What is a drug?

[serotonin2A]

It's a mistake to define a drug based on endogenous vs exogenous. Low concentrations of morphine are biosynthesized in the brain, and DMT and melatonin are produced as well. A drug is a chemical that is introduced to the body to alter physiology.

 

[Solipsis]

What is a drug?

(David Nutt / according to a neuroscientist)

"something that when given to a rat results in a scientific paper"

 

[ebola?]

Hah...honestly, that's the kind of answer I think this question deserves.

 

[Sprout]

Apologies for my poor nomenclature - I was referring to an externally administered substance.