Erectile dysfunction tablets are typically safe to use both in the short term and long term. The results of a study looking at men using sildenafil over the course of four years suggest that it’s safe and effective when used over a prolonged period of time. Likewise, another study involving 1173 men with ED concluded that tadalafil was “safe and well tolerated” when used for the duration of the study, which lasted for two years. In general, if you find yourself taking sildenafil - or any other ED treatment - for a prolonged period of time, it’s worth looking at the underlying causes (with the help of your doctor).