In my "professional" experience, libido is directly related to hormone levels. this is in men AND women.
As men age and their testosterone drops, the drive lessens just as women have a loss in testosterone and estrogen.
Then there are women like this:
Stockholm | An 88-year-old Swedish grandmother has admitted sleeping with over 3,000 migrants in the past 5 years to “help them integrate better” to their new country of adoption reports the Dagens Nyheter.