In the United States, the Food and Drug Administration (FDA) exerts strict control over the commercial distribution of a pharmaceutical product, including biopharmaceuticals. Approval can require several years of clinical trials, including trials with human volunteers. Even after the drug is released, it will still be monitored for performance and safety risks. The products of pharming are recombinant proteins or their metabolic products. Drugs made from recombinant proteins potentially have greater efficacy and fewer side effects than small organic molecules (which are often screened as potential drugs) because their action can be more precisely targeted toward the cause of a disease rather than treatment of symptoms. Recombinant proteins are most commonly produced using bacteria or yeast in a bioreactor, but pharming offers the advantage to the producer that it does not require expensive infrastructure, and production capacity can be quickly scaled to meet demand. It is estimated that the expense of producing a recombinant protein drug via pharming will be less than 70% of the current cost. One approach to this technology is the creation of a transgenic mammal that can produce the biopharmaceutical in its milk (or blood or urine). Once an animal is produced, typically using the pronuclear microinjection method, it becomes efficacious to use cloning technology to create additional offspring that carry the favorable modified genome.[1] The first such substance approved for therapeutic use was biosynthetic 'human' insulin made via recombinant DNA technology. Sometimes referred to as Biopharming, is a sub-sector.