Sildenafil citrate in Vigora 100 mg works by increasing blood flow to the penis during sexual stimulation, which helps achieve and maintain an erection sufficient for sexual activity. This improvement in erectile function can address impotency issues and restore sexual confidence. By using Vigora 100 mg as directed, individuals with impotency can experience improved erectile function, leading to successful and satisfying sexual encounters. It's important to note that sexual arousal is still required for the medication to be effective.