In a series of randomized controlled trials published in JAMA and JAMA Intern Med,US researchers have examined the effect of testosterone treatment in older men with testosterone levels <275 ng dl?1 on coronary artery plaque volume,1 cognitive function,2 anemia,3 and volumetric bone density.4 While the trials have shown positive resultswith respect to improvement in anemiaand bone density, longer-term studies are required to delineate the long-term risks and benefits in this population.