Citrus bioflavonoids
Synopsis
Citrus bioflavonoids are a group of plant-derived polyphenolic compounds naturally found in citrus fruits such as oranges, lemons, grapefruits, limes, and tangerines. They are concentrated in the peels, membranes, and white inner rind (albedo) of the fruit and are often extracted for use in dietary supplements. Common citrus bioflavonoids include hesperidin, naringin, rutin, quercetin, diosmin, and eriocitrin. These compounds are not technically vitamins, but they are sometimes referred to as vitamin P, a term once used to describe their vascular-supportive properties.
Bioflavonoids act primarily as antioxidants, helping to scavenge free radicals, reduce oxidative stress, and stabilize vitamin C. They also exhibit anti-inflammatory, antiviral, anti-allergic, and capillary-protective effects. Their ability to strengthen capillary walls makes them particularly useful in treating conditions involving venous insufficiency, hemorrhoids, varicose veins, and bruising. Citrus bioflavonoids are also known to improve circulation, reduce edema, and support cardiovascular health by enhancing endothelial function and reducing platelet aggregation.
In addition to vascular benefits, some citrus bioflavonoids—particularly naringin and hesperidin—have demonstrated antiviral and lipid-lowering effects, as well as potential roles in modulating blood glucose, supporting liver detoxification, and improving skin health. They are commonly paired with vitamin C in supplements to enhance absorption, prolong activity, and deliver synergistic immune support.
Citrus bioflavonoids are generally safe and well tolerated, though in very high doses they may interact with certain medications, especially those metabolized by the cytochrome P450 enzyme system.
Historical Use
Though the term “bioflavonoid” and the isolation of individual compounds are modern developments, the medicinal use of citrus fruits has ancient roots. Citrus fruits were historically used in Chinese, Indian, Persian, and Greco-Arabic medicine for their ability to stimulate digestion, purify the blood, cool internal heat, and treat fevers and infections.
The white pith and peel of citrus fruits—where bioflavonoids are most concentrated—were often included in traditional preparations such as preserved peels, marmalades, decoctions, and tonics. In Ayurveda, citrus peels (especially from lime and orange) were used to balance vata and kapha doshas, aid digestion, and clear respiratory blockages. In Traditional Chinese Medicine, citrus peel (chen pi) was used to regulate qi, transform phlegm, and support spleen and stomach function.
Scientific recognition of citrus bioflavonoids began in the 1930s, when Nobel Prize–winning scientist Albert Szent-Györgyi, while researching vitamin C, discovered that extracts from citrus peels improved capillary strength and reduced bruising more effectively than isolated vitamin C alone. This led to the early classification of bioflavonoids as “vitamin P” (P for permeability).
Today, citrus bioflavonoids are widely used in cardiovascular, immune, and skin health formulas, as well as in anti-aging and allergy support supplements. They represent a perfect example of how modern science has validated and enhanced the traditional use of whole plant materials—particularly citrus peels—for systemic and vascular wellness.
Body Systems
Arteries (Traditional)
Circulatory System (Science)
Immune System (Science)
Skin (Science)
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