Here are some key factors to consider when deciding: Pricing: Know how much your monthly supply will cost with shipping and tax. You can see an in-person provider or speak with a doctor virtually. It may be difficult to remain firm despite wanting to have sex. Never purchase ED medications from a site or service that doesn’t require a prescription and medical documentation. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.Drug details Here are some details on sildenafil: Drug class: phosphodiesterase type 5 (PDE5) inhibitor Drug forms: oral tablet, liquid suspension, intravenous (IV) bolus injection Brand-name. The usual dose is 50mg, when you need it. Do not take it more than once a day. The dose can be increased to mg or decreased to 25mg depending on its effect. Take sildenafil up to 4 hours before you want to have sex. For sildenafil to work properly, you’ll need to be sexually excited. 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. Quoted prices are for cash-paying customers and are not valid with insurance plans.