews of the literature on rice bran oil and its constituents have been published in the context of animal studies and in vitro studies using various human cancer cell lines. Most studies report antineoplastic action; however, not all evidence is unequivocal.
Cellular antioxidant activity assays showed that supercritical extracts of rice bran rich in gamma oryzanol reduced the quantity of reactive oxygen species up to 50% in Caco-2 cells submitted to oxidative stress, and the extract was more effective in inhibiting colorectal cancer cell growth.
Evidence strength: In vitro and animal data only. No human clinical trial evidence is available to support gamma oryzanol as an anti-cancer agent in humans. This area remains speculative.
6. Body Systems and Health Areas Associated with Gamma Oryzanol
- Cardiovascular system: Lipid lowering (total cholesterol, LDL-C, triglycerides), anti-atherosclerotic via oxidative/inflammatory pathway modulation.
- Metabolic system: Glycemic control, insulin sensitivity, adipokine regulation, management of metabolic syndrome components.
- Endocrine system: Menopausal symptom relief, modulation of TSH, influence on hypothalamic-pituitary signaling.
- Nervous system: Preclinical anxiolytic effects, neuroprotection against neuroinflammation and oxidative stress, cognitive support in animal models.
- Gastrointestinal system: Anti-ulcer activity, cholesterol excretion through fecal pathway, emerging gut microbiota modulation.
- Skin and cosmetics: Antioxidant, UV-protection synergism, skin-conditioning in topical formulations.
- Immune and anti-inflammatory: NF-κB inhibition, reduction of CRP, IL-6, IFN-γ, TNF-α.
γ-Oryzanol has been reported to possess numerous beneficial properties including antioxidant, anti-inflammatory, anti-aging, cholesterol-lowering, and neuroprotective effects. All these properties suggest γ-oryzanol as a valuable multitarget ingredient for pharmaceutical and cosmetic formulations and for foods.
7. Dosage Forms and Dosages Reported in Studies
Gamma oryzanol has been studied in several dose ranges across different clinical applications. The following are dosages as reported in published sources:
- For lowering cholesterol, the usual dose of gamma oryzanol used in studies is 300 mg daily. In one study, 100 mg three times daily (300 mg total) was used.
- In a study of 20 dyslipidemic schizophrenic patients on neuroleptics, each patient was given 100 mg of gamma oryzanol three times daily for 16 weeks.
- Rice bran oil has been used in doses of up to 800 mg daily in clinical studies in high cholesterol. Purified gamma oryzanol has been used at a daily dose of 500 mg/day.
- A common dose of gamma oryzanol is 300 milligrams, which has been taken up to six months for hyperlipidemia (high cholesterol). This dose has also been used for hypothyroidism as a single dose.
- Another common dose is 100 milligrams of the proprietary preparation Hi-Z (Otsuka Pharmaceutical, Tokyo, Japan), which has been taken for skin conditions (up to four weeks) or hyperlipidemia (up to sixteen weeks).
- For bodybuilding, 500 milligrams daily has been used according to manufacturer's instructions for up to nine weeks. For menopausal symptoms or hyperlipidemia, 1.5 grams of a gamma oryzanol fine particle preparation (containing 300 mg gamma oryzanol) for up to eight weeks has been used.
- Human studies have typically used doses ranging from 100 mg to 600 mg daily. The Japanese prescription form for autonomic disorders uses doses around 10–30 mg three times daily.
- When taken by mouth, gamma oryzanol is possibly safe when used in doses up to 300 mg daily. It seems to be well-tolerated.
8. Safety Considerations and Notable Interactions
General Tolerability
No significant side effects have been produced in experimental and clinical studies. Clinical studies consistently report a favorable safety profile for γ-oryzanol, with minimal adverse effects and no major safety concerns to date.
Thyroid Function
The most clinically significant safety signal documented in human research concerns the thyroid axis. A single oral dose of 300 mg of gamma oryzanol produced a significant reduction in the elevated serum TSH levels in hypothyroid patients, and chronic treatment resulted in decreased serum TSH levels in 6 of 8 patients. Gamma oryzanol might lower thyroid function. It is advised not to use gamma oryzanol if you have thyroid problems. This effect was interpreted as a hypothalamic, rather than pituitary, action.
Pregnancy and Breastfeeding
There is not enough reliable information about the safety of taking gamma oryzanol if you are pregnant or breast-feeding. It is advised to stay on the safe side and avoid use in these populations.
Renal Function
Contraindications have not yet been identified; however, use of products containing phytic acid, a chemical constituent of rice seed, is not advised in patients with poor kidney function.
Potential Carcinogenicity Signal
An increase in bladder cancer has been associated with exposure to the sodium salt of phytic acid (a constituent co-occurring in rice bran), but not the potassium or magnesium salts; and an increase of lung cancer has been suggested for high-dose gamma oryzanol in some data. These signals come from isolated studies and have not been confirmed in controlled human research. Rice bran oil has not been shown to cause mutations or cancer in short-term animal studies.
Contamination History
Concerns regarding toxicity have historically been linked to an incident in the late 1960s in Japan when contaminated rice bran oil affected at least 1,800 people. Subsequent investigation established that this contamination event was due to polychlorinated biphenyls (PCBs), not gamma oryzanol itself, and this safety concern does not apply to properly processed gamma oryzanol preparations.
Long-Term Safety Data
The generalizability of current findings regarding safety is limited by small sample sizes and inconsistent dosing regimens. Large-scale, well-designed clinical trials are needed to validate its long-term safety.
Interactions
Gamma oryzanol may reduce thyroid-stimulating hormone (TSH) in patients with hypothyroidism. Although not well studied in humans, oryzanol combined with a high cholesterol diet may increase the risk of bleeding. The potential for interaction with cholesterol-lowering drug therapy has been identified given that gamma oryzanol itself inhibits cholesterol absorption and HMG-CoA reductase — additive effects on lipid lowering with statins or other lipid-lowering agents are theoretically possible but have not been extensively studied in controlled human trials.
References
Go back