How does Malegra 100 work Malegra 100 uses the active ingredient Sildenafil, which is the same active ingredient found in Viagra. Sildenafil works by inhibiting the enzyme PDE5, which results in increased levels of cGMP in the corpus cavernosum of the penis. This increased level of cGMP leads to smooth muscle relaxation and increased blood flow to the corpus cavernosum, resulting in an...