When you and a clinician are choosing a dose, you should go for the lowest dose that you think will work. A starting dose of 50mg is usually prescribed if you have not previously used this medication or if you are taking other medications, which may cause potential side effects. This helps blood flow into your penis more easily, and helps you get firmer erections that last for longer. Taking acetaminophen and drinking plenty of water can help with a headache if Viagra otherwise works fine. It only comes in one dose: 50mg. Depending on your specific circumstances, your doctor may want you to: stop taking one of the medications, change one of the medications to another, change how you are taking one or both of the medications, or leave everything as is.Erectile dysfunction (ED) medications prescribed in minutes, deliverd to you in CANADA. Sildenafil (Viagra), Vardenafil (Levitra), Tadalafil (Cialis). Chat with us Any questions? . Shipping cost for Viagra to you in Canada is zero. Pocketpills offers FREE shipping anywhere in Canada to help you get access to treatment. How to get Viagra delivered . Popular Prescription Medication CIALIS VIAGRA Toll Free Phone: Toll Free Fax: 24 hours / 7 days a week See what customers have to say .