The title says it all. Tylenol does not cause Autism. Autism is a highly heritable congenital neurological condition, that for some can be mildly to significantly disabling. As a part of the current USA Federal Government’s list of interesting choices, President Donald Trump has instructed the FDA to warn doctors to advise against using Tylenol (acetaminophen USA, paracetamol Au) for children and pregnant women, due to concern that this medication ’causes’ Autism. To be clear, it does not *. Australia’s TGA has put out a press statement to this effect.
The most unfortunate thing about this entire fiasco is that for cheap political points, the Trump administration is promoting increased fear about Autism, ADHD and other neurological conditions, while at the same time making it harder for pregnant people to feel safe to take medications that have excellent evidence at being effective for many people with almost no risk when taken as recommended by the manufacturer and medical doctors.
* with 150 years of pregnant people taking paracetamol, plus a massive robust study, no higher or lower instance of Autism / ADHD etc is demonstrated vs people who don’t. — See Can we truly know that paracetamol is safe? below for more.
These are all the same chemical:
- Tylanol
- Paracetamol
- Acetaminophin
- Panadol
TLDR: There was some enquiry over the last few decades about whether paracetamol might cause neurological conditions like Autism, ADHD etc. Some correlations were found that led credence to the need to investigate. An excellent and robust investigation (JAMA, 2024) plus almost 150 years of medical records shows that paracetamol / tylanol does not cause any specific dirth defects or neurological conditions. That is Paracetamol / Tylenol does not cause Autism.
- Australia’s Chief Medical Officer and the TGA join with other global medicines regulators, leading clinicians and scientists worldwide in rejecting claims regarding the use of paracetamol in pregnancy, and the subsequent risk of development of ADHD or autism in children.
- Robust scientific evidence shows no causal link between the use of paracetamol in pregnancy and autism or ADHD, with several large and reliable studies directly contradicting these claims.
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Politics: Truth is responsible (and boring), sensational isn’t
Back in April 2025, Robert F. Kennedy Jr. pledged to find the cause of Autism ‘by September’. As is often the case for RFK, he completely ignored what many fields of scientific medical enquiry have done and are doing, and thought he could uncover what multiple decades of quality research have failed to do in 6 months. If I asked you, a lay person, to discover the truth behind a problem in a very complex field (human biology) that tens of thousands of very qualified researches had been dedicating over 5 decades of their life to doing, I suspect you would estimate it would take you more than 6 months to find what they did not. Unless you already thought you had an answer.
Robert F. Kennedy Jr. had stated a few times his belief that acetaminophen (paracetamol) was a good candidate for a cause for Autism prior to September 2025, which did allowed Science Communicators to get a bit ahead of the game and review the existing body of scientific literature on this likely claim that JFK was going to make – which he and Trump have now made. An excellent exploration of this possible link was done by Science Versus (Podcast), “Does Tylenol Cause Autism?“
Effectively, we have excellent, robust evidence that there Tylenol / Paracetamol does not cause Autism, ADHD etc (see below for What does the data show?)
If this is true, why is Trump and Kennedy Jr. claiming it does? This is most likely because Kennedy Jr. needs to come up with something to meet his April 2025 pledge of revealing the cause for Autism, and it is now September 2025. We scientifically know what causes Autism – genetics. Because Autism is a congenital hereditary neurological condition (current data indicates you are over 80% likely to inherit Autism, ADHD etc). RFK does not like this answer and wants something else to blame. Kennedy Jr. is on record in stating belief in the thoroughly debunked lie about vaccines causing Autism and many other similarly debunked false leads to the erroneous quest for some external agent. (To be fair to many of the scientists pursuing these, the hereditary link wasn’t robust back then).
Keep in mind that both Trump and Kennedy have rarely used consultation with experts to inform the public about the current consensus of scientific knowledge. They tend to go for sensational over correct.
Science: What does the data show?
Here is a quick summary of the Paracetamol causing Autism query:
- Paracetamol (Tylenol) is a medication that relieves pain. It was created in 1878, just shy of 150 years ago. Part of this is done by being an endocrine disruptor. Autism is a congenital (you are born with it) neurological condition. Lines of enquiry into how Paracetamol might affect a fetus began over a decade ago.
- A claim was made by the “Birth Injury Center” that a study in JAMA Psychiatry in 2020 “considered a cohort of 996 mother-infant pairs. It found that Tylenol exposure during gestation was associated with significantly increased risks of childhood attention-deficit hyperactivity disorder, or ADHD, and autism spectrum disorder (ASD).” It also claimed that the FDA (USA Food and Drug Administration) “The U.S. Food and Drug Administration has also expressed concern about the possible link between Tylenol and autism” and conveniently left a link to the article (addressed below).
- The article in JAMA, 2019, cited by Birth Injury Center above, considered a pool of 3163 mother/infant pairs, found 996 birthing cords with sufficient blood to test the plasma for the presence of paracetamol.
- It found that the infants diagnosed with a neurological condition (Autism, ADHD, Developmental Disorder or another ND) had a higher correlation of paracetamol than the infants who were neurotypical.
