Though the promises are enticing, know the facts before you reach for what one sports nutrition expert describes as “hope in a can.” Our recent investigation—including tests at an outside laboratory of 15 protein drinks, a review of government documents and interviews with health and fitness experts—found that most people already get enough protein, and some of the drinks can pose health risks, including exposure to potentially harmful heavy metals if consumed frequently. All of the drinks in our tests had at least one sample containing one or more of these contaminants: arsenic, cadmium, lead and mercury.