Cialis stays in your system for up to 36 hours and may provide support for erections during that entire time. Tadalafil will make these symptoms less severe and reduce the chance that prostate surgery will be needed. Refills: See if you can set up automatic refills or order as needed. Cialis tadalafil : This ED medication works with the same principle as Viagra, but lasts up to 36 hours. When the smaller blood vessels in the lungs become more resistant to blood flow, the right ventricle must work harder to pump enough blood through the lungs. To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and site usage information with other information we have about you. Men with BPH usually have difficulty urinating, a decreased flow of urination, hesitation at the beginning of urination, and a need to get up at night to urinate.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*.  · Cialis (tadalafil) is a prescription tablet used for erectile dysfunction and benign prostatic hyperplasia. Learn about dosage, side effects, and more. Cialis (tadalafil) is an oral medication that treats erectile dysfunction (ED). One dose of Cialis lasts longer than a dose of the well-known Viagra (sildenafil). You can take Cialis when you need it, typically 30 minutes before sex. If that doesn’t work for you, another option is taking a low-dose pill every day for ongoing erectile support.