Sildenafil also reduced certain molecular abnormalities associated with AD in cultured nerve cells derived from AD patients. It depends on the platform and insurance provider. Many men want to know how to get prescription ED pills without a doctor or other medical professional. This is in contrast to the earlier findings. Cialis Daily tadalafil : This low-dose Cialis works by increasing blood flow to the penis over time, making it easier to have an erection when aroused.Cialis Viagra; Main ingredient: tadalafil: sildenafil: How long it takes to work: around 30 minutes: around 30 minutes: How long it lasts: –36 hours: 4–12 hours: When to take it. Viagra takes around 30 minutes to become effective and lasts about 4 hours. Cialis lasts much longer — up to 36 hours in some cases. Stendra can start doing its thing in as little as 15 minutes. In addition to the already large savings offered by Canada Pharmacy from time to time we offer discount codes that can be used at checkout to save even more. Discounts range from $5 off to sometimes even 20% or more off! Cialis: Brand/Generic: $ – $ – 5 – 10 – 20 mg: View Product: Advair Diskus Viagra Cialis Propecia.