# Is Autism caused by Tylenol? **URL:** \ **Category:** Factual Questions\ **Created:** [April 23, 2018, 2:11am UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932 "2018-04-23T02:11:55Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [April 24, 2018, 2:22pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/61 "2018-04-24T14:22:52Z")
> [@electronbee](#): > > So, guys, the OP topic was “does Tylenol cause autism”. Before we go off the side rails on a much more sensitive debate, we should concur that Tylenol does not cause autism. That was established in the first dozen posts. How many times does it have to be said? ---
**Author:** ![IvoryTowerDenizen](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ivorytowerdenizen/32/17937_2.png) [@IvoryTowerDenizen](https://boards.straightdope.com/u/IvoryTowerDenizen)\ **Post date:** [April 24, 2018, 2:35pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/62 "2018-04-24T14:35:12Z")
> [@DavidwithanR](#): > > There’s a reason this thread is about autism, and not about colds - people are spreading fear purely for the sake of spreading fear and watching it grow. > > Autism is not a scary monster. Autism is not a parent’s worst nightmare, nor anywhere close - unless people are just having really boring nightmares these days. Autistic people are weird - well, so what? Grow up. That’s a big oversimplification. I have two close friends- one has an autistic child that will probably go to college and live a nice independent life, albeit a bit quirky one. The other, well, his younger sister will probably be caring for him his entire life (after the parents cannot). He is barely verbal, has no life skills, and is aggressive. Both had early intervention and love and resources. You just don’t know ahead of time. ---
**Author:** ![doubleminus](https://avatars.discourse-cdn.com/v4/letter/d/5daacb/32.png) [@doubleminus](https://boards.straightdope.com/u/doubleminus)\ **Post date:** [April 24, 2018, 3:33pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/63 "2018-04-24T15:33:32Z")
> [@TroutMan](#): > > That was established in the first dozen posts. How many times does it have to be said? Hold your horses a bit. There is evidence that acetaminophen during pregnancy could be neurotoxic, and a recent metastudy showed 20% increase in Autistic Spectrum Disorders, and 30% in ADHD in children exposed to acetaminophen in utero. Now, these are observational studies, but raise serious suspicion. Google “acetaminophen ASD” Acetaminophen is a nasty drug and the main reason for hepatic failure. There are hundreds of suicide deaths yearly with OTC Tylenol, an extremely painful and gruesome way to die. And hundreds of accidental deaths. Over 30,000 hospitalizations/year which result in a death rate of only 1%, just because the standard of care is so good. While a useful substance, it should have never been allowed OTC status. Google “acetaminophen deaths” Of course, all this has nothing to do with vaccines. Sorry for not posting links, I’m on a smartphone and could not figure out how to do it in the new UI. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [April 24, 2018, 5:57pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/64 "2018-04-24T17:57:53Z")
> [@DavidwithanR](#): > > There’s a reason this thread is about autism, and not about colds - people are spreading fear purely for the sake of spreading fear and watching it grow. > > Autism is not a scary monster. Autism is not a parent’s worst nightmare, nor anywhere close - unless people are just having really boring nightmares these days. Autistic people are weird - well, so what? Grow up. But it is incurable, so that is scary. Hell, even herpes is scary to many, even tho it is mostly harmless and mostly everyone has it- as it is incurable. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [April 24, 2018, 5:59pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/65 "2018-04-24T17:59:12Z")
> [@Novelty\_Bobble](#): > > The one question that should be settled before trying to establish a causal link is…Is the incidence of Autism in Cuba actually lower than in the USA? Seeing as it is a broad spectrum disorder and subject to variations in diagnosis you would have to be certain that you were comparing like with like before moving to consider why that may be. > > . I would suspect that the incidence of _reported_ autism is indeed lower, just like it is in most third world nations. Borderline cases are not reported. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [April 24, 2018, 6:07pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/66 "2018-04-24T18:07:03Z")
