Although Pfizer enjoys the patent right of sildenafil in most countries in the world, it has lost this privilege in some countries, including Bolivia, Colombia, Peru in South America and Britain in Europe. In 2004, China people and China National Intellectual Property Administration also rejected Pfizer's patent application for sildenafil in the treatment of erectile dysfunction. On June 2, 2006, Beijing No.1 Intermediate People's Court ruled that Pfizer won the case.
Other sildenafil preparations
In addition to legal Viagra, there are some health care products or drugs containing sildenafil, but this situation is illegal.