Benadryl and Gastric bypass - a phase IV clinical study of FDA data

Summary:

Gastric bypass is reported as a side effect among people who take Benadryl (diphenhydramine hydrochloride), especially for people who are male, 60+ old, have been taking the drug for < 1 month also take Cymbalta, and have Rheumatoid arthritis.

The phase IV clinical study analyzes which people have Gastric bypass when taking Benadryl. It is created by eHealthMe based on reports of 100,139 people who have side effects when taking Benadryl from the FDA, and is updated regularly.

What is Benadryl?

Benadryl has active ingredients of diphenhydramine hydrochloride. It is often used in allergies. eHealthMe is studying from 104,954 Benadryl users. Check the latest studies of Benadryl.

What is Gastric bypass?

Gastric bypass is found to be associated with 243 drugs and 333 conditions by eHealthMe. Check the latest studies of Gastric bypass.

On Jul, 14, 2026

100,139 people reported to have side effects when taking Benadryl.
Among them, 18 people (0.02%) have Gastric bypass.

Among these 18 people:

How long have people been on Benadryl when they have Gastric bypass? *

What is the gender of people who have Gastric bypass when taking Benadryl? *

female: 41.18 %
male: 58.82 %

What is the age of people who have Gastric bypass when taking Benadryl? *

What are other drugs people take besides Benadryl? *

What are other side effects people have besides Gastric bypass? *

Pain: 12 people, 66.67%
Fatigue (feeling of tiredness): 12 people, 66.67%
Tremor (trembling or shaking movements in one or more parts of your body): 11 people, 61.11%
Drug Hypersensitivity: 10 people, 55.56%
Constipation: 10 people, 55.56%
Drug Ineffective: 9 people, 50.00%
Synovitis (inflammation of the synovial membrane): 9 people, 50.00%
Adverse Drug Reaction: 8 people, 44.44%
Nausea (feeling of having an urge to vomit): 7 people, 38.89%
Abdominal Pain Upper: 6 people, 33.33%

What are the existing conditions these people have? *

Rheumatoid Arthritis (a chronic progressive disease causing inflammation in the joints): 9 people, 50.00%
Crohn's Disease (a condition that causes inflammation of the gastrointestinal tract): 3 people, 16.67%
Multiple Sclerosis (a nervous system disease that affects your brain and spinal cord. it damages the myelin sheath): 2 people, 11.11%
Herpes Zoster: 2 people, 11.11%
Weight Decreased: 1 person, 5.56%
Ovarian Cancer Stage Iv: 1 person, 5.56%
Nausea (feeling of having an urge to vomit): 1 person, 5.56%
Hypersensitivity: 1 person, 5.56%
High Blood Pressure: 1 person, 5.56%
Gastroesophageal Reflux Disease (a condition in which stomach contents leak backward from the stomach into the oesophagus): 1 person, 5.56%

* Approximation only. Some reports may have incomplete information.

Do you take Benadryl and have Gastric bypass?

- Check whether Gastric bypass 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 Benadryl:

Benadryl (104,954 reports)

Gastric bypass treatments and more:

Gastric bypass (3,008 reports)

Browse all side effects of Benadryl:

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 Gastric bypass:

Gastric bypass (243 drugs)

Browse all the conditions that are associated with Gastric bypass:

Gastric bypass (333 conditions)

How the study uses the data?

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