Concentrated ammonia solutions are strong mineral bases that can induce severe lesions of the upper gastrointestinal tract when ingested. Little is known about the circumstances of poisoning with these solutions. The aim of this study was to compare ammonia exposure between patients who were drug users or abusers with non-user patients. A retrospective study was conducted on the Poison Control Center in Marseille (PCCM) data over a period of 11 years (2009–2019). A total of 614 patients were registered with 564 non-user drugs (NUD) and 50 patients with drug use or addiction (UD). Results founds that UD patients contacted the PCCM mostly for oral exposure (86%), whereas NUD patients were exposed to inhaled ammonia (64%). Repackaging accidents were the major circumstance of poisoning in UD patients (68%) with predominant digestive symptoms (86%). Severity scores evaluated according to the PSS were higher in UD patients even if only the oral route is considered (72% PSS≥2, P<0.001). Only one death was recorded, in a 65-year-old patient with a history of alcoholism. The annual number of poisoning cases in UD patients was increasing with 56% patients reported during the last two years. Medical teams in contact with patients at risk need to be made aware of this type of accident, which may be rare but can have potentially catastrophic consequences for the user and their close family and friends.