Last Sunday, I shared how I tried to track down the numbers in a health book whose author I quoted for years. Out of 47 protocols, 22 gave specific amounts (minutes, grams, or degrees) that I couldn’t link to any study. Just a week ago, Pew Research Center released a report on where many of us now pick up health advice.
What?
Pew looked at over half a million Instagram, TikTok, and YouTube posts from February to April this year. These posts came from more than 6,000 health and wellness influencers, each with at least 100,000 followers. They found that 38% of the posts promoted a product, service, or subscription, and only 9% mentioned an outside source when making a health claim.
Supplements topped the list. About 66% of posts about supplements and over-the-counter medicines promoted something. The same was true for 52% of posts about longevity and 52% about nutrition.
This study has some limits. The accounts target a US audience, and an AI sorted the posts, and its results were checked against 600 posts reviewed by people. Pew only counted if a source was named. They didn’t check if the claims were true.
So what?
That last limit matters most.
Having a named source is just the first step in checking information. The book I reviewed lists about 1,730 references, yet it still gives doses I couldn’t trace to any study. Even if a post cites a source, it can still be wrong. If there’s no source, you have nothing to verify.
A sales pitch might still be accurate, but it also shows you who benefits if you believe it.
Medical tests can get costly. A 2025 study in JAMA Network Open looked at 982 Instagram and TikTok posts about five tests, like full-body MRIs and testosterone. They found that 87% mentioned a benefit, 15% mentioned a harm, and only 6% talked about overdiagnosis or overuse. Overdiagnosis means finding something real that would never have caused you any trouble. About 68% of the accounts had a financial interest. Posts from doctors were more likely to mention the risks.
If a test finds something, it can lead to more scans, referrals, and weeks of worry. Most posts don’t show you that side.
Now what?
Before you let a post influence what you buy, take, or test, ask yourself three questions.
Who profits if I believe this? Check for things like a discount code, an affiliate link, or a clinic booking page.
Is there a specific study, and did it test this dose on people like me? Look up the study name and the number. If the number isn’t in the study, it’s just someone’s guess.
Who shouldn’t use this? If a post doesn’t mention any downsides or who should avoid it, you’re only seeing the sales pitch. For any test or drug, ask your doctor before you decide.
All three may take more time than the video, but they’re worth it.
Stay healthy.
Andre
Overdiagnosis, incidentalomas, increased health anxiety and sometimes unnecessary health spending: unfortunate outcomes TikTok informants may not account for.