Been mod on most of the BB/steroid boards based in the US, but ill keep it simple my answer.
Some supplements can give you an edge if only psychological still it helps and some really give you a edge in terms of energy/pump..Good diet,train correct,use protein if all this is in order then you can try lets say No Explode or V12..
But to gain size and fast their is only one option,
Anabolic steroids or peptides like hgh,igf-l3 and other new ones out their..
Same goes to burn fat,
A combo of lets say T3,Yohimbine and Clenbuterol will work wonders..
Many people i know in the age of 30-45 use testosterone therapy or hgh on a daily basis.