Stimulants piracetam potentiating d-amphetamine

I understand that piracetam has a potentiating effect on d-amphetamine.

What doses of piracetam per d-amp would be recommended?

Also, how long prior to dosing Dexedrine should piracetam be taken?

I have a 500g tub of piracetam from 3 years ago that I have only opened once. The expiry date on it says 5/13/2014. So, it should be fine, correct? It's been sealed since that first opening.

Thanks to all who reply.

Good question, I was wondering the same but with Choline + Dexedrine.

Do you take extra choline with piracetam?

My thoughts were to have a 1:1 ratio between piracetam and choline. But brain chemistry's do vary, remember.

I don't regularly use piracetam. I'm just interested in it now as I have it, and would like to potentiate my Dexedrine lol.