UPDATED MARK HYMAN BLOGS
Blog 1: Correcting the Record
It’s been so incredible to see growing numbers of Americans feeling empowered to take control of their own health in recent years. I’m honored that many have found my books and commentary to be helpful — everyone is welcome in this movement toward healthier living.
Because of my early advocacy for ending chronic disease and transforming our food and agricultural system, there’s been a lot of attention paid to my background and views. Many people understand our work and celebrate it, and for that I’m grateful. But unfortunately there’s a small group who mischaracterize or tell flat-out falsehoods about what I believe.
Rather than responding to isolated soundbites, I wanted to answer some of the most common questions directly.
Is your work as a physician impacted by politics?
People often ask whether politics influences my work as a physician. The answer is no.
Throughout my career, I’ve worked with policymakers, scientists, entrepreneurs, and healthcare leaders from across the political spectrum. If you’re committed to improving the health of our nation—whether that’s through better nutrition, addressing the root causes of chronic disease, reducing environmental toxin exposure, or reimagining our healthcare system—you inevitably collaborate with people who hold a wide range of political beliefs.
Collaboration is not the same as ideological alignment. Meaningful change requires engaging with whoever has the ability to move policy forward, regardless of which party is in power.
My responsibility has always been to my patients and to the science—not to politics. I’ve spent my career asking difficult questions, evaluating evidence with an open mind, and following that evidence wherever it leads. My views are shaped by data, clinical experience, and a commitment to improving human health, not by any political ideology.
What is your stance on Tylenol?
Acetaminophen is primarily metabolized in the liver through glucuronidation and sulfation pathways. A small fraction is metabolized via cytochrome P450 enzymes, particularly CYP2E1, into a reactive intermediate called NAPQI.
NAPQI is toxic. Under normal circumstances, it is rapidly neutralized by conjugation with glutathione, the body's primary intracellular antioxidant.
So the statement that acetaminophen can deplete glutathione is biochemically accurate, particularly in overdose or in susceptible individuals. The nuance is that in healthy individuals using recommended doses, the liver is usually well-equipped to handle this metabolism safely.
Where I add context, and this is often what gets shortened in media summaries, is that modern populations have high rates of metabolic dysfunction, alcohol use, micronutrient insufficiency, and environmental toxic burden, all of which can influence hepatic detoxification capacity.
That does not mean Tylenol should be avoided universally. It means dosing, duration, liver health, alcohol intake, and overall metabolic status matter.
My goal is not to demonize medications. It is to understand how they interact with biology, and to help patients make informed decisions based on their individual health context.
Should pregnant women take Tylenol?
My recommendation is simple: treat significant fever and pain when treatment is needed. Use the lowest effective dose for the shortest period necessary, and work with your healthcare provider to determine what is appropriate for your individual situation.
A 2024 study from Sweden followed nearly 2.5 million children. At first, researchers saw small links between moms taking acetaminophen during pregnancy and children later diagnosed with ADHD or autism.
But when they compared siblings, where a mother took Tylenol during one pregnancy but not another, the link disappeared. The exposed sibling was no more likely to be diagnosed with autism than the unexposed sibling.
One reason this question is difficult to study is that pregnant women often take Tylenol for fever, infection, migraines, and aches and pains, especially when those symptoms interfere with sleep.
Fever and infection themselves have been linked to developmental issues in children. That makes it difficult to know whether any observed risk comes from the medication or from the condition the medication was being used to treat.
We also don't have randomized controlled trials, the kind of studies that can prove cause and effect, because it would not be ethical to conduct those experiments in pregnant women and their developing babies.
What we do know is that uncontrolled fever or infection during pregnancy can carry risks of their own. Acetaminophen is often used because it is generally considered the safest option for reducing fever and managing pain during pregnancy.
Other pain relievers, such as ibuprofen (Advil) and naproxen (Aleve), carry clearer risks later in pregnancy, including effects on a baby's kidneys, amniotic fluid levels, and blood flow through the heart before birth.
Are you anti-vaccine?
Vaccines are one of the most polarizing subjects in modern medicine, and polarization has a way of crowding out nuance. I think it’s important to make my position clear.
I believe vaccines have saved millions of lives and dramatically reduced the burden of infectious disease. That is one of the great achievements of modern medicine. I am not anti-vaccine.
At the same time, I believe that good public health depends on more than scientific innovation—it depends on public trust. Trust isn’t built by dismissing questions or concerns. It’s built through transparency, open dialogue, and a willingness to follow the evidence wherever it leads. People are far more likely to make informed decisions when they feel heard and are given clear, honest information.
Vaccines are not a single intervention. They differ in their design, mechanisms, safety profiles, effectiveness across populations, and the contexts in which they’re used. Like every medical intervention, they deserve ongoing evaluation as new evidence emerges.
