Complex sentence: Synthetic marijuana "is a misnomer according to Lewis Nelson, MD, a medical toxicologist at the NYU School of Medicine who states" really quite different, and the effects are much more unpredictable.
Split into simpler sentences: Synthetic marijuana "is a misnomer according to Lewis Nelson, MD, a medical toxicologist at the NYU School of Medicine." It's really quite different, and the effects are much more unpredictable.