They enhance the effects of a chemical the body makes that relaxes muscles in the penis, called nitric oxide. The body takes longer to absorb it after a high-fat meal or alcohol. Payment options: Consider how you’d like to pay. It’s available in 25 mg, 50 mg, and mg tablets and lasts up to 18 hours. Sildenafil Viagra. This medication is taken with or without food an hour before sex. As with sildenafil, a high-fat meal or alcohol keep the body from absorbing it as quickly.It’s a prescription drug used to treat symptoms of ED and benign prostatic hyperplasia (BPH), or both ED and BPH, in adult males.* Cialis comes as a tablet you . Take tadalafil (Cialis) as prescribed by your provider. If you’re taking tadalafil (Cialis) as-needed for ED, you should take no more than one dose per day. The effects .  · Cialis (tadalafil) is prescribed to treat erectile dysfunction and symptoms of benign prostatic hyperplasia. It comes as a tablet that’s taken as needed or once per .