Chantix and Abnormal behavior - a phase IV clinical study of FDA data

Summary:

Abnormal behavior is reported as a side effect among people who take Chantix (varenicline tartrate), especially for people who are female, 40-49 old, have been taking the drug for 1 - 6 months also take Klonopin, and have Depression.

The phase IV clinical study analyzes which people have Abnormal behavior when taking Chantix. It is created by eHealthMe based on reports of 87,716 people who have side effects when taking Chantix from the FDA, and is updated regularly.

What is Chantix?

Chantix has active ingredients of varenicline tartrate. It is often used in quit smoking. eHealthMe is studying from 89,889 Chantix users. Check the latest studies of Chantix.

What is Abnormal behavior?

Abnormal behavior is found to be associated with 1,384 drugs and 1,938 conditions by eHealthMe. Check the latest studies of Abnormal behavior.

On Jan, 22, 2026

87,716 people reported to have side effects when taking Chantix.
Among them, 2,504 people (2.85%) have Abnormal behavior.

Among these 2,504 people:

* Approximation only. Some reports may have incomplete information.

Do you take Chantix and have Abnormal behavior?

- Check whether Abnormal behavior 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 Chantix:

Chantix (89,889 reports)

Abnormal behavior treatments and more:

Abnormal behavior (51,307 reports)

How severe was Abnormal behavior and when was it recovered:

Abnormal behavior in Chantix

Expand to all the drugs that have ingredients of varenicline tartrate:

Abnormal behavior and drugs with ingredients of varenicline tartrate (2,572 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 Chantix:

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 Abnormal behavior:

Abnormal behavior (1,384 drugs)

Browse all the conditions that are associated with Abnormal behavior:

Abnormal behavior (1,938 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on varenicline tartrate (the active ingredients of Chantix) and Chantix (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.