Misperceptions about nicotine abound. Nicotine is not the main cancer-causing component in cigarettes; still, many believe it is. Nicotine makes cigarettes addictive; many people believe it does not.

Biohackers chasing the fountain of youth are turning to an unlikely new tool: nicotine. Once demonized for its role in cigarettes, the addictive stimulant is now being recast as a cognitive enhancer ...