ED medications can cause side effects, and it’s crucial to have access to a medical provider if needed. Generic vs. These PDE5 inhibitors may cause headache, flushing, drop in blood pressure, or other adverse effects. 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. Other warning signs of an unsafe online pharmacy include outdated medication, no customer service, or suspiciously low prices. The trade-off is that the higher the strength, the greater the chance of side-effects and adverse events.Compare prices and print coupons for Cialis (Tadalafil (Cialis)) and other drugs at CVS, Walgreens, and other pharmacies. Prices start at $ Unlike other ED meds, there’s no planning required allowing you to be spontaneous and ready anytime. For a cheaper and equally effective option, get the generic version. Get Cialis Daily prescribed by a Lemonaid doctor or nurse practitioner and . Generic Cialis, or Tadalafil, is available in several doses in tablet form: milligrams (mg), 5 mg, 10 mg, and 20 mg. Depending on the dose for ED, you can use it as needed before sexual.