Both Vardenafil (Levitra) and Sildenafil (Viagra) are erectile dysfunction medications that are typically given before to sexual activity; however, the best option will depend on your age, medical conditions, other medications, and how your body reacts. They might cause dangerous side effects like low blood pressure, dizziness, headaches, or heart issues, therefore they should only be taken under a doctor's supervision, especially if you have heart disease, high blood pressure, diabetes, epilepsy, or take nitrate medications. Avoid taking both at the same time or taking more than the recommended amount. Instead of self-medicating if erection issues are common, see a doctor to determine the underlying cause.