YouTube videos about prostate cancer put patients at risk of harm due to misleading medical information, a team of researchers have claimed.
Scientists from NYU's School of Medicine analyzed the 150 most popular YouTube videos on the disease and said 77% had factual errors or pushed content in the video or comments section.
Their work, published in the European Urology magazine, found that although 75% of the videos fully described the benefits of different treatments, only 53% warned about their side effects.
According to the team, 19% of the videos also recommended alternative and non-medical medicines – some of which could directly damage patients.
One video "prostrate herb spray" promoted the prostate to treat cancer.
The researchers said that the audiences for these videos were large, with the maximum viewers being 1.3 million.
"Our study shows that people need to be watched by many YouTube videos on prostate cancer," said the urologist Dr Stacy Loeb, who chairs a panel of social media experts for the American Republic of the Republic (AUA).
"There is valuable information in them, but people need to check the source to make sure it is credible and aware of how fast videos are old-time as care guides develop consistent with science. "
Dr Loeb said that credible online sources for information about prostate cancer are widely available. In the UK, the NHS website Offers details of diagnosis and treatment.
He added that the number of videos on YouTube makes it impracticable for medical experts to continually review them as part of any "policing" effort.
However, he suggested that doctors and viewers should use the YouTube reporting feature to warn the huge technology for videos that promote misleading information.
YouTube spokesperson was not able to respond Sky News immediately when contacting them.