Synthetics can stimulate but in the long run you WILL fall. It's like whipping a tired horse. He may go a few more furlongs but he's going to drop after that.
Also consider the source of the information. If its from most established media journals watch out.
As far as testamonials, well, I only listen to folks that have been there. I've been there, Barefoot has been there, Azurite has been there and a few others on these forums have been there. None us that have been there promote synthetic vitamins and offer strong warning against them. Consider the source.
The so-called scientific journals and most testamonials cannot be considered. Hidden agenda - They want your money.