Short Wave - Tylenol and Autism: What’s True and What Isn’t

Episode Date: September 24, 2025

On Monday, the Trump administration linked the use of Tylenol with rising autism rates, but science doesn’t support that claim. Guest host Sydney Lupkin talks to autism researcher Helen Tager-Flusberg about how autism is studied, the findings from decades of research, and what people–especially those who are pregnant–should do when they experience pain or fever. Plus, we dig into guidance behind using leucovorin to treat autism.Interested in more science behind the headlines? Email us your question at [e-mail] to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hi, shortwavers. Sydney Leapkin in the host chair today. Thank you very much. You probably heard the news this week. Effective immediately, the FDA will be notifying physicians at the use of acid. Well, let's see how we say that. Acetaminophen.

Acetaminophen. Is that okay? which is basically commonly known as Tylenol during pregnancy can be associated with a very increased risk of autism. The president flanked by health secretary Robert F. Kennedy Jr. and head of the Centers for Medicare and Medicaid, Dr. Mehmet Oz, said the common painkiller was to blame for rising autism rates. They said they would update the drug's label. And they also said they would work to update the approval for a vitamin B drug, lucavoren, as a treatment for autism. That's one of the things that I'm very, very happy about.

But the lack of scientific evidence for this new guidance has experts worried. This has been the most devastating week of my career. I had no idea how extremist the perspective would be. Helen Tager Flussberg is a professor emerita, at Boston University in the Department of Psychological and Brain Sciences. And she's the founder of the Coalition of Autism Scientists. Autism is a developmental disability caused by differences in the brain. It impacts the development of a child's cognitive, language, communication, and social abilities.

And it often impacts their sensory processing, their sensory sensitivities. But it's a spectrum. The symptoms can vary. And when it comes to the cause, there are some things scientists know and some things they don't. For instance, we know that exposure to air pollutants and pesticides are linked to higher rates of autism in the population. But for any individual person with autism, it's impossible to say exactly what caused their autism. Today on the show, we'll unpack what this latest announcement means for pregnant people and families with autism. You're listening to Shortwave, the science podcast from NPR.

So, Helen, if we look at the official data coming from the Centers for Disease Control and Prevention about autism, we can see that 25 years ago, the prevalence was one in 150 children. But the latest count is that it's one in 31 children. So what's going on there? What context do we need to understand that? First of all, the awareness of autism has radically changed. 25 years ago, when people asked me what I did, many of them had never heard of autism. Now we take more subtle impairments in social communication or behavior differences.

And even up until 10 years ago, If you had ADHD, you would not be allowed, according to the diagnostic manual, to have a second diagnosis of autism. And in this case, that's really surprising and of course going to make a huge difference because we know that in children, up to half of them, may not only have autism, but also meet diagnostic criteria for ADHD. But I think most important, what we know has changed radically is the availability of services, diagnostic services and intervention services. So let's dive into sort of the research on acetaminopin and autism. Can you give us a sense of the landscape of the research that's out there linking the two or not linking the two? Okay, so we have well over 40 studies, I think, at this point, that are what we call observational.

And we can also then try and link it to whatever data we have available on whether mothers took Tylenol, and how much Tylenol, when, if those data are available. And we can ask the question. So if we have, I'll be simplistic here, we have 100 children diagnosed with autism. And 60 of those mothers reported having taken Tylenol during pregnancy and 40 of them didn't. And then when we look at the patents, we see that more of the children diagnosed with autism, their moms took Tylenol in pregnancy. It's not a huge difference, but it is there. And that's why we say there's a small association.

But we cannot, from these kinds of observational data, make any claims about causality. But then we could take it a step further and ask the question, are mothers of autistic children more likely to be sick, to have those health conditions? Are they more likely to have pain? These might both be related to genetic predispositions, or especially in and of itself, the more prone to poor health. That I think we know maternal health is an important risk factor, not just infections, but also other health conditions that they might have. So we see that these moms who are taking Tylenol may well be different in lots of different ways. So you can't take a simple one-to-one relationship and make any kind of causal connection.

