Highlights
Age Groups Seen
- Infant 0-2
- Child 3-12
- Adolescent 13-17
- Young Adult 18-25
- Adult 26-64
- Older Adult 65+
Languages
- French
- English
In-Network Plans
View All Accepted Plans (12)Gender
FemaleJohns Hopkins Affiliations:
- Johns Hopkins School of Medicine Faculty
About Jenna S. Mammen
Primary Academic Title
Associate Professor of Medicine
Johns Hopkins Physician
Background
Jennifer Mammen, M.D., Ph.D., Assistant Professor of Medicine, is a member the Division of Endocrinology, Diabetes and Metabolism.
Dr. Mammen practices general endocrinology with a focus on thyroid, adrenal and pituitary disorders. She is actively engaged in research on hormonal function and aging.
Research Interests
Thyroid, adrenal and pituitary function in aging
Research Summary
An appreciation for the complexity of human responses to aging has allowed us to recognize that there are multiple pathophysiology processes behind seemingly similar clinical changes in serum hormone levels among older adults. Using data from the Baltimore Longitudinal Study of Aging, we have recently reported the novel observation that most healthy older adults have relatively stable thyroid function, despite higher average levels among older compared to younger groups. We have demonstrated the presence of diverse aging patterns in the thyroid axis amongst older adults. In particular, while some people clearly have developing hypothyroidism from primary thyroid failure, others have changes in their pituitary that give rise to a similar TSH elevation without lowering thyroid hormone levels. These different patterns imply different treatment approaches are appropriate in individuals. Ongoing research is directed towards being able to distinguish these differences without the long-term follow up data that is available in the BLSA, in order to develop clinically relevant tests and improve care. We have identified practice patterns and risk factors for thyroid hormone over-use and misuse that constitute a significant public health problem in older adults, and particularly women, which drives the need for targeted therapy and personalized medicine to come to endocrinology.
Selected Publications
Mammen JS, McGready J, Ladenson PW, Simonsick EM. Unstable thyroid function in older adults is caused by alternations in both thyroid and pituitary physiology and associated with increased mortality. Thyroid 2017; 27(11)1370 [PMID 28854871]
Mammen JS, McGready J, Oxman R, Chia CW, Ladenson PW, Simonsick EM. Thyroid hormone therapy and risk of thyrotoxicosis in community-resident older adults: Findings from the Baltimore Longitudinal Study of Aging. Thyroid. 2015; 25(9):979 [PMID: 26177259]
Mammen, JS and Cooper D, “Lobectomy vs total thyroidectomy in suspicious or malignant lesions” in Transoral Endocrine and Neck Surgery, edited by Russell JO, Tufano R, and Inabnet WB ed. In press. Springer.
Brahmer JR, Lacchetti C, Schneider BJ, Atkins MB, Brassil KJ, Caterino JM, Chau I, Ernstoff MS, Gardner JM, Ginex P, Hallmeyer S, Holter Chakrabarty J, Leighl NB, Mammen JS, McDermott DF, Naing A, Nastoupil LJ, Phillips T, Porter LD, Puzanov I, Reichner CA, Santomasso BD, Seigel C, Spira A, Suarez-Almazor ME, Wang Y, Weber JS, Wolchok JD, Thompson JA. Managements of Immune-Related Adverse Events in Pathients Treated With Immune Checkpoint Inhibitor Therapy: American Society of Clinical Oncology Clinical Practice Guideline Jclin Oncol 2018 Feb 14 [Epub ahead of print] [PMID: 29442540].
