Quercetin is one of the most common flavonoids present in abundance in many plants. It is currently being studies for many recently discovered benefits. Several of those benefits being lower blood pressure, inflammation and allergy relief.

Quercetin and Covid

Two quercetin studies from the last several months have released positive early data about their findings. One study was conducts at Institute of Nanotechnology of the Cnr (Consiglio Nazionale delle Ricerche). They found  quercetin acts as a specific inhibitor for the virus responsible for Covid-19. Their data showed a destabilizing effect on 3CLpro. This is one of the key proteins for virus replication. Quercetin reduces its enzymatic activity. By interfering with the replication of the virus and reducing cell adhesion to the host, it would appear to have antiviral properties.

A second quercetin study is ungoing in Saudi Arabia. Final results have not yet been released. The current conclusion to this study is currently worded as-

“The dreadful pandemic caused by SARS-CoV2 led to extremely high morbidity and mortality worldwide. There is no specific therapy and only supportive treatment to rescue patients’ life is the only available option. A novel Quadriple therapy consisting of Zinc, Quercetin, Bromelain and Vitamin C shows a promising positive therapeutic effect. This mini review is the basis of our running clinical controlled trial and results will be available (soon).”

During this Coronavirus pandemic quercetin has returned to the attention of many researchers as it may be effective in prohibiting replicatioin of the virus

This molecule can be associated with other substances indisputably essential to the immune system such as vitamin Czinc and vitamin D. Not surprisingly, the combination of different substances has made this new supplement performant and unique in its composition.


The association with vitamin C would seem to increase the bioavailability of Quercetin, interrupting the entry, replication and enzymatic activity of the virus and at the same time supporting and strengthening the immune response. The combined administration of Quercetin and Vitamin C is an experimental strategy for the prevention and treatment of various respiratory viruses.


Also in this case we are talking about the synergy of nutraceuticals as Zinc is able to break down inflammation and reduce the link between the virus and its receptor; moreover, it reduces viral replication. But to do this, Zinc needs ionophores that allow greater penetration into the cells: Quercetin is just an ionophore of Zinc.
Therefore this association allows the Zinc to enhance its antiviral action. Furthermore, other studies show that Quercetin finds complementarity with Bromelain, as it strengthens the anti-inflammatory activity by increasing the production of prostaglandins. Taken together, they are therefore an indispensable resource for supporting the immune system.


It is now known that vitamin D is very useful in the prevention and treatment of infections of the upper respiratory tract, as well as in the traditional flu. We cannot say that it has a specific and direct action on the virus, but we know that it is able to support the immune system and therefore make it more efficient against the virus. In addition, it would appear that Quercetin is able to activate the vitamin D receptor, which is why they are associated.

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