Sara Borrell studied pharmacy in Madrid and, following the Spanish Civil War, pursued postgraduate training in endocrinology in the United Kingdom, initially focusing on dairy products. Upon returning to Spain, she joined the Spanish National Research Council (CSIC). In 1950, she returned to Cambridge, where she worked at the Dunn Nutritional Laboratory on chromatography, particularly on the determination of adrenal corticosteroids and the chromatographic separation of 17-ketosteroids. In 1953, she continued her research at the renowned Worcester Foundation for Experimental Biology in Massachusetts with Drs. Gregory Pincus—a pioneer of the oral contraceptive pill—and Clark Hoagland, specializing in steroid hormones. Her early investigations centered on steroid metabolism in both humans and cats, the latter chosen for their similarity to humans in glucocorticoid metabolism. She later explored the interactions between adrenal cortex steroid hormones and adrenal medulla catecholamines. In the 1970s, as neuroendocrinology emerged, her research shifted toward understanding how brain monoaminergic systems regulate adrenal hormone secretion. Sara Borrell was among the pioneers in elucidating steroid metabolism, making a lasting contribution to the advancement of endocrinology and medical science.