Garlic

Warnings
Some herbal and diet supplement products have been found to contain possibly harmful impurities and additives. Side effects, although uncommon have been reported, such as stomach upsets, gas, heartburn and rashes. 

Garlic should be used with caution after surgery or serious injury, since its anti-clotting properties, it may increase the chance of bleeding problems. Liquid preparations of this product may contain sugar and/or alcohol. Caution is advised if you have diabetes, alcohol dependence or liver disease.

Medical Uses
Antibacterial effects: Crushing the bulbs to release the juices and oils to the air forms a compound known as diallyl disulfide. Thus, breathing in the fumes in the lungs and throat or skin exposed to it can kill the bacteria on the surface, therefore, an aid against flu’s and virus.

Reduce blood clotting and blood pressure (cardiovascular disease): Eating the prepared bulb raw or pickled is best or oil extracts in concentrated form for enhanced effectiveness.

Stomach cancer prevention properties: Regularly eating garlic is beneficial in preventing stomach cancers. 
Stimulates the immune system stimulates the activity of macrophages and the activity of helper T cells. 
Reduction of hardening of the arteries (atherosclerosis), high cholesterol (blood lipids), and circulation problems.