Source Naturals Oil of Oregano is from wildcrafted true oregano (Origanum vulgare), an aromatic herb that is native to the Mediterranean region. Traditionally, oregano was used to support digestive, respiratory and joint health. Recent in vitro research indicates that carvacrol, an active constituent of oil of oregano, may provide support to the immune system. Source Naturals was created in 1982 to support each individual's potential to enjoy optimal health. Source Naturals' comprehensive Bio-Aligned Formulas help bring the power of alignment to your body. When formulating, we evaluate the underlying causes of system imbalances, and then provide targeted nutrition to interdependent body systems. Our line of more than 600 products also includes well-researched, single entity nutrients in their highest quality and most bioavailable forms.Source Naturals Oil of Oregano is the most potent on the market and is standardized to 70% carvacrol.