- The article attempted to negate confounding variables, such as socioeconomic status, age etc.
- They concluded that there was a statistically higher amount of paracetamol detected in the birthing cords of infants later diagnosed with a neurological condition, and further, that there was a dose response – the more that the mother took, the higher the chances of that child also being diagnosed with a neurological condition. “The findings from this study contribute knowledge to ongoing research regarding the potential adverse neurodevelopmental consequences of perinatal acetaminophen exposure.”
- The FDA article, 2015, says “The U.S. Food and Drug Administration (FDA) is aware of and understands the concerns arising from recent reports questioning the safety of prescription and over-the-counter (OTC) pain medicines when used during pregnancy. As a result, we evaluated research studies published in the medical literature and determined they are too limited to make any recommendations based on these studies at this time. Because of this uncertainty, the use of pain medicines during pregnancy should be carefully considered. We urge pregnant women to always discuss all medicines with their health care professionals before using them.”
- What this means is: Some people are worried, but so far there is no data to support these claims (the medication was made in 1878 and has been used since with no indication of concern), so no recommendation is issued to stop the medication.
- However, there is no proof it is safe either, other than over 150 years of use with no real indication of harm.
- So please talk to someone who has good medical knowledge about the medications you are using and lean on their expertise – like a medical doctor.
- What it doesn’t say is “we are worried too, stop using it”.
- The article in JAMA, 2019, cited by Birth Injury Center above, considered a pool of 3163 mother/infant pairs, found 996 birthing cords with sufficient blood to test the plasma for the presence of paracetamol.
- Correlation does not mean Causation
- JAMA published “Acetaminophen Use During Pregnancy and Children’s Risk of Autism, ADHD, and Intellectual Disability”, 2024, where the authors used the excellent database from Sweden, where all health records are available for examination. They looked at 2,480,797 children born between 1995 to 2021. They could fairly accurately correlate the use of paracetamol used by pregnant parents based on who was prescribed paracetamol, bolstered by parents who admitted to the use of paracetamol even if not prescribed. In this case, they were able to compare parents who had given birth to at least 2 children, where any child not exposed to paracetamol was the control for a sibling who was exposed. This negates hereditary causes.
- Conclusion: “Acetaminophen use during pregnancy was not associated with children’s risk of autism, ADHD, or intellectual disability in sibling control analyses. This suggests that associations observed in other models may have been attributable to familial confounding.”
- What does this mean?
- It means that since we already know that Autism is hereditary. That is, autistic parents have autistic children. As is ADHD, Developmental Delay etc.
- We also know that pregnant Autistic people are more prone to pain and are likely to use pain relief to help with that. As are ADHD, Developmental Delay etc.
- People in pain are more likely to use paracetamol than people who are not.
- The correlation of paracetamol found in the birthing cords in the study above (and similar types of studies) ignored the fact that the parent has a similar condition to what the child was diagnosed with, and thus more likely to use paracetamol – they failed to exclude that vital confounding factor.
- This study of 2,480,797 well documented children that excludes the confounding factor of neurovigerent parents and high use of pain relief far outweighs the other studies that noted a correlation without causation and did not factor in hereditary conditions.
- JAMA published “Acetaminophen Use During Pregnancy and Children’s Risk of Autism, ADHD, and Intellectual Disability”, 2024, where the authors used the excellent database from Sweden, where all health records are available for examination. They looked at 2,480,797 children born between 1995 to 2021. They could fairly accurately correlate the use of paracetamol used by pregnant parents based on who was prescribed paracetamol, bolstered by parents who admitted to the use of paracetamol even if not prescribed. In this case, they were able to compare parents who had given birth to at least 2 children, where any child not exposed to paracetamol was the control for a sibling who was exposed. This negates hereditary causes.
It is important to note, this is a very brief summary. The amount of research actually done is far more extensive than this – these are just the highlights to get the jist.
Risk: Can we truly know that paracetamol is safe?
In science, there is no proof of truth, there is only approaching truth or proof of false. It is possible that future research may change our opinion about paracetamol, but that is unlikely due to Sagn’s aphorism.
“Extraordinary claims require extraordinary evidence”, Carl Sagon
Not all evidence is equal, poor research and bad studies are given a low value, robust large studies are given a high value. To outweight the current evidence that paracetamol the suspected link to Autism etc is false would require extraordinary high quality evidence.
What we have here is:
- A medication that has been used by various people for 150 years with no indication in all of that time of any noticeable adverse effects to fetuses when used by pregnant people,
- Had a statistical bump when considering the possibility of more subtle consequence like Autism, ADHD etc,
- When the people doing those studies did not consider the known strong hereditary nature of these conditions,
- Due to missing this important factor, they were concerned that correlation (two things happening at the same time) may be causation (one made the other happen),
- The researches speculation into mechanisms to investigate was confused for evidence of a mechanism of causation,
- When hereditary was factored in, the correlation evaporated
- Showing that you are no more at risk of Autism, ADHD etc using or not using paracetamol.
That is about as close as we can show the scientific ‘truth’ is “paracetamol / tylenol does not cause Autism, ADHD etc”.