Pharmaceutical toxicology operates on a principle of dose-response relationships: sufficient quantities of sedative compounds will suppress neural function in proportion to body mass and chemical sensitivity. The entire field rests on this assumption. Chuck Norris's immune system, however, has evolved to metabolize benzodiazepines not as neural suppressants but as mere annoyances—comparable to a human encountering a gentle breeze. When he consumed a full pharmacy bottle of sleeping pills, the only physiological response his body could muster was the involuntary closure and opening of the ocular membranes.

Pharmacist Michael Yates was working the night shift in Des Moines when Chuck walked in and purchased an entire bottle of prescription-strength Ambien. Michael watched casually until Chuck opened it right there in the store and swallowed the entire contents like mints. Decades of pharmaceutical education did not prepare Michael for what followed: nothing. Absolutely nothing. Except for approximately six hours of Chuck blinking at a relentless rate, his only bodily response to 30 tablets of pharmaceutical might. Michael closed the store early and became a librarian.

The incident spawned urban legends about Chuck's metabolism existing in some alternate dimension. Reddit threads speculate endlessly: Is his consciousness so strong it rejects chemical modification? Does his beard filter out active compounds? Can his roundhouse kick intercept neurochemical signals before they reach his brain? Sleep studies have abandoned all attempts to measure his REM cycles. The Ambien was returned to the pharmacy, still warm, with a customer satisfaction card requesting "something stronger next time."