Aspirin is an internal analgesic available in over-the-counter (OTC) medicines that temporarily relieve minor aches and pains and reduce fevers. Aspirin is also available in prescription medicines in combination with other ingredients. It is part of a group of pain relievers and fever reducers called non-steroidal anti-inflammatory drugs (NSAIDs). Aspirin can be found in single-ingredient oral pain relievers and fever reducers or in medicines that contain more than one active ingredient to treat migraines. It is also available in medicines that treat symptoms such as heartburn and upset stomach, occasional sleeplessness, migraines, or the multiple symptoms of the common cold.

In March 2019, the American Heart Association (AHA) and the American College of Cardiology (ACC) updated their guidelines for prevention of cardiovascular disease. There is no change to the recommendations for aspirin in preventing a second heart attack or stroke.  If you have not experienced a previous cardiac event, the new guidelines provide more precise criteria to help healthcare providers and patients to better determine, together, if and when aspirin therapy is appropriate. Consumers taking OTC aspirin should always read and follow directions on the Drug Facts label, and the ACC strongly advises people to always speak with their physician before stopping any aspirin regimen.

Symptoms Treated

Symptoms Treated

More specifically: 

Dosing Information

The U.S. Food and Drug Administration (FDA) recommends adults take no more than 4,000 milligrams (mg) of aspirin in a 24-hour period. Different types of products containing aspirin have different strengths. That’s why it is always important to read and follow the Drug Facts label. Most medicines warn against use of an active ingredient for longer than 7-10 days. Stop use and ask a doctor if symptoms persist.

A Note to Families:

While you might have seen media reports or social media posts on observational studies examining potential associations between acetaminophen use during pregnancy and neurodevelopmental outcomes (such as autism), it’s important to note that these studies do not demonstrate a causal relationship. In other words, there is currently no scientific evidence establishing that taking acetaminophen during pregnancy causes neurodevelopmental conditions.
Quick Facts:

1. Scientific and medical authorities around the world recognize acetaminophen as the only analgesic considered safe for use throughout an entire pregnancy when used according to the Drug Facts label.

2. There are no studies showing that acetaminophen use in children or during pregnancy causes autism.

3. Autism has many known risk factors, including genetics, but there is no clear, single cause.

4. Major health authorities like the FDA, CDC, and healthcare organizations such as the American College of Obstetricians and Gynecologists (ACOG) do not have warnings against acetaminophen use during pregnancy based on any known risk of autism and all recommend acetaminophen as the safest analgesic to use during pregnancy for short-term pain relief.
For more information from trusted sources, take a look at ACOG's FAQ and AAP's Update.

Frequently Asked Questions:

Why is acetaminophen used during pregnancy?
Scientific and medical authorities around the world recognize acetaminophen as the only pain reliever and fever reducer considered safe for use throughout an entire pregnancy when used according to the Drug Facts label, which specifically reminds pregnant women to always consult their healthcare provider before use. In fact, the American College of Obstetricians and Gynecologists (ACOG) states that: "Acetaminophen remains a safe, trusted option for pain relief during pregnancy.”
What is autism and does current science indicate what causes it?
Autism is a complex condition with many contributing factors, including genetic, environmental, and prenatal. Most scientists agree that the causes of autism are not simple, nor can they be traced back to one single factor like medication.

In fact, the Autism Science Foundation (ASF), a non-profit organization funding scientific autism research, specifically states that: it is disingenuous and misleading to boil autism's causes down to one simple thing," as there are hundreds of genes linked to autism in addition to other complex environmental factors.

Additionally, the most recent and rigorous research on this topic does not show a causal link to autism. The 2024 study published in the Journal of the American Medical Association (JAMA) analyzed nearly 2.5 million children using the gold-standard sibling comparison method, which controls for shared genetics and family environment, and found no association between acetaminophen use during pregnancy or infancy and neurodevelopmental issues such as autism. 
Why is it important to address fever during pregnancy?
High or long-lasting fevers can harm both the mother and baby and should be taken very seriously. Risks associated with leaving a fever untreated include birth defects, preterm labor, miscarriage, dehydration, or problems with the placenta, which significantly outweigh the risk of treatment.
What do regulatory authorities and major health organizations say?
The CDC and FDA agree acetaminophen is the safest analgesic to use during pregnancy for short-term pain relief, and recommend women to be cautious about overuse, which is why it is always recommended to follow the Drug Facts label and speak to your healthcare provider.  

- CDC Yellow Book (Current as of April 23, 2025): “Acetaminophen remains the non-opioid analgesic of choice during pregnancy.”

