3-fpm No effects?

I bought 2 samples of 3-fpm from vendors i trust to deliver quality products, and have been researching them for the past few hours with no results. I have tried 3 methods of ingestion, at large doses and i have noticed no effects that couldn't be attributed to placebo. Both products are a crystalline powder which match the physical profile described by other users.

Why could this happen? Do you think both vendors could have sent me bunk product (both uk vendors). They both have excellent reviews for this particular product. Im just a bit confused.

Edit: About 10 hours since first dose, and i can say i definitely experienced something. It felt not too different from when i was able to get an effect from high doses of caffeine. Now i have a very dry mouth which turns out to be a side effect. Perhaps i just have a natural tolerance and dont really get much of the stimulation. Thanks for your answers everyone :D.