Department Endocrinology, Diabetes and Metabolism
Primary Location Twinsburg Family Health & Surgery Center
Type of Doctor Adults Only
Languages English
Surgeon No
Twinsburg Family Health & Surgery Center
Primary Location

Twinsburg Family Health & Surgery Center


Additional Locations

Specialties & Treatments

Treatment & Services

  • Blood Tests
  • Bone Density Testing
  • Fine Needle Aspiration
  • General Endocrinology
  • Radioactive Iodine Treatment
  • Thyroid Aspiration
  • Thyroid Ultrasound
  • Thyroid Ultrasound And Biopsy
View all 8 Treatment & Services +

Specialty in Diseases & Conditions

  • Acromegaly
  • Adrenal disorders
  • Adrenal insufficiency
  • Androgen Deficiency (Low Testosterone)
  • Androgen Excess
  • Beta-cell disorders
  • Bone Disorders
  • Calcium Disorders
  • Carcinoid Syndrome
  • Cushing's Syndrome
  • Diabetes
  • Diabetes - Management
  • Diabetes, Gestational
  • Empty sella
  • Endocrine Complications of Pregnancy
  • Endocrine Disorders
  • Fasting hypoglycemia
  • Flushing Syndromes
  • Galactorrhea
  • Goiter
  • Growth hormone deficiency
  • Growth hormone excess
  • Gynecomastia
  • Hair Loss in Women
  • High Cholesterol
  • Hirsutism
  • Hyperaldosteronism
  • Hyperandrogenism
  • Hypercalcemia
  • Hyperparathyroidism
  • Hyperprolactinemia
  • Hyperthyroidism
  • Hypertriglyceridemia
  • Hypocalcemia
  • Hypogonadism
  • Hypoparathyroidism
  • Hypophysitis
  • Hypopituitarism
  • Hypothyroidism
  • Klinefelter Syndrome
  • Male Infertility Testing
  • Metabolic Bone Disease
  • Metabolic Diseases
  • Metabolic Syndrome
  • Osteopenia
  • Osteoporosis
  • Panhypopituitarism
  • Parathyroid Disease Description
  • Pheochromocytoma
  • Pituitary Cysts
  • Pituitary Disorders
  • Pituitary stalk lesions
  • Pituitary Tumors
  • Polycystic Ovary Syndrome
  • Primary Hyperaldosteronism
  • Prolactin Excess States
  • Prolactinoma
  • Pseudohypoparathyroidism
  • Reactive hypoglycemia
  • Secondary Hyperparathyroidism
  • Tertiary hyperparathyroidism
  • Thyroid and pregnancy
  • Thyroid Cancer
  • Thyroid Disease
  • Thyroid Nodule
  • Vitamin D Deficiency
View all 66 Specialties +


Is Cleveland Clinic Part of Your Insurance?

Review a list of accepted insurance plans for our Northeast Ohio locations or learn more about purchasing a contracted managed care plan.

View All Plans

About Guy Mulligan, MD

Dr. Guy Mulligan has been appointed as Associate Staff in Endocrinology, Diabetes and Metabolism as of July 2010.  Dr. Mulligan graduated from medical school at the University of Toledo, Ohio in 2005.  He completed his medical residency at the University of Michigan, Ann Arbor, Michigan, in 2008.  He completed his fellowship training in endocrinology at the Cleveland Clinic, Cleveland, Ohio in 2010.  He participated in clinical research during his endocrinology fellowship in the areas of vitamin D therapy and inferior petrosal sinus sampling in the diagnosis of ACTH-dependent Cushing's syndrome.  He enjoys evaluating and treating a wide variety of problems within the field of endocrinology, diabetes and metabolism.
Education & Professional Highlights

Education & Professional Highlights


Education & Fellowships

Fellowship - Cleveland Clinic
Cleveland, OH USA

Residency - University of Michigan Health System
Internal Medicine
Ann Arbor, MI USA

Medical Education - University of Toledo College of Medicine
Toledo, OH USA

Undergraduate - College of Wooster
Wooster, OH USA


  • Internal Medicine
  • Internal Medicine - Endocrinology, Diabetes and Metabolism

Specialty Interests

Type 2 diabetes mellitus, insulin resistance/pre-diabetes/PCOS, hyperthyroidism, thyroid nodules, primary hyperparathyroidism, hypothyroidism in pregnancy, male hypogonadism, pituitary adenoma, hyperprolactinemia, osteoporosis

Research & Publications

Research & Publications

See publications for Guy Mulligan, MD.