My perspective has been consistent throughout my career:
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Follow the best available evidence.
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Continue rigorous research into long-term safety and effectiveness.
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Be transparent about both benefits and risks, including rare adverse events.
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Respect informed consent and foster trust rather than relying on coercion whenever possible.
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Recognize that vaccines are one part of a broader approach to health, which also includes optimizing metabolic health, nutrition, immune resilience, and the underlying drivers of chronic disease.
Science is a process, not a fixed destination. Our understanding evolves as better data become available, and our recommendations should evolve with it. That’s not a rejection of vaccines—it’s a commitment to scientific integrity, transparency, and earning the public’s trust.
What are your views on COVID vaccines?
My perspective on COVID vaccines has always been rooted in the same principles that guide my approach to all of medicine: follow the evidence, weigh risks and benefits carefully, and recognize that medical decisions are rarely one-size-fits-all.
One of the clearest lessons from the pandemic was that underlying health matters. People with obesity, diabetes, cardiovascular disease, and other chronic conditions were at significantly greater risk of severe illness and death. For those at higher risk, vaccination represented an important tool for reducing that risk.
At the same time, risk is not uniform across the population. A healthy young adult faces a very different risk profile than an older adult with multiple chronic conditions. That’s why I believe conversations about vaccination should always consider an individual’s age, health status, medical history, and personal risk—not just broad population averages.
Public health recommendations are designed to protect populations, while clinical medicine is about caring for individuals. Those perspectives often align, but they are not always identical. My goal has always been to help people understand the evidence, have honest conversations about benefits and risks, and make informed decisions in partnership with their healthcare providers.
Do vaccines cause autism
No.
The weight of the evidence does not support the claim that vaccines directly cause autism.
Large epidemiologic studies have not demonstrated a causal link between vaccines and autism.
Unfortunately, this is one area where my views have really been mischaracterized. When I spoke about the precautionary principle in the past, the argument was not that thimerosal was proven harmful in vaccines at existing doses. The argument was that when there is public fear around an ingredient, especially one containing mercury, and when alternatives exist, removing it could restore confidence without compromising immunization programs.
What do you think are the root causes of autism?
Autism is a complex neurodevelopmental condition with diverse genetic, environmental, immune, and metabolic contributors.
There is no credible evidence that cod liver oil "treats autism," and I have never suggested otherwise.
What I have discussed in clinical and educational contexts is that some children on the autism spectrum may have underlying nutritional deficiencies, mitochondrial dysfunction, altered fatty-acid metabolism, gut-immune dysregulation, elevated toxic burden or elevated inflammatory markers.
Omega-3 fatty acids play structural and signaling roles in neuronal membranes, synaptic plasticity, and inflammatory regulation. There is limited and mixed evidence that omega-3 supplementation may modestly support certain behavioral or attentional symptoms in some individuals. Not cure autism. Not reverse autism. And certainly not as a standalone therapy.
That distinction matters.
What about thimerosal?
Thimerosal is a preservative that contains ethylmercury. It was used in some multidose vaccine vials to prevent bacterial contamination.
Ethylmercury is metabolized and cleared from the body more rapidly than methylmercury, the type found in certain fish, and large epidemiologic studies have not demonstrated a causal link between thimerosal-containing vaccines and autism.
By 2001, thimerosal was removed from nearly all routine childhood vaccines in the United States as a precautionary measure.
Today, it is not present in standard pediatric vaccine schedules.
When I spoke about the precautionary principle, the argument was not that thimerosal was proven harmful in vaccines at existing doses. The argument was that when there is public fear around an ingredient that is a known neurotoxin and alternatives exist, removing it could restore confidence without compromising immunization programs.
Is the flu shot safe?
Yes. This question often comes up in discussions about thimerosal because some multidose influenza vaccines still contain it, although thimerosal-free flu vaccines are widely available.
It's important to distinguish between concerns about a specific ingredient and concerns about the vaccine itself. Large epidemiologic studies have not demonstrated a causal link between thimerosal-containing vaccines and autism, and thimerosal was removed from nearly all routine childhood vaccines in the United States more than two decades ago.
When I discussed thimerosal in the past, the conversation was centered on the precautionary principle and public trust. It was not a claim that flu vaccines are unsafe or that thimerosal was proven harmful at the doses used in vaccines.
As with any medical intervention, decisions should be based on the current evidence, individual risk factors, and informed discussion with a healthcare provider.
Do you believe in germ theory?
I absolutely believe in germ theory. Pathogens cause disease. Viruses, bacteria, fungi, and parasites have specific mechanisms of infection and injury. That is foundational biology. I trained in medicine. I prescribe antibiotics when appropriate. I supported vaccination strategies for high-risk populations during COVID. I do not deny microbes exist or that they cause illness.
What I have said, and will continue to say, is that the microbe is part of the equation.
