10/09/2025
Tylenol, Leucovorin and Autism
By now, you will have heard that Health and Human Services (HHS) and the President have stated that Tylenol (acetaminophen) in pregnancy can cause autism, and that leucovorin can help treat it, implying that we are turning the corner on this condition. This is the same President who said that ivermectin and hydroxychloroquine are good for treating COVID (they aren’t), who says that even twenty years ago, when he was a businessman and TV personality, he “understood a lot more than a lot of people who studied [autism],” and who claims to be an expert in science because he had an uncle who taught at MIT.
If you look at the official HHS statement, it is actually reasonably muted and cautious in its claims, but this is not the message people will remember. Instead, they will remember President Trump at his news conference erroneously claiming that taking Tylenol during pregnancy is associated with a ‘greatly increased risk’ of autism. They will also recall Robert Kennedy promising to announce the cause of autism by the end of September, hence folate deficiency.
Let’s start with Tylenol first. I will use this term rather than the generic, to be consistent with President Trump’s claims. One major study has indicated that Tylenol might be a risk factor for autism, while another has not. If it is a cause of autism, it is certainly not a major cause, and not taking it during pregnancy could at best reduce the risk very slightly. That having been said, my advice for pregnant women is unchanged from before, and that is to avoid taking any medicine as much as possible. If you are in pain, try non-medicine approaches such as massage, heat or cold packs, etc. However, if you are suffering, no reputable physician advocates being unable to sleep or eat, or having high fevers, as being beneficial for a fetus, so in these cases it would appear the better option is to take medicine.
President Trump has also said that children should not be taking Tylenol. This is not part of the HHS statement, I am not aware of any studies supporting this, and, like many things he says, it is simply something he made up. Don’t believe it. If your child is feeling badly, and Tylenol can make them better, I have no problem with using it.
President Trump has also said, again without any data to support it, that parents should break up vaccines and get one at a time, making extra trips to do so. He also says parents should give their children separate measles, mumps and German measles vaccines, immunizations that are not available. Following his suggestion, with the current schedule, and assuming we can break up combination vaccines, families would be expected to make 34 visits by fifteen months to be fully immunized, instead of the current 8.
President Trump suggested that the reason doctors advocate for combination vaccines, and multiple vaccines at a time, is to make more money. This is a lie. I advocate for the current schedule because it is in the best interest of the child and family. Less shots means less pain, and less visits means more time for families to do other things. Specifically looking at making money, I will point out the obvious, that doctors make less money, not more, the less patient visits they have.
Moving on to leucovorin. Leucovorin is related to the vitamin folate (vitamin B9), which in turn can be considered interchangeable with folic or folinic acid (synthetic forms of the vitamin). Folic acid has been given routinely to pregnant women for decades now, as it known to prevent some birth defects, so fetal deficiencies are quite rare. Thus, right off the bat, that makes me suspicious of the claim that leucovorin will help most children, although it is theoretically possible that it does something else of which we are unaware.
Some children with autism (not most, and probably not even the majority) do have problems with folate metabolism. That does not mean it is the cause of autism (it could be secondary to other factors), and, more importantly, it does not mean that supplementation will automatically be of benefit.
The following statement is cynical, but also valid. I expect leucovorin to be the biggest breakthrough in the treatment of autism since secretin, or possible auditory integration training, or even ketoconazole, or dimethylglycine, or facilitated communication (FC), or peptides, or casein and gluten-free diets, or hyperbaric oxygen, or chelation therapy. They all had this in common: they were all hailed as breakthroughs at one time, with minimal to no evidence, and none of them panned out. This is only a partial list, by the way.
(I will digress to talk some more about FC, a fascinating bit of autism history, that also provides a cautionary tale. Many children with autism can communicate by pointing to pictures on a communication board, or using a tablet, and this has indeed been a boon. In FC, the approach looks similar, but there is a major difference: it only works if someone (the facilitator) is helping to guide the hand or arm of the autistic person, who otherwise cannot access the device. This took off in the 1980s, for obvious reasons, because, for the first time, some autistic children were telling their parents they loved them. Some were even writing books of poetry, and parents were producing best-sellers about new connections with their children. Large conferences were held where people could see the miraculous results for themselves. News programs gushed over it. The Northern Virgina chapter of the Autism Society of America passed a resolution that FC should be taught in schools. Douglas Biklen, the person most responsible for the movement in this country, was rewarded with the creation of the Facilitated Communication Center at Syracuse University, and named Dean of the School of Education.
If you have seen videos of children using FC, it should be obvious that the facilitator is doing the communicating (subconsciously) and not the child. It would have been simple to do studies to show that FC didn’t work, but the proponents didn’t do them, because they did not see the need, as they knew it worked. Then FC communications falsely accusing parents of child and sexual abuse began…
The Wikipedia site on FC gives a good summary. An excellent documentary on the controversy, albeit dated in some of its attitudes, can be found at https://archive.org/details/PrisonersofSilence.)
Getting back to leucovorin and folate, I’ve been in the autism field for almost 50 years, and seen this all before. Here are my thoughts and predictions.
I first note that these were preliminary studies, not that rigorous, done with small numbers of children, and weakly positive results (and not all studies were positive). This is fine; they were meant to see if leucovorin was worth looking into further (it is), not to determine if it was a definitive treatment. The authors of the studies did not claim to have made breakthroughs; it is President Trump and Robert Kennedy who are doing this.
If you want to try leucovorin for your child, and can find it, it’s probably safe, so it is reasonable to go ahead, cautiously, no megadoses, but there are no guarantees of safety. Stop if you see adverse effects. If you can’t find it, you can try folic acid, with the same warnings. (As an aside, one consequence of the push for leucovorin could be a nationwide shortage. Leucovorin is a legitimate component of cancer treatment, so this would cause significant harm if cancer patients cannot get it).
There will be good studies done on leucovorin, but not necessarily in this country. This is because the National Institutes of Health may be awarding grants to researchers they expect will be able to prove that it works, which, as I have pointed out in a previous blog, is not how true science is done. The correct approach is to see if the medicine works, but grants with that focus may not be approved. I predict that leucovorin will be popular for a bit, then fall out of favor, but not because of the studies, which will take some time to complete. Instead, it will wane in popularity simply because parents will realize it is not helping. This is what led to the demise of all the other breakthroughs I listed earlier.
This prediction may be wrong, and I hope that it is, but my experience leads me to expect that it is not.
