I’ve been taking Quercetin for years, long before Covid, as it’s been recommended by many functional MDs.



Quercetin belongs to a group of plant pigments called flavonoids that give many fruits, flowers, and vegetables their colors.

Flavonoids, such as quercetin, are antioxidants. They scavenge particles in the body known as free radicals which damage cell membranes, tamper with DNA, and even cause cell death. Antioxidants can neutralize free radicals. They may reduce or even help prevent some of the damage free radicals cause. In test tubes, quercetin has strong antioxidant properties. But researchers are not sure whether taking quercetin (and many other antioxidants) has the same effects inside the body.

Quercetin may help protect against heart disease and cancer. Quercetin can also help stabilize the cells that release histamine in the body and thereby have an anti-inflammatory and antihistamine effect.

An NIH study from 2018:

Restoring Effects of Natural Anti-Oxidant Quercetin on Cellular Senescent Human Dermal Fibroblasts



The oxidative damage initiated by reactive oxygen species (ROS) is a major contributor to the functional decline and disability that characterizes aging. The anti-oxidant flavonoid, quercetin, is a plant polyphenol that may be beneficial for retarding the aging process. We examined the restoring properties of quercetin on human dermal fibroblasts (HDFs). Quercetin directly reduced either intracellular or extracellular ROS levels in aged HDFs. To find the aging-related target genes by quercetin, microarray analysis was performed and two up-regulated genes LPL and KCNE2 were identified. Silencing LPL increased the expression levels of senescence proteins such as p16INK4A and p53 and silencing KCNE2 reversed gene expressions of EGR1 and p-ERK in quercetin-treated aged HDFs. Silencing of LPL and KCNE2 decreased the expression levels of anti-oxidant enzymes such as superoxide dismutase and catalase. Also, the mitochondrial dysfunction in aged HDFs was ameliorated by quercetin treatment. Taken together, these results suggest that quercetin has restoring effect on the cellular senescence by down-regulation of senescence activities and up-regulation of the gene expressions of anti-oxidant enzymes in aged HDFs.

Keywords: Aged HDFs; KCNE2; LPL; Mitochondrial Membrane Potential; Quercetin; Restoring Effect.