Shareholders don't have too much to fear -- yet.The diabetes medicine Ozempic has been a veritable cash cow for Novo Nordisk (NVO -1.22%). The company's revenue, earnings, and stock price have been on a tear in recent years -- and no single drug has contributed more to its performance than Ozempic.However, various potential headwinds have popped up that could disrupt Ozempic's progress. One of them is competition. Novo Nordisk's longtime foe in the diabetes market, Eli Lilly, developed Mounjaro, a diabetes ...