비아그라의 기본 원리

Viagra can be a brand-name Model on the generic drug sildenafil. It’s a phosphodiesterase type five (PDE5) inhibitor. PDE5 is definitely an enzyme that regulates specific chemical substances as part of your blood, but thanks to its effect on the human body, it will make it harder for you to get and continue to keep an erection.a affliction called