Mechanism of Action (MOA)

MOA for the treatment of ED

Male lower urinary tract and penis


Impact of nitric oxide and cyclic guanosine monophosphate (cGMP) on smooth muscle relaxation in the corpus cavernosum1

  • Penile erection during sexual stimulation is mediated by the release of nitric oxide, which stimulates the synthesis of cGMP in smooth muscle cells
  • cGMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum

CIALIS enhances erectile function by increasing cGMP concentration through phosphodiesterase 5 (PDE5) inhibition1

PDE5 in the prostate and bladder1


The mechanism for reducing BPH symptoms has not been established1

  • The effect of PDE5 inhibition on cGMP concentration in the corpus cavernosum and pulmonary arteries is also observed in the smooth muscle of the prostate and bladder and in their vascular supply1


  1. Cialis [package insert]. Indianapolis, IN: Eli Lilly and Company; 2017.