Tysabri and Weight loss - a phase IV clinical study of FDA data

Summary:

Weight loss is reported as a side effect among people who take Tysabri (natalizumab), especially for people who are female, 50-59 old, have been taking the drug for 1 - 2 years also take Avonex, and have Depression.

The phase IV clinical study analyzes which people have Weight loss when taking Tysabri. It is created by eHealthMe based on reports of 220,870 people who have side effects when taking Tysabri from the FDA, and is updated regularly.

What is Tysabri?

Tysabri has active ingredients of natalizumab. It is often used in multiple sclerosis. eHealthMe is studying from 221,369 Tysabri users. Check the latest studies of Tysabri.

What is Weight loss?

Weight loss is found to be associated with 1,449 drugs and 2,293 conditions by eHealthMe. Check the latest studies of Weight loss.

On May, 01, 2026

220,870 people reported to have side effects when taking Tysabri.
Among them, 310 people (0.14%) have Weight loss.

Among these 310 people:

* Approximation only. Some reports may have incomplete information.

Do you take Tysabri and have Weight loss?

- Check whether Weight loss 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 Tysabri:

Tysabri (221,369 reports)

Weight loss treatments and more:

Weight loss (62,430 reports)

How severe was Weight loss and when was it recovered:

Weight loss in Tysabri

Expand to all the drugs that have ingredients of natalizumab:

Weight loss and drugs with ingredients of natalizumab (310 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 Tysabri:

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 Weight loss:

Weight loss (1,449 drugs)

Browse all the conditions that are associated with Weight loss:

Weight loss (2,293 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on natalizumab (the active ingredients of Tysabri) and Tysabri (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.