Human growth hormone (hGH) is a $3.5 billion industry, but it's plagued by a major issue: All of the current versions of hGH (somatropin) – Novo Nordisk's Norditropin, Eli Lilly and Co.'s Humatrope, Roche AG unit Genentech Inc.'s Nutropin-AQ, Merck Serono's Saizen, Teva Pharmaceutical Industries Ltd.'s Tev-tropin, LG Life Science Ltd.'s Valtropin and Omnitrope, sold by Novartis AG's generic group Sandoz – have to be injected daily.