Missed a Dose You should never miss a dose of Cialis 20 mg tablet and take the missed dose as soon as possible. Thus its use in breastfeeding women is insignificant. Make sure to get an estimate of when you can expect your prescription in the mail. You should also call your insurance company to see if they cover erectile dysfunction medications. Your health information should remain between your provider and yourself.Fastest Delivery: Blink Health.: Sesame. Sign Up Now. Key Specs. Cost: Consultation prices vary based on the prescriber; $5 generic prescriptions. Medical Consultation . 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 . Cialis (tadalafil) is a prescription tablet used for erectile dysfunction and benign prostatic hyperplasia. Learn about dosage, side effects, and more.