Simonsick EM, Chia CW, Mammen JS, Egan JM, Ferrucci L. Free Thyroxine and Functional Mobility, Fitness, and Fatigue in Euthyroid Older Men and Women in the Baltimore Longitudinal Study of Aging. J Gerontol A Biol Sci Med Sci. 2016; 71(7):961 [PMID: 26791089]
Honors
- Turock Clinical Scholar, Turock Family Foundation, 7/1/16
- Passano Physician Scientist, Passano Foundation, 4/1/13
- Alpha Omega Alpha, 5/30/04
- Medical Scientist Training Program, National Institutes of Health, 7/1/95
- Churchill Scholar, Churchill Foundation, 7/1/91
Memberships
- American Thyroid Association
- Endocrine Society
Additional Training
- M.Phil., University of Cambridge (United Kingdom) (1992)
- PhD, Johns Hopkins Bloomberg School of Public Health (2004)
Locations
- Johns Hopkins Bayview Medical Center
- 4940 Eastern Avenue, Bayview Medical Offices, Level 01 (G), Clinic 4, Baltimore, MD 21224
- Get Directions
- phone: 410-955-9270
- fax: 410-367-2042
- Johns Hopkins Health Care & Surgery Center - Green Spring Station, Lutherville
- 10751 Falls Road, Falls Concourse STE 412, Lutherville, MD 21093
- Get Directions
- phone: 410-955-9270
- fax: 410-367-2042
Expertise
Education
- Fellowship: Johns Hopkins University School of Medicine, Endocrinology, 2010
- Residency: Johns Hopkins University School of Medicine, Medicine, 2006
- Graduate School: Johns Hopkins Bloomberg School of Public Health, PhD, 2004
- Medical Education: Johns Hopkins University School of Medicine, MD, 2004
Board Certifications
- Endocrinology Diabetes and Metabolism: American Board of Internal Medicine, 2010
Insurance
- Aetna
- CareFirst
- Cigna
- First Health
- Geisinger Health Plan
- HealthSmart/Accel
- Johns Hopkins Health Plans
- MultiPlan
- Pennsylvania's Preferred Health Networks (PPHN)
- Point Comfort Underwriters
- Private Healthcare Systems (PHCS)
- Veteran Affairs Community Care Network (Optum-VACCN)
Ratings & Reviews
4.9 out of 5
122 ratings, 53 reviewsThe Patient Rating score is an average of all responses to physician related questions on the national CG-CAHPS Medical Practice patient experience survey through Press Ganey. Responses are measured on a scale of 1 to 5, with 5 being the best score. Comments are also gathered from our CG-CAHPS Medical Practice Survey through Press Ganey and displayed in their entirety. Patients are de-identified for confidentiality and patient privacy.
- 4 out of 5 starsReviewed on 3/9/2026
Good
- 5 out of 5 starsReviewed on 3/9/2026
Dr Mammen is an excellent doctor, very thorough, caring and concerned.
- 5 out of 5 starsReviewed on 2/19/2026
Dr Mammen
- 5 out of 5 starsReviewed on 2/12/2026
Was excelent
- 5 out of 5 starsReviewed on 2/12/2026
She is excellent takes time to explain things and Dr. MAMMEN gives fast response on my chart. She is so smart and kind.
- 5 out of 5 starsReviewed on 2/2/2026
Dr Mammen is a great specialist:kind, knowlegeable
- 5 out of 5 starsReviewed on 2/2/2026
Warm, caring, extremely knowledgeable
- 5 out of 5 starsReviewed on 1/29/2026
Video visit not as thorough
- 5 out of 5 starsReviewed on 1/29/2026
She is very good good
- 5 out of 5 starsReviewed on 1/15/2026
5 stars all day every visit
- 5 out of 5 starsReviewed on 1/12/2026
Professional and explained very clearly
- 5 out of 5 starsReviewed on 1/8/2026
The resident, [staff] was very thorough, considerate, and engaged. [staff] conducted a very detailed medication reconciliation process and asked relevant questions. Dr. Mammen was efficient, respectful, a great listener and provided me with the most evidence-based treatment considerations so that I can be well prepared for our next visit. I could not be more pleased and I know that I am in very competent hands.
- 5 out of 5 starsReviewed on 12/22/2025
Knowledgeable, intelligent, easy to understand
- 5 out of 5 starsReviewed on 12/18/2025
Excellent
- 5 out of 5 starsReviewed on 12/8/2025
The Dr. Mammen was very knowledgeable and reviewed associated tests from other provider and connected the dots for me.
- 5 out of 5 starsReviewed on 12/4/2025
Thoughtful, warm, attentive, knowledgeable
- 5 out of 5 starsReviewed on 12/4/2025
Excellent physician
- 5 out of 5 starsReviewed on 11/24/2025
Dr Mammen is considerate and never rush on medications unless necessary. This is one thing I admire about her that she makes sure to inform the need of medication and would listen to the patient's concerns. She alsoProvides prompt response on any health related query over the patient portal
- 5 out of 5 starsReviewed on 11/20/2025
Microphone on my pc was faulty so provider called me and we continued with phone and pc together-so she is very resourceful.
- 5 out of 5 starsReviewed on 11/20/2025
Dr. Mammem is the finest physician I have, as well, an equally fine person.
- 5 out of 5 starsReviewed on 11/13/2025
Dr. Mammen has provided excellent care. She was reassuring in my treatment and worked with me to create a plan for management. Very knowledgeable and professional.
- 5 out of 5 starsReviewed on 11/5/2025
Dr mammen is the best. She gets my thyroid numbers correct all the time and explains what meds Interfere with thyroid meds. Very knowegeable
- 5 out of 5 starsReviewed on 10/15/2025
Provider was very thorough and gave excellent advice
- 5 out of 5 starsReviewed on 10/15/2025
Very nice
- 3 out of 5 starsReviewed on 10/13/2025
I do not feel that the provider explains thyroid health conditions very well to the patient.
