Methimazole and Hyperthyroid - a phase IV clinical study of FDA data

Summary:

Hyperthyroid is reported as a side effect among people who take Methimazole (methimazole), especially for people who are female, 60+ old, have been taking the drug for 1 - 6 months also take Tapazole, and have Atrial fibrillation/flutter.

The phase IV clinical study analyzes which people have Hyperthyroid when taking Methimazole. It is created by eHealthMe based on reports of 7,420 people who have side effects when taking Methimazole from the FDA, and is updated regularly.

What is Methimazole?

Methimazole has active ingredients of methimazole. It is often used in hyperthyroidism. eHealthMe is studying from 8,016 Methimazole users. Check the latest studies of Methimazole.

What is Hyperthyroid?

Hyperthyroid is found to be associated with 1,117 drugs and 1,420 conditions by eHealthMe. Check the latest studies of Hyperthyroid.

On May, 23, 2026

7,420 people reported to have side effects when taking Methimazole.
Among them, 442 people (5.96%) have Hyperthyroid.

Among these 442 people:

How long have people been on Methimazole when they have Hyperthyroid? *

What is the gender of people who have Hyperthyroid when taking Methimazole? *

female: 62 %
male: 38 %

What is the age of people who have Hyperthyroid when taking Methimazole? *

What are other drugs people take besides Methimazole? *

What are other side effects people have besides Hyperthyroid? *

Fatigue (feeling of tiredness): 68 people, 15.38%
Weight Decreased: 57 people, 12.90%
High Blood Pressure: 52 people, 11.76%
Headache (pain in head): 50 people, 11.31%
Drug Ineffective: 50 people, 11.31%
Rashes (redness): 50 people, 11.31%
Dizziness: 48 people, 10.86%
Dyspnea (difficult or laboured breathing): 47 people, 10.63%
Weakness: 46 people, 10.41%
Basedow's Disease (autoimmune disease where the thyroid is overactive, producing an excessive amount of thyroid hormones): 46 people, 10.41%

What are the existing conditions these people have? *

Atrial Fibrillation/flutter (atrial fibrillation and flutter are abnormal heart rhythms in which the atria, or upper chambers of the heart, are out of sync with the ventricles): 59 people, 13.35%
Multiple Sclerosis (a nervous system disease that affects your brain and spinal cord. it damages the myelin sheath): 28 people, 6.33%
Basedow's Disease (autoimmune disease where the thyroid is overactive, producing an excessive amount of thyroid hormones): 26 people, 5.88%
Ventricular Tachycardia (rapid heartbeat that originates in one of the lower chambers (the ventricles) of the heart): 23 people, 5.20%
High Blood Pressure: 21 people, 4.75%
Multiple Myeloma (cancer of the plasma cells): 18 people, 4.07%
Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 18 people, 4.07%
Neuroendocrine Carcinoma (cancer tumour that arise from cells of the endocrine (hormonal) and nervous systems): 18 people, 4.07%
Pain: 15 people, 3.39%
Primary Pulmonary Hypertension (primary high blood pressure that affects the arteries in the lungs and the right side of your heart): 13 people, 2.94%

* Approximation only. Some reports may have incomplete information.

Do you take Methimazole and have Hyperthyroid?

- Check whether Hyperthyroid 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 Methimazole:

Methimazole (8,016 reports)

Hyperthyroid treatments and more:

Hyperthyroid (26,832 reports)

Browse all side effects of Methimazole:

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 Hyperthyroid:

Hyperthyroid (1,117 drugs)

Browse all the conditions that are associated with Hyperthyroid:

Hyperthyroid (1,420 conditions)

How the study uses the data?

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