(Disclaimer: This search is powered by PubMed, a service of the U.S. National Library of Medicine. PubMed is a third-party website with no affiliation with Cleveland Clinic.)

Industry Relationships

Industry Relationships

Cleveland Clinic physicians and scientists may collaborate with the pharmaceutical or medical device industries to help develop medical breakthroughs or provide medical expertise or education. Cleveland Clinic strives to make scientific advances that will benefit patient care and support outside relationships that promise public benefit. In order for the discoveries of Cleveland Clinic physicians' and scientists' laboratories and investigations to benefit the public, these discoveries must be commercialized in partnership with industry. As experts in their fields, Cleveland Clinic physicians and scientists are often sought after by industry to consult, provide expertise and education.

To assure professional and commercial integrity in such matters, Cleveland Clinic maintains a program that reviews these collaborations and, when appropriate, puts measures in place to minimize bias that may result from ties to industry. Cleveland Clinic publicly discloses the names of companies when (i) its physicians/scientists receive $5,000 or more per year (or, in rare cases, equity or stock options) for speaking and consulting, (ii) its physicians/scientists serve as a fiduciary, (iii) its physicians/scientists receive or have the right to receive royalties or (iv) its physicians/ scientists hold any equity interest for the physician's/scientist's role as inventor, discoverer, developer, founder or consultant.* In publicly disclosing this information, Cleveland Clinic tries to provide information as accurately as possible about its physicians' and scientists' connections with industry.

As of 11/19/2018, Dr. Mulligan has reported no financial relationship with industry that is applicable to this listing. In general, patients should feel free to contact their doctor about any of the relationships and how the relationships are overseen by Cleveland Clinic. To learn more about Cleveland Clinic's policies on collaborations with industry and innovation management, go to our Integrity in Innovation page.

Public Health Service-Reportable Financial Conflicts of Interest. Cleveland Clinic scientists and physicians engage in basic, translational and clinical research activities, working to solve health problems, enhance patient care and improve quality of life for patients. Interactions with industry are essential to bringing the researchers' discoveries to the public, but can present the potential for conflicts of interest related to their research activities. Click here to view a listing of instances where Cleveland Clinic has identified a Public Health Service (PHS)-Reportable Financial Conflict of Interest and has put measures in place to ensure that, to the extent possible, the design, conduct and reporting of the research is free from bias.

* Cleveland Clinic physicians and scientists subscribe to the guidance presented in the PhRMA Code on Interactions with Healthcare Professionals and the AdvaMed Code of Ethics on Interactions with Health Care Professionals. As such, gifts of substantial value are generally prohibited.

Patient Satisfaction Reviews

367 Patient Satisfaction Reviews

The Patient Satisfaction Rating is an average of all responses to the care provider related questions shown below from our nationally-recognized Press Ganey Patient Satisfaction Survey. Patients that are treated in outpatient or hospital environments may receive different surveys, and the volume of responses will vary by question.

Responses are measured on a scale of 1 to 5 with 5 being the best score.

The comments are submitted by patients and reflect their views and opinions. The comments are not endorsed by and do not necessarily reflect the views of Cleveland Clinic.

Overall Star Ratings
4.9 out of 5
Explains 4.9
Listens 5
Courtesy, Respect & Concern 4.9
Knows Medical History 4.9
Time Spent with Patient 5
Patient Rating of Doctor 4.8

77 Patient Comments

Reviewed on Apr 26, 2019

Dr. Mulligan is the best doctor I've ever had. He always takes time to listen to me and explains medications thoroughly.

Reviewed on Apr 16, 2019

Dr Mulligan was great. He spent time explaining my condition and answered all my questions.

Reviewed on Apr 10, 2019

I really like Dr. Mulligan. He is never in a hurry. He listens to all of my input and considers each one. Started on a new insulin and he provided a chart on dosages. He was very thorough in making sure I understood everything.

