A garlic allergy involves an immune response to the proteins in garlic, while an intolerance involves the body having difficulty digesting certain substances, such as fructans. An allergy can cause serious reactions, while an intolerance mainly causes digestive problems. Proper diagnosis and avoidance of garlic can improve quality of life.

Raw garlic contains unstable allicin, which acts quickly but can irritate the stomach. Aged (black) garlic contains stable S-allyl cysteine (SAC) with stronger and longer-lasting effects – from heart and brain protection to better digestibility. It is also suitable for sensitive people.