- 5 out of 5 starsReviewed on 10/9/2025
Dr Mammen is the best for my problem. She got me off a medicine which I had taken for years. She has knowledge of the latest research in her field of medicine.
- 5 out of 5 starsReviewed on 9/17/2025
Very professional and trustworthy.
- 5 out of 5 starsReviewed on 9/17/2025
Dr. Mammen knows her field well and communicates clearly about all of her OWN concerns for a patient and their personal concerns and questions as well. She is a real credit to JHH.
- 5 out of 5 starsReviewed on 9/16/2025
Dr Mammen is excellent. It is hard to get an appointment without 3-4 month wait
- 5 out of 5 starsReviewed on 9/16/2025
Dr. Mammen is always punctual for my appointments. She is very thorough and does a great job answering my questions and explaining information.
- 5 out of 5 starsReviewed on 9/15/2025
Provider listened, responded with candor and was clear about next steps.
- 5 out of 5 starsReviewed on 9/3/2025
Dr. Mammen is excellent not only listening to my medical problems, but the stress I am under trying to care for 4, 8 and 11 year old girls at my age, since their mother has been removed from the house. Dr. Mammen shows patience and empathy.
- 5 out of 5 starsReviewed on 8/21/2025
She was very good
- 5 out of 5 starsReviewed on 8/11/2025
Good communication
- 5 out of 5 starsReviewed on 7/16/2025
Dr. Mammen is terrific! She explains reasons for the recommended course of treatment and shares next steps that leave us comfortable that she's monitoring progress and ready to make any needed changes if indicated.
- 5 out of 5 starsReviewed on 7/10/2025
This provider spoke in terms that I could understand.
- 5 out of 5 starsReviewed on 7/7/2025
Everything was fine.
- 5 out of 5 starsReviewed on 7/2/2025
Dr. Mammen was the first doctor to figure out what was wrong with my thyroid in over ten years of my searching for someone who would listen to what I was saying. I was headed towards serious health concerns, but Dr. Mammen got me back on track where I should be.
- 5 out of 5 starsReviewed on 6/30/2025
Friendly, efficient and assuring.
- 5 out of 5 starsReviewed on 6/16/2025
Dr. Mammen is very thorough and efficient.
- 5 out of 5 starsReviewed on 6/16/2025
Kind and knowlegeable
- 5 out of 5 starsReviewed on 6/12/2025
Excellent communication skills by primary physician and Resident. Very clear communication about related past procedures and tests from GBMC going back 15 years as well as JHU and private providers. WOW can they both type notes FAST and converse with me on complicated history simultaneously.
- 5 out of 5 starsReviewed on 6/12/2025
Excellent physician.
- 5 out of 5 starsReviewed on 6/5/2025
Caring, compassionate,
- 5 out of 5 starsReviewed on 5/21/2025
Dr.Mammen and her nurse are wonderful people and excellent in what they do.
- 5 out of 5 starsReviewed on 5/19/2025
Excellent experience
- 5 out of 5 starsReviewed on 5/12/2025
The visit with Dr. Mammen was the best possible appointment and definitely the best medical attention that I have received in a long time. She answered all of my questions and was open to what I had to say. She treated my person and not just my lab results. I wish I had found her sooner!
- 5 out of 5 starsReviewed on 5/8/2025
Dr. Mammen is an excellent provider. She listens and includes me in the decision making process for my healthcare. I also appreciate her timeliness and responsiveness to questions I have and updates about my care.
- 5 out of 5 starsReviewed on 5/7/2025
Dr Mammen had read my scans and blood work prior to meeting with me. Very impressed with that and her expertise. She asked me some questions and went over what my Scans and bloodwork. She had definite answers to how I've been feeling based upon the blood work. Very grateful for Dr. Mammen. She explained everything in layman's terms, And I am on a path to feeling much better. I highly recommend Dr. Mammen
- 5 out of 5 starsReviewed on 5/5/2025
Dr. Mammen is professional and knowledgeable. She listens to her patient and explains things in an easier way.
- 5 out of 5 starsReviewed on 4/24/2025
Knowledgable about Adrenal Insuffuciency! Confident during review with me and clear communicator.
- 5 out of 5 starsReviewed on 4/24/2025
Dr. Mammen is an excellent physician. She is very knowledgeable and explains conditions/treatments well.
- 5 out of 5 starsReviewed on 4/21/2025
Dr. Mammen was very clear in our communication.. She was Very thoughtful about what she said and gave us a lot of confidence that we are in good hands