"Natural progesterone was hard to come by. Extracting it from animal sources was difficult, time consuming and prohibitively expensive. Natural progesterone drug therapy required huge doses to be effective, and at a cost of anywhere from $80 to $1,000 per gram, only the richest patients could afford the treatment. The only customers for the drug turned out to be world-class race horse breeders, who used it to improve the fertility of their mares. Aside from the high cost, the drug had to be given as an injection, and the shots were painful and not well metabolized. Unless researchers could find a way to produce a highly effective synthetic oral dosage of the hormone, the treatment would remain impractical. In 1943 a chemist by the name of Russell Marker came up with the answer. As a professor at Penn State, Marker had discovered a way to extract progestprogesterone from plant material. Soon after, he was able to create synthetic estrogen from vegetation as well. His path-breaking process, which became known as the "Marker Degradation," remains the basis of synthetic hormone production today. Marker still needed to find a plant that could yield enough progesterone to make mass production possible. He traveled across America in search of the right source, but came up empty-handed. Unwilling to abandon his quest, he headed south to Mexico in search of a plant called cabeza de negro that he had read about by chance in a dusty old regional Texas botany book. His hunch was correct, and the giant tubers proved to be an excellent source for the cheap mass production of progesterone."