There is a long scientific tradition, dating back to Louis Pasteur and Claude Bernard, recognizing that both the pathogen and the host terrain matter. Two people can be exposed to the same virus and have profoundly different outcomes. That is not mysticism; it is immunology, metabolism, and epidemiology.
COVID-19 provided one of the clearest large-scale demonstrations of this principle.
In the United States, the overwhelming majority of severe COVID outcomes occurred in individuals with underlying metabolic disease. CDC analyses showed that over 90% of hospitalized COVID patients had at least one comorbidity, most commonly obesity, hypertension, type 2 diabetes, or cardiovascular disease. Obesity alone was associated with significantly increased risk of hospitalization, ICU admission, and death. Type 2 diabetes markedly increased mortality risk. Metabolic dysfunction was not peripheral; it was central.
That does not mean SARS-CoV-2 did not cause COVID. It means the host metabolic environment strongly influences severity.
Immunometabolism is now a major area of research. Insulin resistance alters innate immune signaling. Chronic inflammation affects cytokine responses. Vitamin D status influences antimicrobial peptide expression. Micronutrient deficiencies impair adaptive immunity. These are not alternative ideas; they are mainstream physiology.
To say “host health matters” is not germ theory denial. It is systems biology.
I do not reject conventional medicine. I use it. I also believe it is incomplete when it ignores terrain.
We can hold two truths at once:
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Pathogens cause disease.
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The resilience of the host meaningfully shapes outcomes.
Blog 2: Why I Sell Supplements
On my website, you may have noticed links to purchase nutritional supplements. I’ve been asked before about why I offer these resources to the public, so I want to set the record straight.
Let me explain for a moment what vitamins and minerals do.
They are not drugs, they do not work like drugs, and they cannot be studied like drugs, which is why you hear so much conflicting information about them in the media. They are, however, essential components of our biology that make every chemical reaction in our body function, including metabolism, energy generation, and calorie burning.
The human body is an extraordinarily complex system where trillions of chemical reactions occur every single day to maintain health and vibrancy. Each reaction requires a catalyst (an enzyme), and each catalyst has a helper or cofactor (coenzyme). Vitamins and minerals are those helpers. Without optimal levels, your biochemistry doesn't run well and, in some cases, doesn't run at all.
There is also a stark difference between nutrient deficiency and optimal levels.
The Recommended Dietary Allowances (RDAs) and Adequate Intakes (AIs) established by health agencies are designed to prevent deficiency diseases in the general population. They provide the minimum amount of each nutrient needed to avoid overt deficiency symptoms. Optimal levels aim to achieve the best possible health outcomes, including enhanced physical performance, cognitive function, disease prevention, and overall well-being.
The challenge is that many people are not getting those optimal levels.
The foods we eat today are highly refined, stripping them of many essential minerals during processing. The food we eat today is about 30% less nutritious than it was in 1940. This is the classic case of being "overfed but undernourished."
At the same time, industrial agriculture has depleted the nutrient density of our food supply. Plants get their nutrients from the soil, and animals get their nutrients from plants. Thus, the more nutrient-depleted the soil is, the fewer nutrients the vegetation growing on it will have.
Even if we eat a completely perfect diet, the increased stress of modern life, combined with a toxic environment, increases our nutritional demands. Toxins and stress deplete our bodies of nutrients, making it harder to get what we need from food alone.
While whole, real food should be the foundation of any healing protocol, modern agricultural practices, long transport and storage times, and soil depletion have reduced the nutrient content of our food. Supplements can provide additional support when nutritional gaps exist.
Because of these problems, for years I've been asked where to buy high-quality supplements. I could see that people were confused about what to take, why, and where to source from.
With such a volume of inbound from my patients and community, I felt it was important to address a critical gap in the supplement market: the need for highly curated, high-potency, and high-bioavailability supplements that are meticulously tested for environmental toxins and ingredient quality.
When I recommended specific ingredients in clinical practice, quality varied widely across the market. Many products contained fillers, poor bioavailability forms, or inadequate dosing. Rather than recommend products I couldn't verify, I helped create formulations that met clinical standards.
This is why I started a supplement store: a highly curated store which my community and peers can trust, knowing the rigor of quality control and attention that our team puts into selecting each product.
We only choose brands that use best-in-class manufacturing practices, are backed by scientific data, and have a proven history of efficacy, potency, bioavailability, and safety. All of our products are third-party tested for active ingredients and contaminants and are free of preservatives, fillers, binders, and common allergens.
I understand the skepticism around anyone who both educates and sells products. That is a fair conversation. My position has always been that if I recommend a protocol in clinical practice, I want clean, transparent, rigorously tested formulations available.
But that does not mean everyone needs supplements, nor does it mean supplements replace foundational lifestyle change.
Food first.
Sleep first.
Movement first.
Stress reduction first.
Supplements are adjuncts.