The way i understand it is test suspension is an aqueaus solution with test oarticles suspended in it whereas base the test is in solution, no suspended particles. Also there are no esters mixed in to slow the absorption rate. In suspension the particles have to be absorbed into the body as they break down, but with base the solution of test is absorbed much faster as there ate no test particles that nred to be broken down first. I have read this in several articles. But having not used it yet I wont know if true or not for a few more days.