I tried some indian knock-off in 2009 and some piracetam manufactured locally (in Belarus,) none had any effect on me. I wonder if indian knock-off wasn't modaf

I tried some indian knock-off in 2009 and some piracetam manufactured locally (in Belarus,) none had any effect on me. I wonder if indian knock-off wasn't modafinil at all. I had no any side effects even after bumping to 500mg. I wonder if these drugs have selective effectiveness?