Letrozole and Breast enlargement - a phase IV clinical study of FDA data

Summary:

Breast enlargement is reported as a side effect among people who take Letrozole (letrozole), especially for people who are female, 30-39 old, have been taking the drug for 1 - 6 months also take Follistim, and have Breast pain.

The phase IV clinical study analyzes which people have Breast enlargement when taking Letrozole. It is created by eHealthMe based on reports of 53,470 people who have side effects when taking Letrozole from the FDA, and is updated regularly.

What is Letrozole?

Letrozole has active ingredients of letrozole. It is often used in breast cancer. eHealthMe is studying from 54,125 Letrozole users. Check the latest studies of Letrozole.

What is Breast enlargement?

Breast enlargement is found to be associated with 340 drugs and 540 conditions by eHealthMe. Check the latest studies of Breast enlargement.

eHealthMe: drug outcomes in the real world

eHealthMe runs one of the largest post-marketing drug safety studies in the world. We study millions of patients and 5,000 more each day. Our data-driven phase IV clinical trials have been referenced on 800+ peer-reviewed medical publications including The Lancet, Mayo Clinic Proceedings, and Nature. Tools to study our phase IV findings are available to the public, anonymous and free >>>.

On Aug, 20, 2026

53,470 people reported to have side effects when taking Letrozole.
Among them, 14 people (0.03%) have Breast enlargement.

Could Letrozole cause Breast enlargement?

Among these 14 people:

How long have people been on Letrozole when they have Breast enlargement? *

What is the gender of people who have Breast enlargement when taking Letrozole? *

female: 100 %
male: 0.0 %

What is the age of people who have Breast enlargement when taking Letrozole? *

What are other drugs people take besides Letrozole? *

What are other side effects people have besides Breast enlargement? *

Fatigue (feeling of tiredness): 7 people, 50.00%
Maternal Exposure During Pregnancy (use of substance during pregnancy): 6 people, 42.86%
Gastric Ulcer (stomach ulcer): 4 people, 28.57%
Pain: 4 people, 28.57%
Haemorrhage (bleeding): 4 people, 28.57%
Depression: 4 people, 28.57%
Delirium (wild excitement): 4 people, 28.57%
Hallucination, Visual (seeing things that aren't there): 4 people, 28.57%
Stress And Anxiety: 4 people, 28.57%
Breast Lump (localized swelling that feels different from the surrounding breast tissue): 4 people, 28.57%

What are the existing conditions these people have? *

Infertility: 4 people, 28.57%
Breast Pain: 4 people, 28.57%
Maternal Therapy To Enhance Foetal Lung Maturity: 2 people, 14.29%
Affective Disorder (mental disorder): 2 people, 14.29%
Spinal Column Stenosis (narrowing of spinal column): 1 person, 7.14%
Paraesthesia (sensation of tingling, tickling, prickling, pricking, or burning of a person's skin with no apparent long-term physical effect): 1 person, 7.14%
Osteopenia (a condition where bone mineral density is lower than normal): 1 person, 7.14%
Neuralgia (pain in one or more nerves): 1 person, 7.14%
Joint Pain: 1 person, 7.14%
High Blood Cholesterol: 1 person, 7.14%

* Approximation only. Some reports may have incomplete information.

Do you take Letrozole and have Breast enlargement?

- Check whether Breast enlargement 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 Letrozole:

Letrozole (54,125 reports)

Browse all side effects of Letrozole:

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 Breast enlargement:

Breast enlargement (340 drugs)

Browse all the conditions that are associated with Breast enlargement:

Breast enlargement (540 conditions)

How the study uses the data?

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