After public comments urging pregnant women to avoid Tylenol, researchers observed a noticeable shift in prescribing patterns, according to findings published in The Lancet.
On September 22, President Donald Trump stated that pregnant women should avoid Tylenol and said the Food and Drug Administration would alert physicians about a possible link between use during pregnancy and autism in children. He advised pregnant women not to take the medication.
Current scientific evidence does not confirm such a link. The FDA’s communication to physicians described the issue as an “ongoing area of scientific debate.” A comprehensive review published in January — one of the most detailed analyses to date — found no association between acetaminophen (also known as paracetamol, the active ingredient in Tylenol) and neurodevelopmental disorders, including autism.
A Measurable Decline in Use
To assess the potential impact of the public remarks, researchers at Harvard Medical School and Brown University examined electronic health records from emergency departments. They compared acetaminophen prescriptions written for pregnant patients between September 22 and December 7 with prescriptions from the nearly three months preceding the announcement.
The analysis showed a 10% reduction in orders for acetaminophen among pregnant patients. No comparable decline was observed among women who were not pregnant.
Researchers believe the timing and abrupt nature of the change suggest that the public statement influenced perceptions about the medication’s safety. The available data do not clarify whether the decrease resulted primarily from patient reluctance or physician caution, though investigators suggest patients declining the medication may have played a significant role.
Clinical Guidance Remains Unchanged
Professional medical organizations continue to regard acetaminophen as one of the limited pain and fever medications considered appropriate during pregnancy when used as directed. The American College of Obstetricians and Gynecologists advises that untreated fever during pregnancy may pose risks to both mother and fetus, including certain birth defects.
The manufacturer of Tylenol, Kenvue, states that pregnant individuals should consult a healthcare professional before use, consistent with product labeling. The company also reports that available data do not establish a proven link between acetaminophen and autism.
It remains difficult to assess the broader impact on over-the-counter purchases. Kenvue reports sales at the business segment level rather than by individual product. In its most recent quarterly earnings, the company noted a modest increase in overall self-care sales, a category that includes Tylenol among other products.
A Surge in Prescriptions for Leucovorin
Researchers also examined prescribing trends for leucovorin, a medication discussed at the same press event as a potential treatment for autism symptoms.
Electronic health record data showed a 71% increase in new leucovorin prescriptions for children ages 5 to 17 in the two and a half months following the announcement.
Leucovorin, also called folinic acid, is a synthetic form of vitamin B9 commonly used in cancer treatment to reduce the toxic effects of chemotherapy. A small number of clinical studies — many conducted outside the United States — have explored its potential role in certain children with autism. However, the American Academy of Pediatrics states that more evidence is required before routine use can be recommended.
In September, the FDA indicated it was updating leucovorin’s labeling to include use in patients with cerebral folate deficiency, a rare neurological disorder involving low vitamin B9 levels in the brain. Some researchers have proposed that this condition may overlap with autism in a subset of patients, though it does not apply to all individuals with autism.
Broader Public Health Implications
Leucovorin is generally associated with mild side effects in oncology settings. However, prescribing medications for unproven uses can raise concerns, including unrealistic expectations among families and potential strain on drug supply. Certain formulations of leucovorin are currently in short supply in the United States, though the reasons are not fully clear.
The findings underscore how public health messaging — particularly from federal officials — can rapidly influence medical decisions and prescribing behavior. Researchers note that while awareness of medications and conditions can encourage care-seeking, clear communication grounded in established evidence remains essential.
For patients, especially during pregnancy or when managing chronic conditions, healthcare decisions are best made in consultation with qualified medical professionals who can review current evidence and individual health factors.
