The widespread familiarity of the M367 imprint has made it a frequent target for illicit pill counterfeiters. Public health advisories from the DEA and forensic state laboratories consistently highlight that millions of pressed counterfeit tablets entering the illicit market mimic authentic pharmaceutical stamps, including Mallinckrodt's M367 imprint.
Underground laboratories use industrial pill presses to replicate the exact dimensions, white color, and scoring lines of authentic M367 tablets. Instead of laboratory-grade hydrocodone and acetaminophen, these counterfeit copies often contain lethal doses of illicit fentanyl mixed with binding powders. A single pressed fake can contain anywhere from 1 mg to over 5 mg of fentanyl, easily exceeding lethal toxicity levels for any user lacking medical oversight.
Legitimate M367 pills feature crisp, uniform debossing, hard tablet edges that do not crumble when handled, and consistent chalk-white coloration. Any tablet obtained outside a state-licensed retail or hospital pharmacy carries high contamination risks. Utilizing professional pill identifier tools and retaining medicines in their original prescription bottles remains the only dependable way to guarantee chemical purity and stay clear of dangerous legal scrutiny.
