Description:

Viagra 50 mg contains Sildenafil Citrate, a well-known phosphodiesterase type 5 (PDE5) inhibitor used in the treatment of erectile dysfunction (ED) in men. It helps men with ED achieve and maintain an erection sufficient for sexual activity by improving blood flow to the penis.
Sildenafil is effective only with sexual stimulation and typically begins working within 30 to 60 minutes, with effects lasting up to 4–6 hours.

Sildenafil inhibits the PDE5 enzyme, which is responsible for the breakdown of cyclic guanosine monophosphate (cGMP). During sexual stimulation, nitric oxide (NO) is released, which increases cGMP levels in the corpus cavernosum, relaxing smooth muscles and enhancing blood flow. By preventing the breakdown of cGMP, Sildenafil prolongs the erection.