The rationale for use of glandular tissue concentrates is based on a simple and universal concept “like heals like”. If an organ or gland is functioning poorly, consumption of healthy cells or concentrates can support the function of that organ. The active factors lie in the water-soluble fraction of the tissues, especially in the various peptides, polypeptides, proteins and enzymes. Even though much of this material, when taken orally, is denatured and hydrolyzed by digestion, varying amounts survive gastrointestinal passage and are taken up intact. Many of these materials are so potent that even in microgram quantities, they can have a profound physiological effect on their target organs. In addition, many of these proteinaceous materials exert their effect primarily on the organ which produces them or on a closely related tissue.