Surge in fake citations uncovered by audit of 2.5 million biomedical science papers

The reference integrity audit of 2.5 million biomedical papers spans 3 years of scientific publishing.Credit: Aramyan/Getty

An audit of 2.5 million academic papers has identified nearly 3,000 biomedical-science papers that contain fake references — ones that could not be traced to known publications.

The findings, published in The Lancet on 7 May1, are contained in the first academic study to estimate the scale of fake citations in the biomedical literature.

The authors designed an automated pipeline to screen papers from PubMed Central — a database of publicly accessible biomedical articles — published between January 2023 and February 2026.

Their work suggests that the contamination of papers with fake citations is a rapidly growing problem in biomedicine. There were 12 times more publications with fabricated citations in 2025 compared with 2023 (see 'Fabricated references on the rise').

Source: Ref. 1

The findings are “conservative underestimates”, says study co-author Maxim Topaz, an AI researcher at Columbia University in New York. “What we identified is the lower bound of true prevalence. We’re scratching the tip of the iceberg,” he adds.

Kathryn Weber-Boer, director of scientometrics at the London-based company Digital Science, agrees. The study is a “solid first initial contribution to the problem”, she says. (Digital Science is operated by Holtzbrinck Publishing Group, the majority shareholder of Springer Nature, which publishes Nature. Nature’s news team is editorially independent of its publisher.)

A Nature analysis published in April estimated that around 1.6% of publications from 2025 contained at least one reference corresponding to a publication which did not seem to exist.

Reference mismatches

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