Health videos are hugely popular on social media. While the platforms can be great ways to learn more about certain conditions or treatments, a new study found that many influencers are promoting medical tests that could do more harm than good.
The report—published on Feb. 26 in JAMA Network Open—found that the large majority of online posts discussing medical tests do not include any evidence-backed facts about the benefits and harms of those tests.
Investigators evaluated 982 English-language social media posts on Instagram and TikTok. These centered on five medical screening tests: full-body MRI scans, cancer blood tests, testosterone tests, hormone tests to measure egg count, and gut microbiome tests.
Most of the posts failed to mention the risks of overdiagnosis, misdiagnosis, and other harms that can come with these medical tests.
Among the posts, about 84% had a “promotional tone,” the study found, and 68% of the account holders had some sort of financial incentive for talking about a specific medical test on their page. Over half of the posts recommended that people “take action and get the test.”
However, the study also found that posts made by doctors were more likely to discuss harms and less likely to endorse the tests.
“The vast majority of these posts were overwhelmingly misleading,” study author Brooke Nickel, PhD, research fellow at the University of Sydney School of Public Health, said in a press release. “They are being promoted under the guise of early screening, as a way to take control of your own health. The problem is they are unnecessary for most people, and, in some cases, the science backing their efficacy is shaky.”
Here’s what experts had to say about these five popular medical tests and how to determine if you should actually get one.
Also known as whole-body magnetic resonance imaging (WB-MRI), this medical procedure scans your entire body for cancer or tumors, among other potential health issues. In fact, one full-body MRI scanning company claims to check for upwards of 500 conditions. There’s no radiation involved, and it takes about 40 to 50 minutes. They can cost around $2,500.
And they seem to be becoming more popular, Mina Makary, MD, clinical associate professor of radiology at The Ohio State University Wexner Medical Center, told Health.
“I have seen increased interest by the public due to the increased coverage on these tests on social media and by some influencers and celebrities,” he noted.
The scan is recommended for some people with cancer or those who are predisposed to it, but there are risks, too.
“There are no standard protocols for WB-MRI, and it’s common for the WB-MRI exams to vary from one facility or scanner to the next in the type of images obtained and quality of exam,” Makary said.
After the scan, you receive a report. However, the average person may not know what to do with that information next, experts warned.
“Only centers that specialize in high-risk screening have experience and expertise in interpreting and managing the results of these scans,” Michael Rosenthal, MD, PhD, senior physician at the Dana-Farber Cancer Institute and an assistant professor of radiology at Harvard Medical School, told Health.
And the results themselves may not be all that helpful. Full-body MRIs frequently detect false positives, which can be stressful for patients. You could also be diagnosed with something that doesn’t yet need care.
In both of these cases, people can end up getting unnecessary procedures such as biopsies. Though beneficial in the right settings, biopsies can also cause complications that harm patients, Rosenthal said.
Because of these risks, the test isn’t recommended if you’re healthy.
“The practice is not supported by any recognized medical society, payer group, or public health program because the harms outweigh the benefits,” Matthew Davenport, MD, a professor of radiology and urology at the University of Michigan, told Health.
“A patient is more likely to be harmed than helped from this practice because of the overwhelming identification of findings that will not benefit health, but will trigger extensive work-up and intervention, and their related complications,” said Davenport.
Multi-cancer early detection (MCED)—or, multi-cancer detection (MCD)—tests are relatively new technology, and they check for certain substances shed by cancer cells, rather than the cancer itself. This might include abnormal DNA fragments or proteins from cancer tumors that end up in the bloodstream.
However, these cannot diagnose a person with cancer—they can only offer a prediction.
Test manufacturers say the tests can screen for more than 50 cancers before symptoms first appear. But with many of these tests still in clinical trials, Nickel’s team said the evidence doesn’t effectively show that the benefits will outweigh the harms.
If you receive a positive test result, you’ll need additional testing to confirm whether there’s actually cancer present in the body. However, that testing may often turn out to be unnecessary—some research suggests that over half of people with a positive MCD test don’t actually have cancer.
