Viagra (Sildenafil)

Viagra, the brand name for Sildenafil Citrate, is a PDE5 (phosphodiesterase type 5) inhibitor used to treat erectile dysfunction (ED) by increasing blood flow to the penis during sexual stimulation. Originally developed for cardiovascular use, it was later repurposed when clinical trials revealed a strong impact on erection quality and duration.

Viagra works by enhancing the nitric oxide–cGMP pathway, leading to vasodilation (widening of blood vessels) in penile tissue. It has become one of the most well-known and effective solutions for ED and is also used recreationally for performance enhancement or in conjunction with other anabolic compounds that may affect libido or sexual function.