Tadalafil is > 10,000-fold more potent for PDE5 than for PDE1, PDE2, and PDE4, enzymes which are found in the heart, brain, blood vessels, liver, and other organs.
Tadalafiil on PDE5 suhtes üle 10000 korra tugevama toimega kui südames, peaajus, veresoontes, maksas ja teistes elundites leiduvatele ensüümidele PDE1, PDE2 ja PDE4.