The generic versions are just as effective and much less expensive. When oral medications might not be safe Check with your health care team before you take any medicine for erectile dysfunction. For shipping details, please click here. Tadalafil Cialis. In some cases, online ED providers accept health insurance. If you experience chest pain, dizziness, or nausea during sex, seek immediate medical help. Please read our Terms and Conditions.Print Products and services Erectile dysfunction: Viagra and other oral medications By Mayo Clinic Staff Medicines that you take by mouth are called oral medicines. They’re often the . Sildenafil citrate (C 22 H 30 N 6 O 4 S.C 6 H 8 O 7, MW ) occurs as a white to off-white, crystalline powder that is soluble mg/mL in water. It is formulated as tablets . Depending on your symptoms and needs, you may be prescribed Viagra, sildenafil, Cialis, tadalafil, Stendra, paroxetine, or a combination of tadalafil and sildenafil, available as .