Both Cialis and Viagra work in this way. Shake the liquid well for 10 seconds before each use to mix the medication evenly. The medication was developed by U. Viagra can be taken as long as four hours or as little as 30 minutes before sex. In addition, consider the information below. Cialis: Is one right for you? Some medications should not be taken with sildenafil.Oral medications, like Viagra and Cialis, which require a prescription and are commonly used to treat ED, can take 30 minutes to take effect, she adds. Injections take less time . Brand names for sildenafil include Viagra, Revatio, and Liqrev. The cost for sildenafil oral tablet mg is around $10 for a supply of 2 tablets, depending on the pharmacy you visit. Valid at all major chains including Walgreens, CVS Pharmacy, Target, WalMart Pharmacy, Duane Reade and 65, pharmacies nationwide. No manufacturer. Still, if your doctor says it’s okay for you to use and you end up paying out-of-pocket, you can still get the generic for a lot less than Viagra. According to price-comparison site test1.ru