We can extrapolate the safety from Clomiphene studies, which have been conducted for 60+ years. Enclomiphene is the isomer (with zuclomiphene being the other) that has the main effect you see from enclomiphene. Zuclomiphene is an estrogen agonist and actually decreases testosterone and LH/FSH. Of note, every study done on enclomiphene has showed it's efficacy and safety (especially in comparison to clomiphene)