Prices for pharmaceutical products over the last 10 years have skyrocketed, increasing far more rapidly than the general cost of living. This article argues there should be greater competition for the production of follow-on drugs through the strengthening of the double patenting prohibition: preventing extending exclusive rights beyond the original patent term by dressing up part of that invention as a new one. This prohibition against the same party holding two patents covering the same composition announced by the Supreme Court in the 1800’s has been weakened by lower federal courts to (1) only considering the claims and not the rest of the specification in determining if the same invention is being claimed by the inventor in two patents and (2) only applying the prohibition when the earlier patent did not satisfy the technical meaning of “prior art” within §102 of the Patent Act. The rulings weakening the double patenting doctrine have disregarded that the “invention” of a genus patent is not determined only by the claims, but also by the embodiments disclosed in the specification, and under Supreme Court and Federal Circuit precedent it must be presumed that the party with a genus patent has invented the full scope of the genus. These weakening rulings have also disregarded that the double patenting doctrine arises from §101 of the patent statutes, rather than §§102 and 103, which the Federal Circuit models it double patenting test on, often incorrectly concluding there is no double patenting. §§102 and 103 serve different purposes than §101. This article argues that when the same inventor holds a genus patent for a pharmaceutical product, it should be estopped from obtaining a patent on a species within the scope of the genus, whether or not the genus patent constitutes prior art. Applying this strengthened double patenting doctrine would increase competition for the development of follow-on pharmaceutical products.