Just make sure you take it at the same time every day. You should take tadalafil one time a day. Your doctor will probably tell you not to take tadalafil if you are taking street drugs containing nitrates. Continue to take tadalafil even if you feel well. There are many other treatments for erectile dysfunction. One of the first Cialis ads aired at the Super Bowl.Dosage range: mg to 5 mg. Frequency: once daily, regardless of the timing of sexual activity. Cialis’s recommended dosage when it’s taken as needed for ED is as follows. Dosage range: 5 mg to 20 mg. Frequency: one dose at least 30 minutes before sexual activity, with a maximum of one dose per day*. 13 comments. A lot of compounding pharmacies make a 5 to mg/day dose. I bet you already have, but I recommend getting a comprehensive male hormone panel drawn as . Cialis lasts up to 36 hours in the body, while Viagra lasts 4–6 hours in the body. Both are taken 30 minutes before sex. Cialis can cause limb pain, while Viagra can cause vision change, rash.