@miagreen,
Pls have him send me whatever supplement he's taking.
There's no normal that can be defined here. However, if you feel it's abnormal or problematic for you, then there is a problem.
Seriously, after 19 yrs, you're having daily sex and enjoying it, where's the problem? I don't know if this is all accurate, but assuming it is 100%, this guy has an unusual sex drive, isn't cheating on you..and you're not complaining about the sex. Frankly, I'm not seeing a problem here.