BMJ Group retracts apple cider vinegar weight-loss trial and bars further citation

BMJ Group has pulled a March 2024 study that linked daily apple cider vinegar to substantial weight loss, saying the findings are not reliable enough to keep in the scientific record ^[1][3]. The publisher also told journalists and others to stop citing the paper ^[1][3].

The trial appeared in BMJ Nutrition, Prevention & Health and came with a press release, which pushed its results into international news coverage ^[1][3]. It enrolled 120 adolescents and young adults in Lebanon who were overweight or obese. For 12 weeks, some took small daily doses of vinegar and others took a placebo. The vinegar group was reported to have shed roughly 9% of body mass ^[2]. Coverage at the time put that figure alongside results from prescription obesity drugs such as Ozempic and Wegovy ^[2].

Criticism arrived quickly. Researchers filed critiques, some of which the journal published as letters ^[1][3]. BMJ's content integrity team then sent the paper to outside statisticians, who tried to reproduce the numbers and to check whether the underlying data supplied by the authors held up ^[1][3].

They could not reproduce the results. The statisticians logged multiple analytical errors and found irregularities in the data set, and their report, appended to the retraction notice, said the data from each participant needed further independent scrutiny ^[1][3]. The notice is dated September 23, 2025 ^[3].

BMJ's stated grounds for retraction included the statistical approach, implausible statistical values, doubts about the raw data's reliability, thin reporting of methods, and the absence of prospective trial registration, which the publisher said violates its editorial policy ^[1][3]. The authors described the errors as honest mistakes and backed the retraction ^[1][3].

"Tempting though it is to alert readers to an ostensibly simple and apparently helpful weight loss aid, at present the results of the study are unreliable," said Dr. Helen Macdonald, BMJ Group's publication ethics and content integrity editor, adding that "journalists and others should no longer reference or use the results of this study in any future reporting" ^[1][3].

Eric Trexler of Duke University, among the scientists who flagged problems within weeks of publication, told NPR that "the magnitude of effect for weight loss seemed implausible" at first glance and that he wished the journal had moved faster. Concerns were sent to BMJ in June 2024, and more than a year passed before the retraction ^[2]. Marion Nestle, professor emerita of nutrition and food studies at New York University, told NPR, "The big surprise is why the BMJ accepted the study in the first place" ^[2].

Bragg Live Food Products, which markets apple cider vinegar, issued a statement playing down the retraction, saying it "never relied on this study to support our acetic acid claims" ^[2].

Journal editor in chief Martin Kohlmeier said publishing without trial registration "was the wrong decision to make" in hindsight, noting that the authors come from a research environment underrepresented in nutrition science and that clinical trials are relatively unusual in that field because of the participants and time required ^[1][3].

Why it matters for patients

The roughly 9% figure spent more than a year circulating as evidence that a kitchen staple could match prescription weight-loss medicine ^[2]. It can no longer be used that way ^[1][3]. Anyone who saw the comparison in a news story, a social media post or a product pitch should treat the number as withdrawn.

Nothing here changes the regulatory status, approved uses or labeling of semaglutide (Ozempic, Wegovy, Rybelsus) or any other GLP-1 medicine. No agency action tied to the retraction has been announced ^[1][2][3].

The episode also shows how much weight a single small study can carry before anyone verifies it. This one got a press release and global pickup despite lacking prospective registration, a point BMJ's editors now say was a mistake ^[1][3]. The outside statisticians' report asks for further independent scrutiny of the participant-level data ^[1][3].

What happens next

The retraction notice and the appended statistical report are public ^[1][3]. No timetable for any further review of the data has been disclosed, and neither BMJ, the authors' institutions nor any regulator has announced additional steps ^[1][3].