Music by Cheadle Brothers www.reverbnation.com/cheadlebrothers How To Make Natural Viagra Part 2 www.youtube.com/watch?v=SLhdeamZQC4 Watermelon may be a natural Viagra, says a researcher. That's because the popular summer fruit is richer than experts believed in an amino acid called citrulline, which relaxes and dilates blood vessels much like Viagra and other drugs meant to treat erectile dysfunction (ED). Watermelon, Strawberries, Lemon and Lime.