So one follow-up question that I have is, you know, because acetamethin is usually over the counter, Does that make it a challenge to get good data? Because there's not always a medical record for a cash purchase at CBS? I think you hit on an extremely important point. Even the very best study can only rely on what mothers report. They all rely on sort of retrospective report, maybe at the end of the pregnancy, mothers are asked, did you take Tylenol during your pregnancy? And the further away they are from the time when they took the pregnancy, the less likely they are to remember. The data we have

on the actual use of acetaminophen is what I'd call noisy data. Okay. It's not the highest quality. Wow. So the other item that came up during this week's news conference, was lukevourin or philinic acid as a possible autism treatment. But it isn't currently FDA approved for that. It's usually used to counteract the toxic effects of chemotherapy. And GSK, the maker of the original brand name products, says it will work on submitting a supplemental new drug application to get this added to the label. Is there any evidence that this can help people with autism?

How hopeful should people be here? Okay. So I don't think anyone would think that it's going to be helpful for every individual with autism. That said, there have been a couple of small-scale studies. And these small-scale studies have had some promising preliminary findings. At this point, I can't tell you exactly which symptoms we could expect to see change if you put a child on lukevoren. I think the idea of giving a drug for conditions that it wasn't originally thought. I mean, that happens all the time in medicine.

But now the plan is for the FDA to jump over 27 intermediate steps, which they put in place for any other drug recommendation. So just to recap, you don't think that Lucavoren should be taken to treat us. Not yet. I think what we do want are the kinds of clinical trials that the FDA typically requires before they provide approval for any medication. Now, you actually don't need a prescription. It's a philinic acid. It's a kind of variant of a B vitamin. And you can buy it. And most especially, you can buy it through all the wonderful places and companies that sells supplements through the wellness influences. And these are, you know, a significant part of the whole Maha movement. And that's why none of us cynics in the field were surprised to see that of anything, everything in terms of

promising intervention. Picking out Luke Gavorn was an easy target. I've been in this field for decades now, Sydney. We have seen this story play out so many times. You know, there's a small-scale study, promising findings for some new drug treatment for autism. Everybody plumbers to hubbit, and then they actually run the randomized controlled trials, and there's no there there. Are there harms of taking it? So yes, since there's no guidelines at all on dosage for Lucuboran, if I was a mom and buying this tomorrow, I'd have no idea how much to give. I'd be relying on guidance from some other mom to tell me, because physicians, right now are not recommending a lucrevorin as a treatment for autism. So going back to autism and

Tylenol, during the press conference, President Trump also said there were no downsides to avoiding or not taking Tylenol. Is that the case? No, there are downsides to not taking Tylenol. If you're a pregnant woman and you are running a fever and you have a serious infection, the downside of not taking Tylenol is that you are prolonging the time that you are running a fever and infection during pregnancy and stress during pregnancy, we do know increase the risk for autism well above the level of risk that's posed by the Tylenol. I'd also say the downside is women will turn to an alternative way to treat. their pain and fever, and those alternatives are surely less safe than Tylenol.

At the heart of a lot of this administration's actions, including around certain vaccines, is also this idea that autism is inherently bad. As an autism researcher, what do you think about that characterization? So certainly back in April, Secretary Kennedy gave his first press conference in the language that he used to describe autism was simply appalling. Yes, he's talking in some ways about people with profound autism. I study profound autism and I'm under no illusions. It is very complicated. It can be very difficult. It's a huge challenge, especially for the individual who's profoundly autistic, but the impact on the family can also be huge. But at no time did he speak with any humanity or recognize the love that the family members have for their profoundly autistic person?

And then we had a repeat performance yesterday, not only by Secretary Kennedy, but this time by President Trump, they simply don't see these people with disabilities as having any. humanity as being loved by their family. But importantly, profound autism represents a quarter of the population. And the rest of the population are functioning at very different levels. And he was not speaking about them at all, but they too have autism. And so it's as if he's ignoring that there's enormous variability in the expression of this disorder. So, yes, it's very painful to see autism so misrepresented and represented in such a callous way. Helen, thank you so much for coming on the show. Oh, it's my pleasure. This episode was produced by Burley McCoy, edited by Brent Bachman, and fact-checked by Tyler Jones. The audio engineer was Patrick Murray. Beth Donovan is our senior

director and Colin Campbell is our senior vice president of podcasting strategy. I'm Sidney Lepkin. Thank you for listening to Shortwave from NPR.