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. Both options require valid medical documentation, but some online services only require a health questionnaire to be filled out and reviewed for approval—meaning no face-to-face video interaction is needed. People taking nitrates like nitroglycerin Nitrostat or isosorbide mononitrate Imdur should not take PDE5 inhibitors, as doing so could result in a dangerous drop in blood pressure. ED medications can cause side effects, and it’s crucial to have access to a medical provider if needed. Insurance: If you plan to use insurance, make sure the online provider accepts it. Yes, ED pills can cause side effects.Tadalafil is in a class of drugs called phosphodiesterase-5 (PDE5) inhibitors and is available in a generic form often called generic Cialis. Tadalafil has been on the market since . Both sildenafil (Viagra) and tadalafil (Cialis) can be used for erectile dysfunction (ED), but there are some differences between them. (1) One difference is that tadalafil (Cialis) is approved to treat both ED and BPH whereas sildenafil (Viagra) can only be used for ED. The drugs are phosphodiesterase 5 (PDE5) inhibitors, and their brand and generic names, respectively, are Viagra (sildenafil), Cialis (tadalafil), Levitra (vardenafil), and Stendra (avanafil).