Garlic (Allium sativum; Liliaceae) can be used both as fresh cloves or aged extracts and powders. Garlic ranks high among health-enhancing herbs, largely due to its antioxidant sulfur compounds. The health benefits may differ according to whether garlic is fresh or aged, but both are good for strengthening the body's immune system as well as aiding in healing diseases and ailments. Garlic chemistry is complex, and a number of compounds are produced by the aging process. Garlic's constituents include antioxidant phytochemicals, such as organosulfur compounds; flavonoids, such as allixin, which are capable of scavenging free radicals; trace elements, such as germanium (normalizer and immunostimulant) and selenium; volatile oil, which contains sulfur compounds; amino acids; and other bioactive compounds.

Aged garlic is produced by extracting and aging organic fresh garlic at room temperature for 20 months. By combining this extraction/aging process, the antioxidant levels in the extract can become greater than those in fresh cloves. The process also converts garlic's more unstable substances, generally not available to the body, to more stable, bioavailable, and health-promoting substances. Aged garlic contains stable water-soluble sulfur substances, including S-allylmercaptocysteine and S-allyl cysteine, which are powerful antioxidants and have high bioavailability and increased absorption into the blood. The water-soluble sulfur compounds may be largely responsible for the health benefits of aged garlic.