The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Avoid if allergic or sensitive to rice, red yeast, its parts, or members of the yeast family (Monascaceae).
Eye inflammation, hives, itching, nose inflammation, severe allergic reactions, shortness of breath, sneezing, and swelling under the skin have been reported with red yeast rice (RYR) exposure.
Side Effects and Warnings
There is a lack of data on side effects associated with red yeast rice extract (RYRE). In general, side effects and interactions for RYRE may be similar to those of low-dose "statin" drugs, since monacolin K is the same chemical compound as lovastatin. Side effect frequency appears to be low with moderate consumption. Long-term safety data are lacking.
RYR may cause anorexia, back pain, bloating, colon inflammation, constipation, diarrhea, erectile dysfunction, fatigue, flu, hair loss, indigestion, loose stools, stomach inflammation, stomachache, and upset stomach.
Mycotoxin citrinin, a compound made by Monascus species, may pose a health threat. High doses have been found to be harmful in animal research. There is no established limit in humans, and caution should be used when consuming products containing citrinin.
Red yeast rice (RYR) is likely safe when used as a condiment in food.
RYR is possibly safe when taken by mouth to lower cholesterol in doses of up to 2.4 grams daily for up to 12 weeks.
Use cautiously in doses higher than 2.4 grams daily for longer than 12 weeks.
Use cautiously in people who have skin disorders. Rash has been reported with RYR use.
Use cautiously in people who have abnormal liver function tests or liver disorders, or those using alcohol or agents that may be toxic to the liver. RYR may affect liver function.
Use cautiously in people who have kidney problems. RYR may be harmful to the kidneys.
Use cautiously in people who have stomach problems. RYR may worsen symptoms such as gas, heartburn, inflammatory bowel disease, and nausea.
Use cautiously in people who tend to have dizziness. RYR may cause dizziness.
Use cautiously in people who have low levels of coenzyme Q10 (CoQ10). RYR may further decrease CoQ10 levels.
Use cautiously in people who have headaches. RYR may cause headaches.
Use cautiously in people who have musculoskeletal disorders or those taking cyclosporine, cytochrome P450-3A blocking agents, or macrolide antibiotics. RYR may increase the risk of muscle disease, muscle fiber breakdown, and muscle pain.
RYR may affect blood sugar levels. Caution is advised in people with diabetes or low blood sugar and in those taking drugs, herbs, or supplements that affect blood sugar. Blood sugar levels may need to be monitored by a qualified healthcare professional, including a pharmacist, and medication adjustments may be necessary.
Use cautiously in people who have low iron levels. RYR may affect hemoglobin.
Use cautiously in people who have a weakened immune system or those taking agents that may weaken the immune system. Use cautiously in people who are undergoing surgery or an organ transplant. RYR may weaken the immune system.
Use cautiously in people who have nerve damage. RYR may increase the risk of nerve damage.
RYR may affect the risk of bleeding. Caution is advised in people with bleeding disorders or those taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.
RYR may cause low blood pressure. Caution is advised in people taking drugs or herbs and supplements that lower blood pressure.
Use cautiously in people taking cardiac glycosides. RYR may interact with these agents.
Use cautiously in people who have thyroid disorders, or those taking thyroid hormones or medications. RYR may reduce the effectiveness of these agents and may affect thyroid hormone levels.
Use cautiously in people taking ranitidine (Zantac®). RYRE may increase the risk of kidney damage.
Avoid using RYR in children and adolescents under the age of 18, or in pregnant or breastfeeding women. There is a lack of safety information on the use of RYR in these populations.
Avoid if allergic or sensitive to rice, red yeast, its parts, or related members of the yeast family (Monascaceae).
Pregnancy and Breastfeeding
There is a lack of scientific evidence on the use of RYR during pregnancy or breastfeeding.
This evidence-based monograph was prepared by The Natural Standard Research Collaboration