Psychological factors like stress, depression, or anxiety can also contribute. It’s best to check your chosen provider’s site for more information. You may attempt sexual activity at any time between doses. If you are taking tadalafil to treat PAH or BPH, follow your doctor’s directions and the guidelines in this paragraph. Other uses for this medicine This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.Drug Facts Common Brands Cialis Drug Class PDE-5 inhibitor Controlled Substance Classification Not a controlled medication Generic Status No lower-cost . Tadalafil (Cialis) is taken by mouth either as needed before sexual activity or once daily for erectile dysfunction (ED).It’s also taken once daily to treat symptoms from an enlarged prostate (benign prostatic hyperplasia, or BPH).Tadalafil (Cialis) is available both as brand-name and generic tablets. Common side effects of this medication include . AdComplete the Online Consultation with our Doctor. Personalize Your Needs. If Appropriate, Get a Prescription for ED from RexMD®. Free Shipping Available.