As you may have noticed, Viagra and sildenafil citrate, generic Viagra pills, vary greatly in price. Fortunately, that is the main difference between the two medications. Generic Viagra is therapeutically equivalent to brand name Viagra. These medications contain the same active ingredients. Sildenafil citrate is so much cheaper because generic manufacturers are not forced to spend as much money testing or advertising their products. This savings is passed along to consumers who choose to take advantage of the lower prices.