No fillers, binders or additives | High-dose supplement | Third-party tested and certified free from contaminants | Produced in the UK to GMP standards | Vegan | Free from Gluten, Dairy and other allergens | Clean Supplement Quercetin is one of a group of vitamins collectively known as flavonoids, also sometimes called Vitamin P. For fruit and flowers, quercetin is their natural defence against insects, bacteria and mould. Quercetin contributes to the scent and colour of flowers, and adds its pigment to the colour of various orange and red fruits and vegetables. One way to identify the strength and quality of a quercetin supplement is by comparing the intensity of its yellow colour with alternatives. Quercetin, in its natural form in fruits, is not well absorbed by humans. This means we only take in a small amount of what we eat. In many fruits, it tends to be concentrated in the peel. For example, it's more concentrated in orange zest than inside the fruit. Who can benefit from extra Quercetin? People who suffer from frequent allergies may find that extra quercetin also helps them reduce the heavy tiredness that comes afterwards. Quercetin also helps to reduce the fatigue and tiredness that comes from intense exercise, and it also helps athletes by reducing the oxidative stress that inflicts damage on body cells after exercise. Why is our Quercetin so good? Our capsules contain just one ingredient: pure quercetin, from the flowers of the Japanese Pagoda Tree (sophora japonica) refined to 98% purity. This makes it one of the purest and most potent supplements on the market. The capsule contains no fillers, binders or other additives at all.