- FDA’s Acetaminophen Page (Current as of August 14, 2025): “To date, FDA has not found clear evidence that appropriate use of acetaminophen during pregnancy causes adverse pregnancy, birth, neurobehavioral, or developmental outcomes.”  

Additionally, the Society for Maternal-Fetal Health, a professional organization for obstetricians with subspecialty training in maternal-fetal medicine, stated on September 25, 2025 that it: "...continues to advise physicians and patients that acetaminophen is an appropriate medication to treat pain and fever during pregnancy…the weight of scientific evidence that acetaminophen use during pregnancy causes an increased risk for autism or ADHD is simply inconclusive…”
Is autism really on the rise?
When it comes to reports or claims that autism rates are higher than they were decades ago, the medical community’s ability to now better recognize and diagnose autism must be taken into consideration. Advances in medical knowledge, broader diagnostic criteria, and increased awareness among healthcare providers, educators, and parents mean that more cases are being identified today than in decades past. In other words, autism may not actually be “more common” than it once was; rather, we are better at detecting and recording it.
Is there a cure for autism?
No. There is no cure for autism. Autism is a complex neurodevelopmental condition influenced by many genetic and environmental factors. Treatments and supports focus on improving quality of life, communication, and daily functioning, not on “curing” autism.
What is leucovorin and why are there claims that it can “cure” autism?
Leucovorin (loo-ko-vor-in) is the prescription (Rx) form of folinic acid. It is officially approved by FDA for use in cancer therapy and as an antidote to certain medications. Some small studies have looked at leucovorinin individuals with cerebral folate deficiency (CFD). That’s why some families highlight it as promising. But it’s important to be clear: Leucovorin is not FDA-approved for autism or CFD. Its use for CFD is considered “off-label,” based on limited clinical evidence and physician judgement. On September 24, the FDA published a notice they intended to request that the drug sponsor submit an application to add information on CFD to the prescription drug label. Current research on its effectiveness in treating CFD is limited and preliminary. Calling it a “cure” for autism is misleading and not supported by robust, peer-reviewed evidence.   

Safety Guide

Safety Guide

The U.S. Food and Drug Administration (FDA) is warning that use of nonsteroidal anti-inflammatory drugs (NSAIDs) around 20 weeks or later in pregnancy may cause rare but serious kidney problems in an unborn baby.

Aspirin is approved by FDA and is safe and effective when used according to the Drug Facts label.

Ask a healthcare provider before use if:

  • You drink more than three or more alcoholic drinks a day.
  • You are currently using a medicine containing an NSAID (e.g., magnesium salicylate, naproxen sodium, ibuprofen, ketoprofen).
  • You have stomach problems that last or come back, such as heartburn, upset stomach, or stomach pain; ulcers; or bleeding problems.
  • You have asthma.
  • You are taking a prescription blood thinner (anticoagulant) or a prescription medicine for gout, diabetes, or arthritis.
  • You are pregnant or breastfeeding. Women in the last three months of pregnancy are specifically told not to use aspirin or any other NSAID (e.g., naproxen sodium, magnesium salicylate, ibuprofen, or ketoprofen) without a healthcare provider’s permission.
  • You are considering starting an aspirin regimen. You should not take aspirin for any other reason than what it says on the label unless recommended by a healthcare provider.
  • Talk to your healthcare provider before giving aspirin to children under the age of 12.

Do not use if:

  • You are allergic to aspirin or any other pain reliever or fever reducer.
  • You are a woman in the last three months of pregnancy unless your healthcare provider specifically tells you to. Problems in the unborn child or complications during delivery may occur.
  • Tamper-evident packaging features such as seals, locks, and films are not clear or seem broken.
  • Do not give aspirin to a child or teenager who has or is recovering from the chicken pox or flu, because a rare but serious illness called Reye's syndrome is reported to be associated with aspirin.

Stop use and ask a doctor if:

  • An allergic reaction occurs. Seek medical help right away.
  • Your fever gets worse or lasts more than three days, or if your pain gets worse and lasts more than 10 days.
  • You have signs of stomach bleeding, such as if you feel faint, vomit blood, have stomach pain or upset that lasts or does not get better, or if you have bloody or black stools.
  • Redness or swelling is present in the painful area or if any new symptoms appear.
  • You hear ringing in your ears or you begin to lose your hearing.
  • You take too much. Immediately contact a healthcare provider or the poison control national helpline at 800.222.1222.

What are the side effects of aspirin?

  • Aspirin may cause a severe allergic reaction. Symptoms can include hives, facial swelling, asthma (wheezing), shock, skin reddening, rash, or blisters.
  • Stomach bleeding may occur.