The Red Flags of Quackery
The Red Flags of Quackery
How to spot bad medical info from a mile away
You are what you read.
Much like the common adage about the impact of diet on your body, your mental and intellectual health is heavily influenced by the quality of information you ingest. Yet we live in an era with so much information it can be hard to keep up, let alone figure out what’s true or valuable within the sea of garbage online.
Pseudoscience and quackery are everywhere these days. Joe Rogan, one of the most popular podcasters in the world, frequently brings on guests who spread misinformation about everything from global warming to COVID-19. Celebrities like Gwyneth Paltrow peddle nonsensical health and wellness treatments for money. Robert F. Kennedy Jr., a prominent anti-vaccine crusader, is running for President to raise the profile of his incorrect and misguided views. And you don’t have to look any farther than the top “Science” newsletters on Substack:
I am pleased to see
at the top—she’s an excellent resource I recommend (and will discuss below). Unfortunately, a lot of the others in the top 10 publish poor quality information. Those in red boxes are anti-vaccine (especially with regards to COVID) and/or push other bad medical advice. The ones in green advocate fringe “red pill” type content about gender and LGBTQ issues.Disturbingly, #3 is written by several prominent physicians, including Vinay Prasad, MD, MPH. They advocate very contrarian views on COVID, particularly regarding vaccination and non-pharmaceutical interventions. Their anti-establishment streak is bleeding into other topics in medicine, and in my view, some of their content recklessly endangers public health.
I’m sure if we were to ask Substack founders like
what they think about this list they would probably say something along the lines of “We believe in free speech and letting readers choose the views they want to hear more from” and “we think your assessment of some of those publications is an oversimplification.”Fair enough, the marketplace of ideas is merely matching public demand (and lots of people do want to read crazy nonsense!) In that case I would like to use the rest of this post to inform the “consumer” so they can be more discerning, and potentially shift their media “diet” to healthier choices.
A Checklist of Red Flags
It’s not enough for me to just name and shame some of the worst offenders on Substack, the internet is full of people trying to sell you bad health advice. In order to “vaccinate” yourself against pseudoscience, here are some red flags I look for when assessing new medical sources on the internet:
🚩 Does this person have ANY relevant expertise?
To be clear, I’m no fan of #TrustTheExperts, and blind deference to authority can be just as dangerous as reflexive skepticism (case in point: some of the people on the list above are doctors with prestigious pedigrees!) It’s also unquestionably the case that people with training and experience outside medicine can have valuable insights; citizen journalists can shed light on malfeasance. That said, if some random person with no biomedical background is making bold claims about protein structures or genetics or viral replication that contradict pretty much everyone else with expertise in the area, there’s a good chance they’re simply wrong!
The comedian Marc Maron has a side-splitting bit about that personal trainer everyone knows who keeps saying you gotta take weird supplements like turmeric:
🚩 Do they provide context about their sources?
A lot of people who traffic in quackery will “cite” studies in the sense that they mention “a Harvard study found,” or “top doctor at Mayo clinic says,” but they tend not to link the source directly. This is a neat sleight-of-hand where they make an “argument from authority” (a logical fallacy) sound like they’re just following the evidence. When you chase down the reference, very often they are taking comments and findings out of context, sometimes misinterpreting them completely (based on the red flag above, it can be difficult to tell if this is deliberate or simply because they don’t have the basic background to even understand what they’re reading). Look for someone who provides adequate framing around conflicting data, ideally linking to the primary sources.
🚩 Does this person claim to have “secret knowledge” that “the establishment” “doesn’t want you to know”?
Conspiracy-theory adjacent language is always a red flag for me. Pitting “us versus them” is a classic technique demagogues use to sow division and solidify trust from their followers. Does the mainstream consensus always get it right? Of course not, scientists and doctors are human, and we all make mistakes. But legitimate medical and scientific sources try hard to prove their points in public through peer-reviewed research, transparency about their methods, and openness to being challenged by people who disagree. This brings me to…
🚩 Are they willing to change their mind or admit when they’re wrong?
Willingness to change your views in light of new evidence is the cornerstone of the scientific method and evidence-based medicine. Almost without fail, media personalities who are not legit will continue to spin elaborate tales about how every new data point actually proves they were right all along. RFK Jr’s claims about vaccines have been repeatedly debunked, yet he continues to gaslight people and lie that he’s not anti-vaccine.
Here’s something you’ll NEVER hear from a charlatan: “Correcting my post from last week…”
🚩 Is there any conflict of interest or source for bias?
It should be obvious, but if someone is sponsored by or selling you a product, even if it’s a mainstream drug, you should be pretty darn skeptical of what they have to say. Not all industry-sponsored research is bad or wrong, but I would look hard for independent verification of any data or claims. And if what they’re selling is some kind of miracle cure that sounds too good to be true? It almost certainly is.
