Vilitra is effective in improving erectile function in men with ED, allowing them to achieve and maintain erections sufficient for satisfactory sexual activity. The onset of action of Vilitra varies from person to person but generally occurs within 30 minutes to an hour after ingestion. The effects of the medication typically last for about 4 to 6 hours, although individual responses may vary. Like all medications, Vilitra can cause side effects. Common side effects may include headache, flushing, indigestion, nasal congestion, dizziness, and vision changes. These side effects are usually mild and temporary.