Lancet Journal Raises Concerns Over Old Study

A 2006 medical case report published in The Lancet, which linked infant death to codeine passed through breast milk, is under renewed scrutiny. This paper has significantly impacted global pain management and breastfeeding advice for new mothers.

The Lancet added an 'expression of concern' on January 20, 2026, following allegations of falsified toxicological data, authorship issues, and ethical concerns. These allegations surfaced after a year-long investigation by The New Yorker and years of Canadian media coverage.

Critics argue the paper, authored by Gideon Koren, has been debunked for years. Outside researchers and two other medical journals have already retracted similar versions. The case study, focusing on an Ontario infant's 2005 death, purported that Tylenol 3, a common postpartum pain reliever containing codeine, was responsible.

Pharmacologist David Juurlink contends Koren misinterpreted toxicology results, suggesting the infant's high drug levels indicated direct administration rather than breast milk transmission. The Motherisk lab, founded by Koren, faced independent reviews deeming its testing methods unreliable, leading to its closure in 2019. Koren relinquished his medical license that same year.

Despite the criticisms and retractions of similar papers, the original case study has been cited over 600 times. Health Canada issued warnings in 2008, and drugmakers were urged to update labeling for codeine-based medications, affecting how postpartum pain medication is prescribed and potentially leading mothers to avoid breastfeeding.