Men undergoing testosterone therapy are at an increased risk for heart attack and stroke, research suggests. Bloomberg reports that the study also found a 29% increase in death, based on an assessment of 8,709 men in the US Veterans Affairs health system.

JAMA Associate Editor Anne Cappola told Bloomberg that the study reveals two things: that patients need to understand the risks, and that the marketing surrounding the treatments should be scrutinized.

The findings could have implications for drugs such as AbbVie’s AndroGel and Eli Lilly’s Axiron. These prescription meds are part of a market Bloomberg pegs at around $1.6 billion.

This VA study is not the first to take on testosterone. Bloomberg notes that the National Institute on Aging stopped a 2000 study over an increased heart attack risk and high blood pressure.