When it is cut, chemical reactions occur that create dozens of new compounds. Controversy whether garlic's medicinal compounds are destroyed through processing or best to use fresh garlic. Changes in heartbeat, constipation, diarrhea, flatulence, heavier menstrual flow, nausea, and skin rash have been reported rarely. Allergic contact dermititis occurs in some species of feverfew. Other effects include constipation, dizziness, dry mouth, phototoxicity, and sleep disturbances.
Prolonged administration leads to immune-system overstimulation and eventual suppression.
Garlic None if taken with recommended use. If used excessively, then heartburn, Flatulence, GI problems, reduces clotting time of blood. Ginkgo Biloba Rare but GI discomfort, headache, and allergic skin reactions, prolongation of bleeding time possible. St. John's Wort Avoid in severe depression. Garlic Monitor patients on antiplatelet drugs and warfarin.