It may increase your risk of dizziness or fainting. Stop using tadalafil and call your doctor at once if you have: heart attack symptoms–chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating; vision changes or sudden vision loss; ringing in your ears or sudden hearing loss; or an erection is painful or lasts longer than 4 hours prolonged erection can damage the penis. What should I do if I missed a dose of Cialis Tadalafil? Cialis: Is one right for you? Which Lasts Longer?Prescription needed: yes Accepts insurance: no Dosage: 5 mg SHOP NOW AT HIMS Healthline ‘s review Hims is a telehealth prescription company that ships a daily dosage of prescription medication. For most individuals, the recommended starting dose of tadalafil is 10 mg per day taken before sexual activity (tadalafil for use as needed). Depending on the adequacy of the response or side effects, the dose may be increased to 20 mg or decreased to 5 mg a day. The effect of tadalafil may last up to 36 hours. The dose of Cialis you need will depend on whether you’re taking it daily or as needed. Daily doses are often between and 5 milligrams (mg). The as-needed dose is usually 10 mg but can range from 5–20 mg. The typicaldose of Viagra is 50 mg. However, the dosage can range from 25– mg.