I have just turned 59 and haven't had much of a libido for at least a year, but OH who is soon to be 71 has my share as well, is it usual for a man in his 70s to have such a good sex drive? Serious question by the way.
IMO men lose ability rather than desire which is why they invented those little blue diamond tablets. That said, I've not conducted a survey of 70+ men and their sexual desires.
Sex drive is emotional and needs to be backed up by physical manifestations and that is mainly...the ability to get an erection.
This gets increasingly difficult throughout the 60's 70's and 80's of life.
Some men are not interested and others regard it as essential for normal life.
No I haven't ever had it investigated although, I have been to see doctor, I am having blood tests tomorrow, and have never taken HRT doctors I have seen don't seem to want to prescribed it.