Methyl p-hydroxyphenyllactate, a natural product isolated and purified from the herbs of Crepis crocea., can suppress the cellular proliferation of estrogen-sensitive MCF-7 breast cancer cells in vitro and to suppress the growth of rat uteri in vivo, high affinity of MeHPLA for the type II estrogen binding site (EBS) suggests that this interaction is responsible for the observed suppression of cell growth.