> [@doubleminus](#): > > Hold your horses a bit. There is evidence that acetaminophen during pregnancy could be neurotoxic, and a recent metastudy showed 20% increase in Autistic Spectrum Disorders, and 30% in ADHD in children exposed to acetaminophen in utero. Now, these are observational studies, but raise serious suspicion. The [authors of the analysis](http://www.jpost.com/HEALTH-SCIENCE/Acetaminophen-use-during-pregnancy-linked-to-increased-ASD-and-ADHD-risk-552569) you cite note that there are significant limitations to the studies they reviewed, and that pain and fever during pregnancy (which led to the use of acetaminophen) could potentially have had detrimental effects on the fetus themselves. Moreover, the review doesn’t support antivaxers’ claims that giving acetaminophen/Tylenol to kids after vaccination causes autism. The review looked at long-term administration of the drug during pregnancy, which is a considerably different proposition. Interesting statement from a scientist involved in a separate review that (once again) debunked claims of a vaccine-autism connection: _“As an epidemiologist I believe the data that is presented in this meta-analysis. However, as a parent of three children I have some understanding of the fears associated with reactions and effects of vaccines. My first two children have had febrile seizures after routine vaccinations, one of them a serious event. These events did not stop me from vaccinating my third child, however, I did take some proactive measures to reduce the risk of similar adverse effects. I vaccinated my child in the morning so that we were aware if any early adverse reaction during the day and I also gave my child a dose of paracetamol 30 min before the vaccination was given to reduce any fever that might develop after the injection.”_ > **[New Meta-analysis Confirms: No Association Between Autism and Vaccines |...](https://www.autismspeaks.org/science-news/no-association-between-autism-vaccines)** > > Is there a connection between autism and vaccines? Studies reaffirm that vaccines don't cause autism and that some immunizations can decrease autism risk. We know that high enough fevers can be neurologically damaging. Parents need to think about relative risks - i.e. subjecting a child to potentially high fevers over the course of a vaccine-preventable disease, as opposed to the possibility of a transient temperature elevation post-vaccination. ---
**Author:** ![doubleminus](https://avatars.discourse-cdn.com/v4/letter/d/5daacb/32.png) [@doubleminus](https://boards.straightdope.com/u/doubleminus)\ **Post date:** [April 24, 2018, 8:45pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/67 "2018-04-24T20:45:34Z")
I never claimed a vaccine/Tylenol/autism link, which is ridiculous. I only claimed that there _could_ be some neurotoxicity for acetaminophen during pregnancy. Since this is a grand-grand-grandfathered drug, I suspect there were no trials for that. My _personal_ view is that this is another case of correlation but not causation. However, I am less than happy that one can buy a pound of pills at one go, OTC, and it’s useful to instill a healthy dose of fear towards this drug, outside of hospital settings. Sent from my Mi A1 using Tapatalk ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [April 24, 2018, 9:08pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/68 "2018-04-24T21:08:01Z")
> [@doubleminus](#): > > …it’s useful to instill a healthy dose of fear towards this drug, outside of hospital settings. If backed by sufficient evidence, “fear” (or at least caution) would be advisable. In this setting “fear” of acetominophen seems a bit over the top. It’s [challenging](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4303056/) (ethically and otherwise) to design controlled studies of drugs in pregnant women. Given [the lack](https://www.aafp.org/afp/2014/1015/p548.html) of over-the-counter drugs demonstrated safe via controlled trials in pregnant women, one might choose to avoid all of them. Or not get sick in the first place. :dubious: ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [April 24, 2018, 9:10pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/69 "2018-04-24T21:10:09Z")
> [@doubleminus](#): > > … it’s useful to instill a healthy dose of fear towards this drug, outside of hospital settings. Suggesting an association between autism and unrelated concerns about acetaminophen is not healthy. Maybe it was unintentional, but coming into a thread about autism with “I’m not saying there’s any link to autism, but look at all these other ways acetaminophen is bad” and then pretending it was only done to educate is a little duplicitous. If you think it might be connected to autism, say it. If not, there’s no reason to bring it up here. ---
