Loperamide is an antidiarrheal active ingredient available in over-the-counter (OTC) medicines that treat the symptoms of diarrhea, including traveler’s diarrhea. Loperamide can be the only active ingredient in an anti-diarrheal medicine or it can be found in medicines that also treat symptoms such as gas.
Common Products
- Store Brands (ex. Walmart’s “Equate” store brand or CVS Health store brand)
Dosing Information
Different types of products containing this active ingredient 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:
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.
Frequently Asked Questions:
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.
- 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…”
Safety Guide
Safety Guide
Loperamide is approved by the U.S. Food and Drug Administration (FDA) and is safe and effective when used according to the Drug Facts label. Do not exceed the maximum daily dose (8 mg per day for adults).
Ask a healthcare provider before use if:
- You are taking an antibiotic, antifungal, histamine 2 receptor antagonist, HIV medication or gemfibrozil (a cholesterol lowering drug).
- You have a fever.
- You have mucus in your stool.
- You have a history of liver disease.
- You are pregnant or breastfeeding.
- You are taking other prescription and OTC medicines, vitamins, and other dietary supplements.
- Talk to a healthcare provider before giving an OTC containing loperamide to a child under the age of 6.
Do not use if:
- You have ever had a rash or other allergic reaction to loperamide.
- You have bloody or black stool.
- Talk to a healthcare professional prior to use in children under the age of 6.
Stop use and ask a doctor if:
- Your symptoms get worse.
- Your diarrhea lasts for more than two days.
- Seek immediate medical attention if you experience any of the following: fainting; rapid heartbeat or irregular heart rhythm.
- You get abdominal swelling or bulging.
- 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 loperamide?
- Taking higher than recommended doses of loperamide (maximum OTC dose is 8 mg per day for adults), including through abuse or misuse of the product, can cause serious heart problems that can lead to death.
- The risk of serious heart problems may also be increased when high doses of loperamide are taken with medicines that interact with loperamide (see the FDA list of drugs that can potentially interact with loperamide here).
- When using medicines containing loperamide, tiredness, drowsiness, or dizziness may occur.
- You should use care when driving or operating machinery.