An erection is the result of an increase in blood flow into certain internal areas of the penis. Some might experience headaches, back pain, or flushed skin. 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. Boosting Psychological Well-being Beyond the physical realm, the emotional benefits of Cialis can’t be ignored. The penis is one of the areas where this enzyme works. Tadalafil stops the breakdown of a chemical responsible for relaxing muscles. If you experience chest pain, dizziness, or nausea during sexual activity, call your doctor immediately or get emergency medical treatment, and avoid sexual activity until your doctor tells you otherwise.4. Bottom Line. Cialis is used to treat erectile dysfunction (ED) and to reduce symptoms of benign prostatic hyperplasia (BPH). One ‘as needed’ tablet lasts for 36 hours or Cialis is available as a lower dosage that can be taken on a daily basis, eliminating the need to ‘plan for sex’. 5. For erectile dysfunction, take Cialis just before sexual activity but not more than once per day. It can be used up to 36 hours before sexual activity. Cialis can help achieve an erection when sexual stimulation occurs. An erection will not occur just by taking a pill. Follow your doctor’s instructions. Cialis. Rather than Viagra’s 50 or mg blue pills, Cialis comes in lower doses, the smallest of which is just mg. That allows for daily use, ensuring the drug’s always in your system.