**Author:** ![doubleminus](https://avatars.discourse-cdn.com/v4/letter/d/5daacb/32.png) [@doubleminus](https://boards.straightdope.com/u/doubleminus)\ **Post date:** [April 24, 2018, 10:10pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/70 "2018-04-24T22:10:54Z")
**Jackmanii** I don’t see why randomizing between Acetaminophen, Ibuprofen and maybe Naproxen and Aspirin during pregnancy would be problematic or unethical. **TroutMan** I clearly stated in my first post in this thread that there is a [serious metastudy](https://academic.oup.com/aje/advance-article/doi/10.1093/aje/kwy086/4980325#) showing a suspicion of a relationship between long term acetaminophen use in pregnancy and ASD and ADHD. If interested, PM me and I will send you the full text. The authors carefully qualify this finding. I also said that I \*\* personally\*\* believe that this is not a causation link. In addition, and completely unrelated to autism, I also claimed that Acetaminophen is a dangerous OTC analgesic. It has a dangerously low [Therapeutic Index](https://en.m.wikipedia.org/wiki/Therapeutic_index) of 2.5-3, and indeed causes a lot of intentional and unintentional life-endangering overdoses. You are, of course, entitled to your opinion that this should have not been posted in this thread and I can even understand you. However implying any weaseling or ulterior motives is somewhat insulting. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 24, 2018, 10:18pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/71 "2018-04-24T22:18:56Z")
While many drugs are unstudied for safety in pregnant women, acetaminophen in particular is known to be iffy even for adults. I think that avoiding it while pregnant is a perfectly reasonable precaution. ---
**Author:** ![Guinastasia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guinastasia/32/5751_2.png) [@Guinastasia](https://boards.straightdope.com/u/Guinastasia)\ **Post date:** [April 24, 2018, 10:23pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/72 "2018-04-24T22:23:38Z")
> [@DavidwithanR](#): > > Autism is not a scary monster. Autism is not a parent’s worst nightmare, nor anywhere close - unless people are just having really boring nightmares these days. Autistic people are weird - well, so what? Grow up. Autism is a spectrum disease. It can indeed be a “[nightmare](http://blog.cleveland.com/metro/2009/12/kent_state_professor_trudy_ste.html)”. In severe cases, autistic people will engage in [self-harm](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3990505/), are non-verbal, have hours-long tantrums, etc. Fortunately, most cases of autism aren’t like this, but yeah, it happens. ---
**Author:** ![Dr\_Paprika](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr_paprika/32/3042_2.png) [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)\ **Post date:** [April 25, 2018, 2:56am UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/73 "2018-04-25T02:56:49Z")
I would guess roughly half of pregnant women use acetaminophen at some point, which is given a class B safety rating. It is thought to be safer than NSAIDs like ibuprofen and naproxen which can increase bleeding risk and are given a safety rating of C. The case-control studies showing associations between Tylenol, ASD, ADHD and other disorders have some problems. There may be links between maternal fever in pregnancy and behavioural disorders. ---
**Author:** ![Nava](https://avatars.discourse-cdn.com/v4/letter/n/da6949/32.png) [@Nava](https://boards.straightdope.com/u/Nava)\ **Post date:** [April 25, 2018, 11:54am UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/74 "2018-04-25T11:54:25Z")
> [@Thudlow\_Boink](#): > > Said “bad rap” being its implication in Reye’s Syndrome? No: it got a reputation of being “bad for the stomach”. The immense majority of people who’ll tell you aspirin is “bad for the stomach” have no idea Reye’s exists (I do, a childhood friend of mine died of it). ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [April 25, 2018, 12:07pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/75 "2018-04-25T12:07:45Z")
It needs to be (re)emphasized that Tylenol has a very good record of safety, unless people exceed the recommended dose (usually by not watching how much they consume in OTC cold remedies plus taking acetominophen), simultaneously drink alcohol (increasing the potential for liver toxicity) or have significant liver problems in the first place. > **[Acetaminophen safety: Be cautious but not afraid - Harvard Health](https://www.health.harvard.edu/pain/acetaminophen-safety-be-cautious-but-not-afraid)** > > The maximum daily dose of acetaminophen for a healthy adult who weighs at least 150 pounds is 4,000 milligrams (mg). However, in some people, taking the maximum daily dose for extended periods can ... [It should not be assumed](https://health.clevelandclinic.org/is-acetaminophen-more-dangerous-than-ibuprofen/) that NSAIDS are safer. ---
