Sulbutiamine is a synthetic derivative of thiamine (vitamin B1).
It is used to treat asthenia (symptoms of fatigue or weakness), though is not clear if it is effective in alleviating tiredness.
Sulbutiamine is also used to treat thiamine deficiency and poor concentration. Being a potent cholinergic anxiolytic, Sulbutiamine is a popular nootropic, with users reporting enhanced memory, focus and improved mood and motivation. Endurance athletes may use it to try to enhance their performance.