Professional athletes are banned from using human-growth hormone because it is a performance-enhancing drug. It's the same substance Peyton Manning has denied using after Al Jazeera accused that HGH was delivered to his wife in a controversial documentary. Endocrinologist Dr. Stuart Weinerman told INSIDE EDITION it's not uncommon for women to use HGH, due to claims of its anti-aging effects. But using HGH may have a dark side; Weinerman says the side effects of HGH are not fully researched. #InsideEdition