Is there an over-the-counter Viagra? Viagra is only available with a prescription in the United States, Canada, and most other countries. Viagra is sold under the generic name sildenafil.Some people may also have ringing in their ears tinnitus or dizziness. Avanafil Stendra. Boots is the leading pharmacy-led health and beauty retailer in the UK with over 2, stores, making this medicine widely accessible. They include dutasteride Avodart, Jalyn and finasteride Propecia, Proscar. How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup. These are commonly prescribed for an enlarged prostate or male pattern baldness. It might work longer if you have mild to moderate erectile dysfunction.Before taking Viagra, be sure to tell your doctor about all medications you take, including prescription and over-the-counter types. Also describe any vitamins, herbs, or supplements you take. Home Viagra Print Save Viagra Generic name: sildenafil (oral) [ sil-DEN-a-fil ] Brand names: Revatio, Viagra Drug class: Impotence agents Medically reviewed by Sophia Entringer, PharmD. Last updated on Uses Warnings Before taking Dosage Side effects Interactions FAQ What is Viagra? CHOOSE BRAND-NAME VIAGRA The original little blue pill prescribed by doctors for over 20 years Clinically proven to treat men with erectile dysfunction (ED) Ongoing commitment to product quality and safety monitoring Learn More IF YOU CHOOSE BRAND-NAME VIAGRA, MAKE SURE YOU GET THE BRAND NAME.Its introduction has been hailed as an important step forwards in supporting men to proactively manage their health. Please expect up to 4 to 6 weeks for reimbursement. Share this article. This medicine works best when you take it on an empty stomach an hour before sex. It works for up to 36 hours. Your doctor or other health care professional can recommend one for you based on these factors, other health conditions you have and any other medicines you take.