Quercetin belongs to a class of water-soluble plant pigments called flavonoids. Quercetin can be found in onions, apples, green tea, and black tea. Smaller amounts are found in leafy green vegetables and beans.

What it does

  1. Anti-inflammatory: Quercetin inhibits the release of histamine by influencing two enzymes involved in its release from mast cells. It also decreases prostaglandins which are the chemicals of inflammation.
  2. Pain Reliever: Compared to aspirin, quercetin has been found to relieve pain and stiffness naturally, whilst fortifying connective tissue. Unlike many glucocorticoids and drugs, quercetin does not cause damage to the gastrointestinal wall.
  3. Allergies: Quercetin inhibits the release of histamine reducing the production of inflammatory prostaglandins involved in the allergic response.
  4. Anti-Viral: Quercetin works by interfering with enzymes that breakdown the protective protein coat of a virus, preventing replication and infection. Quercetin has been shown to stunt the growth of the Herpes virus.
  5. Collagen Strengthener: As a bioflavonoid, quercetin is helpful in supporting collagen structures and preventing collagen destruction.
  6. Antioxidant: Quercetin scavenges oxygen radicals and inhibits the harmful effect of oxidation of LDL cholesterol. It is also protective to Vitamin C in the body.

Potential Uses

Hayfever Asthma Crohns disease
Ulcerative colitis Gout Inflammation
Bursitis Migraine Sciatica and back pain
Sinusitis Stomach ulcers


If you take the blood pressure drug felodipine it is best to avoid using quercetin supplements.

Generally, there are no side effects or contra-indications from using quercetin.

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