Reviewed on Apr 10, 2019

Dr.Mulligan was recommended to me by a 3rd party. Dr. was courteous and spent time with myself and husband explained everything clearly

Reviewed on Apr 10, 2019

Dr. Mulligan is one of the best doctors I have ever known. He's very knowledgeable. He listens to my concerns, gives me feedback on treatment that may or may not have worked and is just an all around nice person. I have recommend him to several people who suffer from the same affliction as I do.

Reviewed on Apr 8, 2019

simply the best Dr. I have ever had!

Reviewed on Apr 8, 2019

Dr Mulligan was thorough, caring, and kind.

Reviewed on Apr 4, 2019

Very good. Dr. Mulligan is very thorough, helpful, and informative. Always a pleasant experience.

Reviewed on Apr 4, 2019

Dr. Mulligan IS THE BEST!! What a caring,wonderful human being!

Reviewed on Mar 22, 2019

Dr. Mulligan is very good and thorough and he treats me as an individual with unique needs and not a one size fits all approach other hospitals and care givers have done.

Reviewed on Mar 14, 2019

Dr Mulligan is fantastic. if I had a question or a concern he addressed every question with a very easy to understand answer. he spent time explaining why and how we were going to address each issue.

Reviewed on Mar 11, 2019

Cannot say enough good things about Dr. Mulligan's knowledge, presentation skills, and allowing enough time to answer all my questions and explain things thoroughly to me.

Reviewed on Mar 11, 2019

I don't mind waiting because I know Dr. Mulligan is going to answer all my questions without rushing me.

Reviewed on Mar 6, 2019

Dr. Mulligan is very nice professional and extremely caring. I have recommended him to others as well. He spent time with answered my questions and concerns completely.

Reviewed on Mar 4, 2019

having dealt with insensitive endocrinologists in the past, dr. mulligan was a welcome and refreshing reprieve that eased my anxiety about this type of visit, and did not make me feel like my issues were 100% my fault. I cried several times because l was happy to feel seen and heard. he is a very kind man.

Reviewed on Feb 28, 2019

Dr. Mulligan always takes the time to listen to my concerns and makes sure that all of my questions are answered and that I understand everything discussed during my visit.

Reviewed on Feb 26, 2019

I would recommend Dr. Mulligan to anyone looking for a great Endocrinologist. he is smart smart, articulate and answers all my questions before I ask them.

Reviewed on Feb 25, 2019

Provider listened to my concerns and provided information on how to understand condition. I was given information to recon tact him if any concerns occurred in future. I would recommend provider to anyone needing similar treatment.

Reviewed on Feb 19, 2019

I haven't had any bad experiences with Dr Mulligan. He is literally THE BEST doctor I've ever seen. He looks outside the box for solutions. I hope he never leaves the Clinic!

Reviewed on Feb 19, 2019

I have recommended Dr Mulligan to several of my friends who need a good endocrinologist who actually listens to their problems and concerns. He is the best.

Reviewed on Feb 18, 2019

Dr. Mulligan is extremely thorough and compassionate. He is clear in his explainations and takes your input into account when making changes to care plans. He is the best doctor I have ever worked with.

Reviewed on Feb 14, 2019

I appreciated the time and attention Dr. Mulligan gave me to understand my diagnosis and how to manage it. I felt very comfortable moving forward.

Reviewed on Feb 13, 2019

The doctor was very compassionate and helpful

Reviewed on Feb 6, 2019

Doctor Mulligan is very thorough and answers any questions.

Reviewed on Feb 4, 2019

He is a fantastic Doctor, well worth any wait, because I know when he is with me, he is totally focused on my medical issues. I never feel rushed.

Reviewed on Feb 1, 2019

I always recommend Dr. Mulligan to people, he is an EXCELLENT doctor, who listens to his patients, and puts their wellbeing first.

Reviewed on Jan 23, 2019

Wonderful experience! Dr. Mulligan is the best doctor I have ever been to. He left no questions left unanswered and fully explained everything. He is a very thorough doctor and I would highly recommend!

Reviewed on Jan 23, 2019

wonderful doctor!

Reviewed on Jan 22, 2019

this was a very good experience. the doctor was very thorough in his exam. very satisfied

Reviewed on Jan 17, 2019

Dr. Mulligan is a fantastic listener. he explained everything to me in a kind, down-to-earth way and really seemed to care about my situation.

