Social media influencers are ‘fearmongering’ to promote health tests with limited evidence, study finds

Influencers are appealing to emotional narratives around health and often “fearmongering” to promote controversial medical tests on social media, a new study has found, in ways that are overwhelmingly misleading and fail to mention potential harms.

The research, led by the University of Sydney and published on Thursday in the American Medical Association’s open access journal JAMA Network Open, investigated five tests being discussed on social media despite limited evidence of their benefits for generally healthy people and concerns about overdiagnosis.

These were full-body magnetic resonance imaging (MRI) scans; genetic testing claiming to identify early signs of 50 cancers; blood tests for testosterone levels; the anti-Mullerian hormone (AMH) or “egg-timer” test, which surveys a woman’s egg count; and the gut microbiome test.

Researchers identified 100 posts for each test on Instagram and TikTok respectively between April 2015 and January 2024. Excluding posts from accounts with fewer than 1,000 followers and in languages other than English, they analysed the resulting 982 social media posts, from account holders with more than 194 million total followers.