Tags: Drug.
Equilin is an estrogen from horses with the chemical name 3-hydroxyestra-1357-tetraen-17-one. Equilin is one of the estrogens present in the mixture of estrogens isolated from horse urine and marketed as Premarin. Premarin became the most commonly used form of estrogen for hormone replacement therapy in the United States of America. Estrone is the major estrogen in Premarin (about 50%) and equilin is present as about 25% of the total.