There is a blood test for colorectal cancer, specifically, that was approved by the Food and Drug Administration (FDA) in August 2024. But for now, no MCD tests that claim to look for multiple cancers have been authorized by the agency.
These tests can also be expensive. The Galleri test, which is the most popular MCD, has a list price of $949.
Also called the egg-timer test, the anti-Müllerian hormone (AMH) test measures levels of this hormone, which is made in the ovaries and testicles.
The test—which can retail anywhere between $15 and $200—can quantify how many eggs are in your ovaries, help determine what stage of menopause you’re in, or suggest how well you might respond to fertility treatments.
Many companies promote it as a fertility test, and people on social media are biting.
However, AMH tests can’t predict your chances of conceiving since they can’t determine the quality of your eggs. They also can’t determine the specific age at which you will enter into menopause.
“Experts do not consider it to be reliable,” Nickel said in a press release. “There is the concern that a low result discovered outside the context of a specific medical issue may drive some women to unnecessary, costly fertility interventions.”
There’s concern among researchers that, on the other hand, the test could give users a false sense of security about delaying pregnancy.
“These tests are useful, but it is the interpretation of these tests which requires a clinical conversation,” Scott Nelson, MBBS, PhD, professor of reproductive and maternal medicine at the University of Glasgow, told Health.
A test that can measure organisms in your microbiome—and then tell if you might have health issues—may sound alluring. After all, there’s plenty of research linking gut health to overall health.
Gut microbiome tests, which are often done with fecal samples, can look for different things, such as which specific microorganisms are prevalent in the gut or how many pathogens there are. Other tests can calculate a gut health score and provide some tips on how to improve it.
They usually retail for a couple hundred dollars.
But, Nickel and her team wrote, Instagram and TikTok posts on gut microbiome tests promise “wellness via early detection of many conditions without good evidence of benefit and concerns about medical overuse causing harm and waste.”
Though there are a number of tests available online, only one test is FDA-approved.
Low testosterone blood and saliva tests claim to tell if men or women have low testosterone levels, and they generally cost between $70 and $150.
However, the long-term safety of testosterone replacement therapy on cardiovascular health and mortality is still unknown, Nickel warned.
The tests are “often marketed to men using fear-mongering tactics to then promote testosterone supplements which claim to enhance masculinity and sexual performance,” Nickel told Health.
She said there’s a danger of overusing treatments in response to an abnormal result. Low testosterone therapy has been associated with an increased risk of exacerbated sleep apnea and a greater risk of blood clotting.
When people see these medical tests pop up on their social media feeds, it’s understandable why they might be interested in purchasing one.
“People are making use of these tests due to social media influences coupled with a very real and understandable desire to extend health and life,” Rosenthal explained. It’s also natural to assume minimizing the risks of something would be potentially beneficial for your health, he added.
However, medical guidance from social media is often “problematic because it is not anchored to good medical evidence and is provided by people who usually have no expertise in the area,” Rosenthal said.
If someone does end up getting one of these other tests, the results might be unreliable, or they might be taken out of context when the patient tries to interpret them, experts said. Plus, taking action after a test can sometimes lead to unnecessary follow-up testing, as well as needless spending and anxiety.
“The buzz that you are hearing on social media and online is almost all driven by companies looking to capitalize on people’s worries,” Christopher Hess, MD, PhD, chair of the department of radiology and biomedical imaging at the University of California, San Francisco, told Health. “Screening tools like MRI are great for their wallets, but not so great for improving the health of the people to whom they advertise.”
If you do end up getting one of these or other medical tests, look into the credentials of the lab testing your sample. “Consider the source, and look to confirm what you see using other sources of information from reliable, evidence-based sources,” said Hess.
But in general, Hess advised, don’t believe everything you see on social media.
“Information on medical testing should come from your doctor, not from your favorite media personalities,” said Rosenthal.
