Nyquil and Weakness - a phase IV clinical study of FDA data

Summary:

Weakness is reported as a side effect among people who take Nyquil (acetaminophen / dextromethorphan / doxylamine / pseudoephedrine), especially for people who are female, 60+ old, have been taking the drug for < 1 month also take Tylenol, and have Stress and anxiety.

The phase IV clinical study analyzes which people have Weakness when taking Nyquil. It is created by eHealthMe based on reports of 2,013 people who have side effects when taking Nyquil from the FDA, and is updated regularly.

What is Nyquil?

Nyquil has active ingredients of acetaminophen / dextromethorphan / doxylamine / pseudoephedrine. It is often used in cold symptoms. eHealthMe is studying from 2,240 Nyquil users. Check the latest studies of Nyquil.

What is Weakness?

Weakness is found to be associated with 3,638 drugs and 6,618 conditions by eHealthMe. Check the latest studies of Weakness.

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 Aug, 06, 2026

2,013 people reported to have side effects when taking Nyquil.
Among them, 62 people (3.08%) have Weakness.

Among these 62 people:

How long have people been on Nyquil when they have Weakness? *

What is the gender of people who have Weakness when taking Nyquil? *

female: 61.67 %
male: 38.33 %

What is the age of people who have Weakness when taking Nyquil? *

What are other drugs people take besides Nyquil? *

What are other side effects people have besides Weakness? *

Fatigue (feeling of tiredness): 27 people, 43.55%
Nausea (feeling of having an urge to vomit): 16 people, 25.81%
Pain In Extremity: 14 people, 22.58%
Nausea And Vomiting: 13 people, 20.97%
Dizziness: 13 people, 20.97%
Malaise (a feeling of general discomfort or uneasiness): 11 people, 17.74%
Diarrhea: 11 people, 17.74%
Feeling Abnormal: 11 people, 17.74%
Gait Disturbance: 8 people, 12.90%
Headache (pain in head): 8 people, 12.90%

What are the existing conditions these people have? *

Stress And Anxiety: 8 people, 12.90%
Multiple Sclerosis (a nervous system disease that affects your brain and spinal cord. it damages the myelin sheath): 7 people, 11.29%
High Blood Cholesterol: 6 people, 9.68%
Multiple Myeloma (cancer of the plasma cells): 6 people, 9.68%
Pain: 6 people, 9.68%
High Blood Pressure: 5 people, 8.06%
Hypersensitivity: 5 people, 8.06%
Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 5 people, 8.06%
Erection Problems: 4 people, 6.45%
Prostate Cancer: 3 people, 4.84%

* Approximation only. Some reports may have incomplete information.

Do you take Nyquil and have Weakness?

- Check whether Weakness is associated with a drug or a condition
- Predict drug outcomes for up to one year with AI
- Get an AI agent to monitor your drugs continuously

Related studies:

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

Nyquil (2,240 reports)

Weakness treatments and more:

Weakness (586,877 reports)

How severe was Weakness and when was it recovered:

Weakness in Nyquil

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

Weakness and drugs with ingredients of acetaminophen / dextromethorphan / doxylamine / pseudoephedrine (65 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 Nyquil:

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 Weakness:

Weakness (3,638 drugs)

Browse all the conditions that are associated with Weakness:

Weakness (6,618 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on acetaminophen / dextromethorphan / doxylamine / pseudoephedrine (the active ingredients of Nyquil) and Nyquil (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.