She stresses that the lesson from this study should not be that men go out and start taking testosterone as they age. "This is an observational study, and all we have found is an association," Laughlin says. "Until we can do the randomized placebo controlled trials, we don't even know that testosterone is safe for men."
It is abstracted from normal speed VOA.I can not understand "do the randomized placebo controlled trials".Thx
about "placebo controlled"
Placebo-controlled: A term used to describe a method of research in which an inactive substance (a placebo) is given to one group of participants, while the treatment (usually a drug or vaccine) being tested is given to another group. The results obtained in the two groups are then compared to see if the investigational treatment is more effective than the placebo.