Nicotine, by a very wide margin.
Nicotine is the most abused substance and its use causes the most diseases and deaths.
Sugar, followed by salt.
Many people mistakenly believe that it is alcohol. However, nicotine is the most abused substance and its use causes the most diseases and deaths.Read more: Most_abused_substance_in_the_us
dog
cocaine
crystal meth is probably the most abused as its highly addictive. but crack cocaine is also among the top.
cocaine
marijuana.
I believe that Crest is the most commonly used toothpaste in America.
Marijuana is definitely the most widely used illegal drug in the US. Marijuana is the most widely used illegal drug.
In general use, "substance" refers to a particular kind of matter with uniform properties. In philosophy, it can refer to an individual concrete entity that can exist independently. In the context of addiction, substance refers to drugs or alcohol that are abused or misused.