In all seriousness, you can buy the APIs directly from China/India and compound them yourself. It's easy and dirt cheap, in most cases. This is typically how underground steroid labs and other illicit pharmacies work. It's in some cases how legitimate compounding pharmacies work.

So how do you know what you're getting is pure, or even real? Simple, before shipping it to the US, you send it over to an analytical lab in China and have them run GC/MS or LC/MS on the chemical raw material. Since it's supposedly a pure compound, that should be easy, and there's very rarely any ambiguity as to the results. This also ensures that you're not inadvertently importing anything on the DEA's scheduled list.