Ulobetasol propionate, also known as halobetasol propionate, is a synthetic glucocorticoid corticosteroid and a corticosteroid ester. Ulobetasol propionate, also known as halobetasol propionate, is a synthetic glucocorticoid corticosteroid and a corticosteroid ester. It was patented in 1975 and approved for medical use in 1991.