Dayquil and Memory loss - a phase IV clinical study of FDA data

Summary:

Memory loss is reported as a side effect among people who take Dayquil (acetaminophen; dextromethorphan; pseudoephedrine), especially for people who are female, 30-39 old, have been taking the drug for < 1 month also take Contac 12 Hour, and have Nasopharyngitis.

The phase IV clinical study analyzes which people have Memory loss when taking Dayquil. It is created by eHealthMe based on reports of 1,538 people who have side effects when taking Dayquil from the FDA, and is updated regularly.

What is Dayquil?

Dayquil has active ingredients of acetaminophen; dextromethorphan; pseudoephedrine. It is often used in cold symptoms. eHealthMe is studying from 1,815 Dayquil users. Check the latest studies of Dayquil.

What is Memory loss?

Memory loss is found to be associated with 2,727 drugs and 4,377 conditions by eHealthMe. Check the latest studies of Memory loss.

eHealthMe: drug outcomes in the real world

eHealthMe runs one of the largest post-marketing drug safety studies in the world. We study millions of patients and 5,000 more each day. Our data-driven phase IV clinical trials have been referenced on 800+ peer-reviewed medical publications including The Lancet, Mayo Clinic Proceedings, and Nature. Tools to study our phase IV findings are available to the public, anonymous and free >>>.

On Jul, 29, 2026

1,538 people reported to have side effects when taking Dayquil.
Among them, 36 people (2.34%) have Memory loss.

Among these 36 people:

How long have people been on Dayquil when they have Memory loss? *

What is the gender of people who have Memory loss when taking Dayquil? *

female: 54.29 %
male: 45.71 %

What is the age of people who have Memory loss when taking Dayquil? *

What are other drugs people take besides Dayquil? *

What are other side effects people have besides Memory loss? *

High Blood Pressure: 9 people, 25.00%
Stress And Anxiety: 9 people, 25.00%
Anhedonia (inability to experience pleasure from activities usually found enjoyable): 7 people, 19.44%
Fatigue (feeling of tiredness): 7 people, 19.44%
Heart Rate Increased: 6 people, 16.67%
Insomnia (sleeplessness): 6 people, 16.67%
Headache (pain in head): 6 people, 16.67%
Dyspnea (difficult or laboured breathing): 6 people, 16.67%
Stroke (sudden death of a portion of the brain cells due to a lack of oxygen): 6 people, 16.67%
Nausea (feeling of having an urge to vomit): 5 people, 13.89%

What are the existing conditions these people have? *

Nasopharyngitis (inflammation of the nasopharynx): 11 people, 30.56%
Cough: 4 people, 11.11%
Depression: 4 people, 11.11%
Multiple Sclerosis (a nervous system disease that affects your brain and spinal cord. it damages the myelin sheath): 4 people, 11.11%
Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 4 people, 11.11%
Nasal Congestion (blockage of the nasal passages usually due to membranes lining the nose becoming swollen from inflamed blood vessels): 4 people, 11.11%
Hiv Infection: 4 people, 11.11%
Cataplexy (loss of muscle tone accompanied by full conscious awareness): 4 people, 11.11%
Oropharyngeal Pain: 3 people, 8.33%
Gait Disturbance: 3 people, 8.33%

* Approximation only. Some reports may have incomplete information.

Do you take Dayquil and have Memory loss?

- Check whether Memory loss is associated with a drug or a condition
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Related studies:

Effectiveness of, long term effects of, and alternative drugs to Dayquil:

Dayquil (1,815 reports)

Memory loss treatments and more:

Memory loss (244,444 reports)

How severe was Memory loss and when was it recovered:

Memory loss in Dayquil

Expand to all the drugs that have ingredients of acetaminophen; dextromethorphan; pseudoephedrine:

Memory loss and drugs with ingredients of acetaminophen; dextromethorphan; pseudoephedrine (21 reports)

Sub-studies by gender and age:

Female: 0-1 2-9 10-19 20-29 30-39 40-49 50-59 60+

Male: 0-1 2-9 10-19 20-29 30-39 40-49 50-59 60+

Browse all side effects of Dayquil:

a b c d e f g h i j k l m n o p q r s t u v w x y z

Browse all the drugs that are associated with Memory loss:

Memory loss (2,727 drugs)

Browse all the conditions that are associated with Memory loss:

Memory loss (4,377 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on acetaminophen; dextromethorphan; pseudoephedrine (the active ingredients of Dayquil) and Dayquil (the brand name). Other drugs that have the same active ingredients (e.g. generic drugs) are not considered. Dosage of drugs is not considered in the study.

How to use the study?

DO NOT STOP MEDICATIONS without first consulting your doctor. If there are any serious or long term adverse effects discovered in the study, discuss the study with your doctor to ensure that proper medication management will be in place if applicable.

Who is eHealthMe?

With medical big data and proven AI/ML algorithms, eHealthMe provides a platform for everyone to run phase IV clinical trials. We study millions of patients and 5,000 more each day. Results of our real-world drug study have been referenced on 800+ peer-reviewed medical publications, including The Lancet, Mayo Clinic Proceedings, and Nature. Our analysis results are available to researchers, health care professionals, patients (testimonials), and software developers (open API).

WARNING, DISCLAIMER, USE FOR PUBLICATION

WARNING: Please DO NOT STOP MEDICATIONS without first consulting a physician since doing so could be hazardous to your health.

DISCLAIMER: All material available on eHealthMe.com is for informational purposes only, and is not a substitute for medical advice, diagnosis, or treatment provided by a qualified healthcare provider. All information is observation-only. Our phase IV clinical studies alone cannot establish cause-effect relationship. Different individuals may respond to medication in different ways. Every effort has been made to ensure that all information is accurate, up-to-date, and complete, but no guarantee is made to that effect. The use of the eHealthMe site and its content is at your own risk.

If you use this eHealthMe study on publication, please acknowledge it with a citation: study title, URL, accessed date.