Where do I start?
Well 40 is not the new 18.
At 40+ when you bust your ass and lift and diet and do everything right you are just waisting away. No pun or joke intended. You will not regenerate. It just does not happen.
From the skin on your face to the the hair on your head peptides like hGH help.
Your sex drive well that one everyone knows about.
Person view is the peak time of your life. Marcus can elaborate from his point of view on this one.
I feel that with use of aas/hGH in place of peaking in your late 28s you actually peak in your 40s. Hence the reason why so many bodybuilders and power lifters are 35+... It does have a lot to do with life style also.