Both Cialis and Viagra work quickly. Sildenafil treats erectile dysfunction by increasing blood flow to the penis during sexual stimulation. Language Considerations The words “female” and “women” are used here to refer to people who identify as cisgender women and who were assigned female at birth. There is also the option to take Cialis as needed. Do not take more or less of it or take it more often than prescribed by your doctor. · Descriptions. Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where . What’s more, you can find brand-name Stendra for as low as $ Save with a copay savings card. If you have commercial insurance, you may be eligible to pay as little as $0 for Stendra using a savings card from the manufacturer. You can also save 50% off Viagra for up to 12 months using a different manufacturer savings card. Dosage. The dose of Cialis you need will depend on whether you’re taking it daily or as needed. Daily doses are often between and 5 milligrams (mg). The as-needed dose is usually 10 mg but can range from 5–20 mg. The typicaldose of Viagra is 50 mg. However, the dosage can range from 25– mg.