Click Here To Order Cialis Most men with ED are prescribed to take Cialis at least 16 minutes before the estimated sexual activity. Cialis dosage is an oral drug prescribed for the treatment of erectile dysfunction (ED) in men. It contains Tadalafil which works by relaxing the smooth blood vessel walls and increasing the blood flow to the penis. This action helps you achieve or sustain an erection firm enough for sexual intercourse. It is usually recommended to be taken approximately 30 minutes to 1 hour before any sexual activity. The effects of this medicine last in your body for around 36 hours. You can take this medicine when you need it. Take this pill with the doctor’s word for the best sexual arousal.