A hormone-free drug tested in male mice might someday prove viable for men who want their own birth-control pill, according to new research.

The compound stifles sperm production but not sexual activity; fertility returns once treatment stops, and males can go on to father healthy offspring, the researchers say.

Lead researcher Dr. James Bradner, of the Dana-Farber Cancer Institute and Harvard Medical School in Boston, said, "The molecule used in this study, JQ1, is a prototype drug," explaining it is not intended for human use. "We have successfully administered the agent to animals by mouth, but notably in this research, JQ1 was injected into the belly of the mice and rats studied."

JQ1 works by targeting a protein called BRDT that functions in the testes and is vital for fertility. Unlike previous drugs, JQI can physically reach the cells that make sperm. Sperm cell production drops in number and surviving sperm don't work as well.

Read more from U.S. News.