When the blood vessel muscle cells relax, this expands the vessel and increases blood flow; this effect is referred to as vasodilation. That means seven out of 10 people who take these drugs as prescribed will have more frequent or longer-lasting erections. Tadalafil is also used to treat men who have signs and symptoms of benign prostatic hyperplasia BPH. Both medications are generic now and can be found at discounted rates, making them more accessible to the public than ever before. Viagra is always taken as needed, usually about an hour before sex. · Descriptions. Tadalafil is used to treat men who have erectile dysfunction (also called sexual impotence). Tadalafil belongs to a group of medicines called . Tadalafil is used to treat male sexual function problems (impotence or erectile dysfunction-ED). Your doctor will determine which is the best way for you to take tadalafil. Follow your doctor. So, to answer that, let’s examine these differences in a little more detail: 1. They Look Different. Cialis tablets are typically yellow, oval-shaped, and film-coated. They come in mg, 5mg, 10mg, or 20mg doses. Tadalafil, meanwhile, might look similar — but it’s also available in different shapes and colours.