Garlic is a stimulant for the immune system – it is the closest thing to a herbal wonder drug for treating infections. This is because garlic is anti-bacterial, anti-viral, anti-fungal and anti-parasitic. Garlic is rich in sulphur which is essential for healthy skin and hair, and garlic also contains bioflavonoid compounds such as quercetin which retard inflammatory reactions. Quercetin stabilises mast cells (which contain histamine) and inactivates many inflammatory enzymes, which makes garlic a useful anti-allergy tool. Garlic also works to improve circulation. It contains a number of anti-coagulant compounds and has a blood-thinning effect as well as being vasodilatory.