**Author:** ![Skara\_Brae](https://avatars.discourse-cdn.com/v4/letter/s/f0a364/32.png) [@Skara\_Brae](https://boards.straightdope.com/u/Skara_Brae)\ **Post date:** [April 25, 2018, 12:59pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/76 "2018-04-25T12:59:34Z")
> [@Chronos](#): > > While many drugs are unstudied for safety in pregnant women, acetaminophen in particular is known to be iffy even for adults. I think that avoiding it while pregnant is a perfectly reasonable precaution. What do you mean “iffy”? When I was pregnant, Tylenol was the only painkiller I was allowed to take. ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [April 25, 2018, 2:01pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/77 "2018-04-25T14:01:22Z")
> [@doubleminus](#): > > **Jackmanii** I don’t see why randomizing between Acetaminophen, Ibuprofen and maybe Naproxen and Aspirin during pregnancy would be problematic or unethical. Because there are serious and proved risks of any drug that is a blood thinner during pregnancy? they can cause separation of the placenta from the uterine wall, which is death for the fetus, and can cause serious bleeding in the mother that is sometimes resolved only by a hysterectomy. ETA: I remember the list of safe and non-safe drugs during pregnancy. Aspirin, ibuprofen and naproxen were all absolute "No"s, while codeine was OK if prescribed by a doctor who was aware that I was pregnant. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 25, 2018, 2:12pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/78 "2018-04-25T14:12:21Z")
Among healthy adults, Tylenol has a very low therapeutic index (the ratio of a dangerous dose to a typical dose). What’s the dangerous dose for a baby, or for a fetus? If it’s even a little bit lower than for a healthy adult, then the fetus could be getting a dangerous dose even with normal usage. ---
**Author:** ![sbunny8](https://avatars.discourse-cdn.com/v4/letter/s/c77e96/32.png) [@sbunny8](https://boards.straightdope.com/u/sbunny8)\ **Post date:** [April 25, 2018, 2:41pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/79 "2018-04-25T14:41:36Z")
> [@Jackmannii](#): > > It needs to be (re)emphasized that Tylenol has a very good record of safety, unless people exceed the recommended dose (usually by not watching how much they consume in OTC cold remedies plus taking acetominophen), simultaneously drink alcohol (increasing the potential for liver toxicity) or have significant liver problems in the first place. The criticism that I’ve heard is that there’s a surprisingly small margin between how much Acetaminophen you have to take to handle your pain and how much Acetaminophen can kill you. Tylenol recently [lowered the maximum recommended daily dose](https://www.tylenol.com/safety-dosing/usage/dosage-for-adults) from 4,000 mg to 3,000 mg. According to [this website](https://wikem.org/wiki/Acetaminophen_toxicity), 10,000 mg in a single day, or 6,000 mg each day for just two days in a row, is considered a “toxic dose”. Extra Strength Tylenol is 500 mg each. That means 24 pills in 96 hours is within the recommended dosage, but 24 pills in 48 hours warrants a trip to the emergency room. ---
**Author:** ![Ravenman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ravenman/32/2929_2.png) [@Ravenman](https://boards.straightdope.com/u/Ravenman)\ **Post date:** [April 25, 2018, 3:23pm UTC](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932/80 "2018-04-25T15:23:12Z")
> [@Chronos](#): > > Among healthy adults, Tylenol has a very low therapeutic index (the ratio of a dangerous dose to a typical dose). What’s the dangerous dose for a baby, or for a fetus? If it’s even a little bit lower than for a healthy adult, then the fetus could be getting a dangerous dose even with normal usage. A couple days ago I found a CDC study that showed that the number of annual deaths attributed to acetaminophen was roughly ten times lower than the number of deaths attributed to aspirin and other NSAIDs, apparently due to GI bleeding. I don’t know anything about this field, but I’m having trouble squaring these issues. I don’t know jack about the safety of Tylenol, but if aspirin and Advil are responsible for ten times more deaths, I’m not sure how I can conclude that Tylenol is pretty dangerous. Here’s the study, it is cached because the CDC website doesn’t seem to be working at the moment. Unfortunately the graphics showing the mortality data don’t come up on this version. [https://webcache.googleusercontent.com/search?q=cache:8InPMB26\_ZgJ:https://www.fda.gov/ohrms/dockets/ac/02/briefing/3882B2\_02\_McNeil-NSAID.htm+&cd=1&hl=en&ct=clnk&gl=us](https://webcache.googleusercontent.com/search?q=cache:8InPMB26_ZgJ:https://www.fda.gov/ohrms/dockets/ac/02/briefing/3882B2_02_McNeil-NSAID.htm+&cd=1&hl=en&ct=clnk&gl=us) [Previous page](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932.md?page=3) [Next page](https://boards.straightdope.com/t/is-autism-caused-by-tylenol/812932.md?page=5)