Stendra avanafil : This is an as-needed medication taken 30 minutes before sex and can last up to six hours. Children 1 year of age and older weighing 45 kilograms kg or more—20 mg 3 times a day. However, others work on a cash-pay basis and don’t partner with insurance companies. Use only the brand of this medicine that your doctor prescribed. The specific process for getting ED pills online depends on your chosen provider.Sildenafil (Viagra). This medicine works best when you take it on an empty stomach an hour before sex. The body takes longer to absorb it after a high-fat meal or .  · For treatment of erectile dysfunction: For oral dosage form (tablets): Adults up to 65 years of age—50 milligrams (mg) as a single dose no more than once a day, 1 . In people having trouble with erections, PDE-5 may work too quickly. Viagra works by blocking the PDE-5 from working. This way, blood flow to the penis can occur .