Reviewed on Jan 9, 2019

Dr Mulligan is super busy. Have to wait at least 4 months to reschedule an appointment

Reviewed on Dec 19, 2018

This was the first time in a long time where I felt a doctor really listened to me. Prior to seeing Dr. Mulligan, I had been seeing just my general physician for my issues and felt very blown off. Dr. Mulligan listened and asked questions and seemed to take an interest in what he could do to help me.

Reviewed on Dec 14, 2018

I had to wait over an hour to see Dr. Mulligan. I love Dr. Mulligan. He is very nice, very responsive, and very caring. I am not sure what happened, but to have an appointment at 10:25 in the morning and to already be an HOUR behind with your patients is just ridiculous. Dr. Mulligan was very apologetic. However, that does not make up for the fact that I had to make additional arrangements with my employer since I was missing an extra hour of work. It was quite an inconvenience in my day.

Reviewed on Nov 15, 2018

Dr. is thorough, knowledgeable and interested in listening and educating. One of the best Doctors I have ever been to!

Reviewed on Nov 7, 2018

Dr came in after nurse did preliminaries.

Reviewed on Nov 6, 2018

sometimes my wait to see dr mulligan is a little long once i get into the examination room. but i love my doctor he is understanding and he listens to me

Reviewed on Nov 6, 2018

Dr. Mulligan is amazing! I wish more drs were like him. He listens and he really wants for me to feel good.

Reviewed on Nov 6, 2018

I would wait as long as it takes to see Dr. Mulligan. i know he is giving the same attention to the person ahead of me and I appreciate that.

Reviewed on Nov 1, 2018

Always an excellent experience when I see Dr. Mulligan !!

Reviewed on Oct 30, 2018

Dr. Mulligan is a great doctor...never feel rushed

Reviewed on Oct 30, 2018

need more doctors like him, that is why I travel an hour to see him

Reviewed on Oct 26, 2018

Dr. Mulligan spends time with me and does not make me feels hurried or rushed. He is concerned and is knowledgeable about my medical care.

Reviewed on Oct 11, 2018

Dr. Mulligan always listens to what I have to say. I never feel rushed during an appointment and I leave knowing he listened to everything I had to say. He also explains things so I understand them and discusses every option for my care with me.

Reviewed on Oct 10, 2018

Dr. Mulligan is pleasant and always willing to discuss treatment options and timing with me. I value his expertise and approachability.

Reviewed on Oct 10, 2018

I waited about 25 minutes in the exam room to see Dr. Mulligan. This wait is not bothersome to me because he is generous with his time, conversation and discussions with me.

Reviewed on Oct 10, 2018

Dr. Mulligan is an amazing caregiver. He listens intently and always answers every question or concern that I have. He provides thorough explanations and consistent follow-up.

Reviewed on Oct 9, 2018

Despite the fact that Dr. Mulligan's office is over an hour's drive for me, his technical expertise and the level of care he provides are exceptional. He is the first doctor I have met at The Cleveland Clinic who listened to my concerns and explained a thorough treatment protocol. I would recommend him highly to anyone seeking care for hypothyroid disease.

Reviewed on Oct 2, 2018

Dr. Milligan is wonderful. He listened to all of my concerns and wanted extensive background information to inform his diagnosis and treatment. I normally am adverse to doctors, but Dr. Milligan is one I like and would recommend.

Reviewed on Sep 26, 2018

Everything went very well. I got appropriate answers to all my questions and Dr. Mulligan and his staff were very helpful. I would recommend him to anybody.

Reviewed on Sep 26, 2018

Dr Mulligan and his staff are great.

Reviewed on Sep 19, 2018

i luckily got scheduled with this provider because I called same day appointments. I had a question regarding treatments and the staff told me I could not get an appointment for another 5 months initially. I had a question that needed follow up because I became pregnant and luckily I knew to call same day appointments and luckily one was available that worked with my schedule. mychart messaging is also ineffective.

Reviewed on Sep 19, 2018

Dr mulligan is SO thorough and spent much time with me and my husband to discuss treatment. His skill and guidance are much appreciated and I feel at ease in his care.

Reviewed on Sep 18, 2018

I arrived for a 7:30 appointment. Was seen by nurse at @ 8. Doctor came in to exam room at @ 8:10. My total visit was about 50 minutes.

