Leek is a product that warms and tonifies yang, and contains a certain amount of zinc, which can warm and tonify liver and kidney. Therefore, it is called "Yangyangcao" in Pharmacopoeia, comparable to the current "Viagra". In addition, leek contains volatile essential oil and sulfur-containing compounds, which can promote appetite and reduce blood lipid, and has certain curative effect on hypertension, coronary heart disease and hyperlipidemia. Sulfur compounds also have certain bactericidal and anti-inflammatory effects. Leek contains more dietary fiber, which can promote gastrointestinal peristalsis and effectively prevent habitual constipation and intestinal cancer. These dietary fibers can also wrap hair, gravel, metal chips and even needles in the digestive tract, and are excreted with feces, which is called "intestinal grass". At the same time, leek also has the effects of warming the middle warmer, promoting qi circulation, promoting blood circulation and detoxifying, keeping warm and invigorating the stomach.

Leek yellow is a kind of leek that is isolated from light and grows completely in the dark. Because there is no sunlight supply, photosynthesis cannot be produced. When chlorophyll is synthesized, the grown leek will turn yellow, which is called "leek yellow".