Long-time readers know that my “go-to” sources for natural medicines (herbs, vitamins, and supplements) are ConsumerLab.com and Natural Medicines(TM). ConsumerLab has posted about coronavirus and quercetin:
Quercetin and its major metabolites, such as quercetin 3-beta-O-d-glucoside (Q3G, also called isoquercetin), have been found in laboratory studies to inhibit a wide variety of viruses, including severe acute respiratory syndrome coronavirus (SARS-CoV), which is related to COVID-19.
For example, one of these studies showed that when mice were injected with high doses of Q3G before being infected with a lethal dose of the Ebola virus, they survived Ebola infection, while none of the mice that did not receive Q3G survived.
According to preliminary research, quercetin appears to work by preventing viruses from entering cells, thereby reducing “viral load.”
A clinical trial that will investigate the use of oral quercetin in patients with COVID-19 has been planned, or may already be underway, in China.
Details about the exact form (quercetin or 3-beta-O-d-glucoside) and dose of the formula (produced by the Swiss drug manufacturer, Quercegen Pharmaceuticals) do not appear to have been made public, but in a February 2020 interview posted online by the Canadian Broadcasting Company (CBC News), researcher Michel Chrétien stated he hopes to have preliminary results in the upcoming months.
However, he cautioned that he does not want to give “false hope” about the potential benefits of quercetin until more research is conducted.
Until more is known, it’s not clear if taking isoquercetin or quercetin supplements can help prevent or treat COVID-19 or what dosage would be effective.
In small clinical trials investigating the effects of quercetin for other uses, such as for seasonal allergies, prostatitis or rheumatoid arthritis, quercetin (at doses ranging from 50 mg to 1,000 mg daily) is generally well-tolerated, although side effects such as nausea and headache can occur, particularly at doses of 500 mg and higher.
Quercetin is naturally found in food such as capers, onions, apples, and certain berries, and people get about 25 mg of quercetin daily from their diets.
Be aware that quercetin may interact with certain medications, including some statin medications like rosuvastatin (Crestor), atorvastatin (Lipitor) and pravastatin (Pravachol), and others.
ConsumerLab’s tests of popular quercetin supplements have found that some products contain much less quercetin than listed on the label.
Based on its tests and review, ConsumerLab has published its Top Picks in its Quercetin Supplements Review, which contains additional information about using quercetin, its benefits, dosing, and potential side effects.
Of course, the most important thing you can do to avoid infection with coronavirus is to prevent exposure by following the latest recommendations of the CDC and World Health Organization and take steps to stay healthy, including getting adequate sleep, keeping up with your daily exercise, and eating a healthy nutritious diet.
© Copyright WLL, INC. 2020. This blog provides a wide variety of general health information only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment from your regular physician. If you are concerned about your health, take what you learn from this blog and meet with your personal doctor to discuss your concerns.