Flexeril and Sleep paralysis - a phase IV clinical study of FDA data

Summary:

Sleep paralysis is reported as a side effect among people who take Flexeril (cyclobenzaprine hydrochloride), especially for people who are female, 20-29 old, have been taking the drug for 1 - 6 months also take Xyrem, and have Narcolepsy.

The phase IV clinical study analyzes which people have Sleep paralysis when taking Flexeril. It is created by eHealthMe based on reports of 34,789 people who have side effects when taking Flexeril from the FDA, and is updated regularly.

What is Flexeril?

Flexeril has active ingredients of cyclobenzaprine hydrochloride. It is often used in muscle spasms. eHealthMe is studying from 38,308 Flexeril users. Check the latest studies of Flexeril.

What is Sleep paralysis?

Sleep paralysis (waking up and unable to move or speak) is found to be associated with 168 drugs and 278 conditions by eHealthMe. Check the latest studies of Sleep paralysis.

On Jul, 08, 2026

34,789 people reported to have side effects when taking Flexeril.
Among them, 12 people (0.03%) have Sleep paralysis.

Among these 12 people:

How long have people been on Flexeril when they have Sleep paralysis? *

What is the gender of people who have Sleep paralysis when taking Flexeril? *

female: 63.64 %
male: 36.36 %

What is the age of people who have Sleep paralysis when taking Flexeril? *

What are other drugs people take besides Flexeril? *

What are other side effects people have besides Sleep paralysis? *

Depression: 7 people, 58.33%
Weight Fluctuation: 4 people, 33.33%
Pulmonary Embolism (blockage of the main artery of the lung): 4 people, 33.33%
Joint Pain: 4 people, 33.33%
Headache (pain in head): 4 people, 33.33%
Fatigue (feeling of tiredness): 4 people, 33.33%
Obsessive-Compulsive Disorder (an anxiety disorder characterized by intrusive thoughts that produce uneasiness, apprehension, fear, or worry;): 4 people, 33.33%
Drowsiness: 4 people, 33.33%
Vulvovaginal Candidiasis (vulvovaginal infection by fungi): 4 people, 33.33%
Sarcoidosis (an inflammatory disease that affects multiple organs in the body, but mostly the lungs and lymph glands): 4 people, 33.33%

What are the existing conditions these people have? *

Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 7 people, 58.33%
Cataplexy (loss of muscle tone accompanied by full conscious awareness): 5 people, 41.67%
Birth Control: 4 people, 33.33%
Hypothyroidism (abnormally low activity of the thyroid gland, resulting in retardation of growth and mental development): 2 people, 16.67%
Sleep Disorder: 1 person, 8.33%

* Approximation only. Some reports may have incomplete information.

Do you take Flexeril and have Sleep paralysis?

- Check whether Sleep paralysis 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 Flexeril:

Flexeril (38,308 reports)

Sleep paralysis treatments and more:

Sleep paralysis (1,771 reports)

Browse all side effects of Flexeril:

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 Sleep paralysis:

Sleep paralysis (168 drugs)

Browse all the conditions that are associated with Sleep paralysis:

Sleep paralysis (278 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on cyclobenzaprine hydrochloride (the active ingredients of Flexeril) and Flexeril (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.