By stopping the chemicals that let blood leave an erection
Thats why they're called "PDE-5 inhibitors"
How Erectile Dysfunction Medication Works
Getting an erection is a complicated chain of events. But at the core, erections are all about blood flow. Erectile dysfunction medication works by interfering with the chemical process that lets blood leave an erect penis. Erectile dysfunction meds like Viagra, Cialis, and Levitra are part of a family of drugs called PDE-5 inhibitors.
PDE-5: Your Erection “Off Switch”
When a man gets aroused, their brain releases chemicals that relax arteries and constrict veins in the penis. This lets more blood into the penis than flows out. The result is an erection. Erections would last forever—and bad things would happen—if your body didn’t restore normal blood flow to the penis. Phosphodiesterases enzymes (PDE-5) return the penis to normal by relaxing veins in the penis, essentially “turning off” the erection and letting blood flow out of the penis.
An erect penis contains up to 8x the normal amount of blood flow
In healthy men, erections and PDE-5 enzymes are in harmony. Erections last long enough for “satisfactory” sex, then go away so normal blood flow can resume. But when the PDE-5 balance is off, the result is either erectile dysfunction or priapism.
- Too much PDE-5 – Can cause soft erections or difficulty getting an erection
- Not enough PDE-5 – Can cause erections that last longer than 4 hours (priapism)
ED medications work by blocking PDE-5 from bringing your erection to an end. ED drugs like Cialis and Viagra tip the chemical balance in favor of your erection. That’s why doctors call ED drugs “phosphodiesterase inhibitors” (PDE-5 inhibitors for short).