Sure, it boosts energy and may improve sex drove. It might even take some weight off your midriff, but according to researchers at UCLA, there’s a downside to testosterone therapy: it can double the risk of heart attack. Science Daily reports that scientists at the school and at the National Institutes of Health have identified a twofold increase in the risk of a heart attack shortly after beginning testosterone therapy among men under 65 who have a history of heart disease, a finding that confirms earlier studies that found a twofold increase in heart attack risk shortly after treatment began in men older than 65. The researchers studied health care records of 55,593 men who had been prescribed testosterone therapy — 48,539 under the age of 65 and 7,054 who were 65 or older. Read more in Science Daily.