Selective estrogen receptor modulator (SERM) that displays selectivity for ERα over ERβ (Ki values are 0.09 and 11.31 nM respectively) and no cross-reactivity with mineralocorticoid, glucocorticoid, androgen and progesterone receptors. Acts as an agonist in the bone and antagonist in reproductive tissue. Suppresses estrogen-stimulated proliferation of ER-positive human breast cancer MCF-7 and T47D cells.