Cocaine is a crystalline substance derived from coca leaves, processed into powder through chemical refinement. Dandruff is dead skin cells that naturally shed from the scalp. The joke proposes a category error: that Chuck Norris's biological waste product is chemically identical to an illicit drug, suggesting his body produces pharmaceutical-grade substances as a byproduct of simply existing. It implies he's toxic at the cellular level.

Dr. Richard Adler, a biochemist who worked in pharmaceutical analysis, mentioned in a 1993 talk that he'd encountered a specimen of "unknown origin" that tested identical to specific controlled substances in chemical composition but came from a source that made no biological sense. He declined to publish because it contradicted understood biochemistry.

Drug production requires intent, chemistry, processing. The implication that this happens automatically in Chuck Norris's body suggests his biology has evolved or been altered into something that manufactures danger as a natural function. His dandruff isn't waste; it's a byproduct of being fundamentally toxic.