B12 and Drug ineffective - a phase IV clinical study of FDA data

Summary:

Drug ineffective is reported as a side effect among people who take B12 (cobalamin), especially for people who are female, 60+ old, have been taking the drug for < 1 month also take Vitamin D3, and have Rheumatoid arthritis.

The phase IV clinical study analyzes which people have Drug ineffective when taking B12. It is created by eHealthMe based on reports of 119,647 people who have side effects when taking B12 from the FDA, and is updated regularly.

What is B12?

B12 has active ingredients of cobalamin. It is often used in vitamin b12 deficiency. eHealthMe is studying from 121,894 B12 users. Check the latest studies of B12.

What is Drug ineffective?

Drug ineffective is found to be associated with 4,079 drugs and 5,186 conditions by eHealthMe. Check the latest studies of Drug ineffective.

On May, 09, 2026

119,647 people reported to have side effects when taking B12.
Among them, 7,738 people (6.47%) have Drug ineffective.

Among these 7,738 people:

* Approximation only. Some reports may have incomplete information.

Do you take B12 and have Drug ineffective?

- Check whether Drug ineffective 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 B12:

B12 (121,894 reports)

Drug ineffective treatments and more:

Drug ineffective (1,349,510 reports)

How severe was Drug ineffective and when was it recovered:

Drug ineffective in B12

Expand to all the drugs that have ingredients of cobalamin:

Drug ineffective and drugs with ingredients of cobalamin (7,738 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 B12:

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 Drug ineffective:

Drug ineffective (4,079 drugs)

Browse all the conditions that are associated with Drug ineffective:

Drug ineffective (5,186 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on cobalamin (the active ingredients of B12) and B12 (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.