it can help, but such effects are secondary.
with respect to skin elacticity the most important thing is age.
after that
hydration-internal (water) and external (good hydrating lotion)
avoiding sun exposure to loose skin
if you smoke- STOP
partial list of supps/drugs that can help
GH
Vitamin C
Glucorell
vitamin E both topical and internal (get gamma tocopherol or mixed tocopherols)
reducing estrogen levels (though too far and it may have the opposite effect)