Transfusing young blood and freezing heads may get most of the anti-aging and life-extension buzz, but don’t count out the molecule hunters: After setbacks and stumbles and what critics called debacles, these scientists are figuring out which biochemicals might potentially, possibly be fountains of youth in pill form.

In the latest advance, biologists reported on Thursday that a molecule already sold by supplement makers (even as scientists scramble to understand it) restored youthfulness to blood vessels in 20-month-old mice, an age comparable to 70 years in people. The research supports the idea that boosting certain genes and molecules that fade with age could keep people functional, resilient, and even spry well into their 80s, even without living longer.