Sulbutiamine
Sulbutiamine is man-made chemical similar to the B vitamin thiamine. Unlike thiamine, which dissolves in water, sulbutiamine dissolves in fats. Sulbutiamine is able to increase thiamine levels in the brain, and thought to be used as a stimulant in athletes.

People take sulbutiamine by mouth for Alzheimer’s disease, weakness, athletic performance, depression, diabetic nerve damage, erectile dysfunction, fatigue, and memory.

It is not fully understood how sulbutiamine works. However, it seems to have various effects on the brain that might improve memory and reduce feelings of weakness.

Source: WebMD