Besides directly selling a product, many of the people who traffic in pseudoscience misinformation get lucrative book deals, speaking gigs, or ad revenue catering to alternative audiences that want to hear something different than mainstream medical advice. I would put people like Vinay Prasad in this group: He has gone from being a relatively unknown oncologist to a celebrity doctor beloved by the Right, and his media blitz during the COVID era has certainly resulted in a cash windfall. Likewise, people like Dr. Joe Ladapo (the Florida Surgeon General) parlay a contrarian stance like opposing COVID vaccines into political power.
🚩 Oversimplifying
Albert Einstein is often quoted as saying:
Set aside the debate over whether this is a misattribution or simply paraphrasing, those words capture the essential truth that a lot of concepts in biology, chemistry, and physics are complex, and at a certain point, over-simplifying them erases critical facts or nuance. Beware people who try to make complicated medical issues sound like something a kindergartener could grasp.
🚩 Are they transparent about uncertainties and adverse effects?
Medical professionals and health writers who are operating in good faith are going to give you the good, bad, and the ugly. Most treatments that can relieve sickness also have the potential for adverse effects, and people shouldn’t sugarcoat or downplay those facts.
Likewise, if there are areas of legitimate doubt or uncertainty, a trustworthy resource will call out when we don’t have enough evidence and they are basing their advice on assumptions or extrapolations. People who are not on the level will always claim complete certainty.
At the same time…
🚩 Do they keep saying they’re “just asking questions”?
What’s wrong with asking questions? When it’s done in good faith—nothing! Challenging the data is critical to the scientific method. However, sowing doubt about everything is a well-worn disinformation tactic used by lobbyists to obscure the evidence for everything from the link between smoking and cancer to fossil fuels and climate change. The goal is not to persuade you to adopt their views, rather they want to make you so confused and frustrated you give up even trying to find the truth. People like Joe Rogan and RFK Jr notoriously deploy this move, as do people who constantly demand scientists debate them; they know that they can spew a bunch of rapid fire BS faster than a flustered researcher can debunk them.
Remember: If someone is “just asking questions” that have already been rebutted numerous times before they are not actually interested in the answer.
🚩 Do they write in an inflammatory manner?
You can make anything sound scary. Did you know that 100% of bottles of water in the US contain an acid called dihydrogen monoxide? And that in high enough quantities it can be fatal?!
Well yeah, it’s called H2O. And if you drink way too much you’ll get sick from nasty electrolyte and water balance shifts; getting even a modest amount of H2O into your lungs is an effective way to die by drowning. And yes, H2O is very slightly acidic when it dissociates in physiologic fluids, as are many vitamins and other compounds necessary for life (like aLL NaTuRaL Vitamin C, aka ascorbic acid).
Framing common biological compounds in unfamiliar technical terms to make them sound scary is a common trick pseudoscience pushers will use, especially to scaremonger about pharmaceuticals and vaccines. A similar tactic is the claim that anything that is “natural” is superior to man-made substances. Not everything natural is healthy, and not everything synthetic or artificial is bad! After all, cyanide and chemotherapy drugs like vincristine are “natural” → they both come from plants.
Finally, is this person writing with empathy? Passion is more than OK, and emotions can run high on contentions subjects, but legitimate medical sources don’t callously disregard the lives of people they don’t agree with. If the author is writing in a dehumanizing manner about one or more groups of people, they are probably just an asshole.
Please note that these Red Flags are not an exhaustive list of every possible warning sign out there, they are simply a starting point. And not every person who displays one of these traits is automatically untrustworthy, but the more Red Flags they display, the more skeptical you should be!
Good Medical Writers on Substack
OK, so we’ve talked a lot about who you shouldn’t be going to for medical advice. Who DO I recommend reading for good quality medical information? Despite the chaos and scrum, there are actually numerous excellent health writers here on Substack. I try to promote them whenever I can through Recommendations, Cross-Posting, Notes, and more. Here are a few that you should check out:
is an MPH/PhD epidemiologist in Texas who writes the excellent public health newsletter Your Local Epidemiologist. She covers lots of timely topics and I have found her particularly helpful for navigating the confusing landscape of respiratory virus vaccines and treatments:
Her article below helpfully explains why we can’t always compare public health recommendations (especially about vaccines) in the US to countries abroad:
is a family medicine doctor in New Jersey who writes about navigating evidence-based medicine recommendations as well as literary essays from the perspective of a physician in the “trenches” of private practice, rather than the ivory tower of an academic teaching hospital:
is an emergency doctor in Boston who also frequently writes for major news outlets, and edits journals such as the Annals of Emergency Medicine. Inside Medicine features interesting takes on medical research as well as podcast interviews with people like Dr. Atul Gawande and :
Enjoyed this, Eric. Another heuristic that I used for information literacy and that applies equally here is the SMELL test. Source, Motivation, Evidence, Logic, Left Out. Lack of credentials, clear profit motive, specious or selective evidence, incoherent reasoning, and conveniently omitted counterfactuals would all line up with your red flags, yes?
This is one of the best posts I’ve ever read on Substack.
First and foremost, it is a well-informed and comprehensive guide to spotting bad medical information on line, and on Substack in particular.
Thanks for the shoutout, and for calling out Vinay Prasad and others!
Restacking with glee :)