PeakNootropics sells bulk powder nootropics worldwide, I suggest this supplier because of the price (ordering in powder is a lot cheaper than to buy capsules) and the high standard of purity, it has a big choice of substances ( they are currently selling 16 different nootropics) and ships fairly quickly. It’s the best nootropic supplier I found so far.

Don’t know how to choose nootropics and combine them? No problem, I’ve explained that here: How to build the perfect nootropic stack.

Need the most powerful thing out there? Go for Modafinil. This is the best vendor and has free worldwide shipping.
They sell both Modafinil and Armodafinil (read this article if you don’t know the difference: Armodafinil: the new king of cognitive enhancers).