Insurance can help you save even more on consultations and medications. If you prefer, you may contact the U. Please expect up to 4 to 6 weeks for reimbursement. If you have an erection that lasts more than 4 hours, get medical help right away. Generic vs. If you experience chest pain, dizziness, or nausea during sex, seek immediate medical help. Most online providers require a picture of a valid ID, a selfie showing your face, and a recent blood pressure reading taken with a home blood pressure monitor or by a medical provider.Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum recommended dose is mg. Don’t take sildenafil (Viagra) more than once daily (at any dose). Written by Brian Leonard, PharmD, BCACP, BCGP. Buying drugs over the internet. If you buy drugs on line, you may be putting your health at serious risk. This is especially true if you order prescription drugs without being examined in person by a health care practitioner. A simple Internet search will turn up hundreds of sites that sell drugs. Some Internet pharmacies are legitimate. Rarely reported side effects include: an erection that will not go away (priapism). If you have an erection that lasts more than 4 hours, get medical help right away. If it is not treated right away, priapism can permanently damage your penis. sudden vision loss in one or both eyes.