That's according to a study published in The Journal of Neuroscience.
But that possibility deserves further study, write Christian Pike, PhD, and colleagues. Pike is an associate professor at the University of Southern California's Davis School of Gerontology.
"The implication for humans is that testosterone therapy might one day be able to block the development of the disease," Pike says in a University of Southern California news release.
It's normal for testosterone levels to fall with age, but it's not clear if that process makes Alzheimer's more likely.
"The next step is to look at what the long-term effects of testosterone therapy are in aging men," Pike says.
Testosterone is most abundant in males, although females also have the hormone.
In their study, Pike's team looked at male mice with genes that made them very likely to get Alzheimer's disease. The researchers removed the gonads of some of the mice. As a result, those mice could no longer make testosterone.
For comparison, the scientists left the other mice intact.
"These results are exciting because they tell us that we are on to something that is worth pursuing," Pike says.
However, it's not clear whether the findings would apply to people.
Also, Pike's team didn't give testosterone to female mice or to male mice with normal testosterone levels.