Synthetic opioid contamination in Brazil's illicit drug market: an emerging and underdetected risk.

Campello de Oliveira M, Castaldelli-Maia JM.

Lancet Reg Health Am. 2026 Aug 1;61:101587. doi: 10.1016/j.lana.2026.101587. PMID: 42577033; PMCID: PMC13453590.