Complex sentence: Benfotiamine (rINN, or "S"-benzoylthiamine O-monophosphate) is a synthetic S-acyl derivative of thiamine (vitamin B1), which is marketed as a dietary supplement and is not a medicine.
Split into simpler sentences: Benfotiamine (rINN, or "S"-benzoylthiamine O-monophosphate) is a synthetic S-acyl derivative of thiamine (vitamin B1). It is marketed as a dietary supplement and is not a medicine.