Mechanism of action of Sildigra is similar to the branded Viagra drug as both are loaded with the same chemical which is sildenafil citrate. Erectile dysfunction is the process which has many reactions involved in it. It starts in the brain and ends with the harder male organ. When your brain gets a signal saying that men is getting sexual stimulation, it responds with the signals that make the arteries to carry more and more blood to the male reproductive organ. As a result it attains hardness and it stays in that state for longer time span.