[somebodynew]

Legislators rely on ambiguity and selective enforcement to keep laws simple. For example, the US Controlled Substances Act makes it illegal to possess a controlled substance without a prescription or license. Bufotenin is a controlled substance that also happens to naturally occur in the human body.

Congress won't write an exception to permit the possession of un-extracted naturally occurring quantities of endogenous substances within one's body because they know that the law is not enforced by robots who will automatically arrest everyone in the country. They probably never even gave the concept a passing thought because it's entirely outside the realm of what a judge would ever consider to be reasonable.

[dane-pgp]

It's worth noting that drug laws don't necessarily treat substances as being in your possession once they have been consumed, and although they might criminalize the "use" of drugs, that can require proving intent, which is not necessarily possible to establish solely from the presence of the substances (or their metabolites) in the suspect's blood.

The 1993 case State v. Lowe gives a good explanation of the legal reasoning:

"The absence of proof to evince knowledgeable possession is the key. The drug might have been injected involuntarily, or introduced by artifice, into the defendant's system."

https://www.leagle.com/decision/199383586ohioapp3d7491724