Tadalafil, sold under the brand name Cialis among others, is a medication used to treat erectile dysfunction, benign prostatic hyperplasia, and pulmonary arterial hypertension. It is a tablet taken by mouth. Onset is typically within half an hour and the duration is up to 36 hours. This increase in blood flow raised the interest of bodybuilders: if Cialis is so great at increase blood flow, could it benefit the muscle as well? This is where the idea of Cialis for bodybuilding was born. So while Cialis won’t be helping you get massive gains, more than a few bodybuilders have caught on to the additional benefits that Tadalafil can provide; particularly when it comes to using it pre-workout.