Yes, ED pills can cause side effects. There are many safe, reliable online services offering ED prescriptions. These PDE5 inhibitors may cause headache, flushing, drop in blood pressure, or other adverse effects. The most common symptoms of erectile dysfunction include difficulty achieving or maintaining an erection and reduced sexual desire. Privacy: Confirm that your personal data and payment details are confidential. How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup. That’s not to say there aren’t just as many illegitimate sites.The four main medicines taken by mouth for erectile dysfunction are: Avanafil (Stendra). Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called . Generic sildenafil is covered by most Medicare and insurance plans, but some pharmacy coupons or cash prices may be lower. Get sildenafil for as low as $, which is 99% . Yes, if you are considering erectile dysfunction medications similar to Viagra — like Cialis, generic Viagra, and generic Cialis — it will require a doctor’s prescription. .