In older men, testosterone therapy is often prescribed to combat low testosterone, which can affect a man’s sex drive and muscle mass among other things. Earlier this year, the U.S. Food and Drug Administration warned that this therapy may cause an increased risk of heart attack and stroke. But a recent study published in the European Heart Journal counters that warning.

The study analyzed data from 83,000 patients and found that men whose testosterone levels became normal after testosterone therapy were 56 percent less likely to die and 24 percent less likely to have a stroke than those who were untreated.

To analyze the data, the researchers examined the health outcomes of men ages 50 and above with low testosterone levels and who were treated in Veterans Affairs medical facilities between 1999 and 2014. The research team then divided the men into three groups. The first group included men whose testosterone levels were normalized from therapy. The second group included men who received therapy but whose testosterone levels did not normalize. The third group of men did not receive testosterone therapy and their testosterone levels remained low.

The follow-up period for all three groups ranged from four to six years.

The mortality rate from heart attack and the risk of stroke improved in the group whose levels steadied, but the other two groups not see a significant decrease in mortality risks.

The researchers say they do not know why these effects are occurring and note that more research is needed. Either way, doctors warn patients that they must undergo appropriate screening, selection, dosing and follow-up to maximize the benefits gained by testosterone therapy.