Can I buy generic Viagra over the counter or do I need a prescription? In the U.S. and most.What special dietary instructions should I follow? The mechanism of action for ED pills is simple: They inhibit the PDE5 enzyme which regulates the signals responsible for the smooth muscle tissue. Some services offer a subscription option where they’ll send your medications every month at a discount. However, eating food, particularly high-fat food, can reduce the effectiveness of Viagra. Tell your doctor or pharmacist if you are taking nitrates medications for chest pain such as isosorbide dinitrate Isordil , isosorbide mononitrate Monoket , and nitroglycerin Nitromist, Nitro-Dur, Nitrostat. The specific process for getting ED pills online depends on your chosen provider. Erectile dysfunction can be caused by a variety of factors , including age, cardiovascular problems, diabetes, and other conditions that affect nerve function or blood flow.Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in adults (Liqrev, Revatio) and children 1 year of age and older (Revatio) with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the . Best Low Cost: GoodRx Fastest Delivery: Blink Health: Sesame Sign Up Now Key Specs Cost: Consultation prices vary based on the prescriber; $5 generic prescriptions Medical . It is available in generic and brand versions. Generic sildenafil is covered by most Medicare and insurance plans, but some pharmacy coupons or cash prices may be lower. Get sildenafil for as low as $, which is 99% off the average retail price of $ for the most common version, by using a GoodRx coupon.It’s available in 10 mg and 20 mg tablets. Both options require valid medical documentation, but some online services only require a health questionnaire to be filled out and reviewed for approval—meaning no face-to-face video interaction is needed. You can take Viagra daily, but because the medication stays in your system for four to six hours, it will not be effective all day. This increase in blood flow results in a firmer, longer-lasting erection. Read our editorial process. We also looked at additional services, such as access to digital pharmacies and home delivery options.