Flexuline These medications are often used to treat erectile dysfunction. They include sildenafil (Viagra and Revatio), tadalafil (Cialis and Adcirca) and vardenafil (Levitra and Staxyn). Side effects are headaches, hot flashes, changes in vision and a blocked nose. How to increase penis size with herbs If you want to increase the size of your penis, there are many herbs that you can use to increase blood flow to that area and help you keep it erect temporarily. Some of the most permanent natural solutions to increase its length and width include changes in your daily diet, exercising more and losing weight in the abdomen area. These options are simpler and safer than exposing yourself to surgery. Keep reading this article to learn how to increase the size of your penis without resorting to medications or surgeries. Part 1 Use herbs to increase blood flow to the penis.