You can theoretically stay on enclomiphene 50 mg long-term (for years) under close medical supervision, but a 50 mg daily dose is unusually high and typically reserved for short-term correction or severe non-responsiveness. Because enclomiphene works by blocking estrogen receptors to stimulate your body's natural testosterone production, your hormone levels will drop back to your baseline within about a month if you stop taking it.
Get more info here: https://www.australiarxmeds.com/product/enclomisign-50-mg/