Determining the earliest time within 30 minutes to erectogenic effect after tadalafil 10 and 20mg: A multicenter, randomized, double—blind, placebo controlled, at home study. Androgens and penile erection: evidence for a direct relationship between free testosterone and cavernous vasodilation in men with erectile dysfunction. What should I talk to my doctor about when considering if Cialis is right for me? In the same way, both sexual desire and erectile function are responsive to testosterone and lack of sexual activity decreases T levels Ahn et al Clin Endocrinol Oxf ;— Role of phosphodiesterase and protein kinase G on nitric oxide-induced inhibition of prolactin release from the rat anterior pituitary. Age itself is an important risk factor for vascular disease and ED, and thereby endothelial dysfunction.Patients and methods. A prospective, single-blind, randomised study comparing the safety and efficacy of 5-mg tadalafil continuous daily dosing for 3 months compared with . Patients with BPH/LUTS-ED were treated by the urologist with 5 mg/day of tadalafil (Cialis ®, Eli Lilly Nederland B.V.). Neuropsychological assessment and blood . Was this helpful? How does Cialis work? Cialis works by increasing blood flow to the penis to help a person get and maintain an erection. It also blocks the PDE5 .