Reviewed on Sep 6, 2018

Dr Mulligan is a great doctor. the time it takes to get an appointment with him is worth the wait! He explains everything very thoroughly and answers every question. I like the fact that he really involves the patient in your own care and lifestyle changes.

Reviewed on Aug 30, 2018

concerning getting an appointment--Dr.Mulligan must be booked way ahead....

Reviewed on Aug 30, 2018

Dr. Mulligan gives such wonderful attention, I'mhappy to wait!!!

Reviewed on Aug 24, 2018

I mentioned to Dr. Mulligan that his approach to my problem was truly appreciated. He made the path to curing my hypothyroidism enjoyable.

Reviewed on Aug 13, 2018

My experience with Doctor Milligan was truly exceptional, as He clearly showed me the results of my ultra sound , explaining his course of treatments for me.

Reviewed on Aug 13, 2018

I have complete confidence in the ability of Dr. Mulligan to guide me along the path of health issues my Lord has presented to me.

Reviewed on Aug 13, 2018

after my experience of the thoroughness Dr. Mulligan spent during my exam listening to me descfibe my symptoms, I did not mind waiting , aware of his commitment to respecting his patients.

Reviewed on Aug 3, 2018

Dr. Mulligan and his nurse Ingrid are the best. She remembers who we are and will ask about things that helps us feel like we are important. Dr. Mulligan always is a good listener and always seems very up on new medications etc

Reviewed on Jul 26, 2018

Dr. Mulligan is an outstanding physician.He listens and has a pleasant personality. I never had the feeling I was being rushed.He seemed sincerely interested in helping me.

Reviewed on Jul 24, 2018

The doctor and nurses explain everything very clearly...

Reviewed on Jul 23, 2018

Dr. Mulligan and his staff are a joy and a pleasure to work with. I owe my continuing recovery from Hypopituitarism and secondary adrenal failure to Dr. Mulligan.

Reviewed on Jul 20, 2018

Dr. Mulligan is the BEST doctor at the Cleveland Clinic! He is the benchmark that the organization should use to define what World Class Health Care looks like.

Reviewed on Jul 20, 2018

Dr. MULLIGAN explains everything to you in a way you can understand it. very nice Dr. Never had any problem with him.

Reviewed on Jul 18, 2018

Dr Mulligan wanted my next appointment to be in 3-4 months and the first available was December 24th. I did have the option to see a practitioner, I opted to wait to see him due to the fact that we drive about an hour for these appointments.

Reviewed on Jul 18, 2018

This was my second visit with Dr Mulligan and both times I left the appointment with new knowledge and ideas about managing my disease. I do not leave the appointment overwhelmed with thoughts of how am I ever going to manage this problem.

Reviewed on Jul 17, 2018

waited 4 hours before appointment never checked in by desk after informing them I was early. then I waited almost an hour for the doctor

Reviewed on Jun 27, 2018

Dr. Mulligan is one of the best doctors I have ever worked with. He listened very directly to what i was saying and never doubted my experiences or thoughts regarding my health. He was incredibly knowledgeable and was very willing to to extra research to be able to answer some of my complex questions about some of my medications. I already recommended to several friends.

Reviewed on Jun 25, 2018

Dr. Mulligan was very kind and listened closely when I talked about my health problems. He wanted to know any and all information I could offer to aide in his treatment plan. He never interrupted me, belittled my views, or rushed me out. I want to continue to see him as my doctor.

Reviewed on Jun 21, 2018

Dr. Mulligan was very patient, caring and informative in dealing with me. He went above and beyond what most doctor's do. My experience with him was excellent.

Reviewed on Jun 20, 2018

Dr. Mulligan is very thorough and does not "rush through" my appointments.

Reviewed on Jun 15, 2018

Dr. Mulligan is professional, thorough and is a pleasure to see. Always has the patients best interest at heart. He is top notch.

Reviewed on Jun 13, 2018

Dr. Mulligan is very kind and easy to understand and was very patient and listened very well

Reviewed on Jun 12, 2018

I trust Dr Mulligan very much. I believe he is concerned about my health. CCF should work to get more doctors like him

Reviewed on Jun 5, 2018

Dr. Mulligan takes as much time as I need to speak with me, so I do not mind if he runs late on his appointments, because that means he is taking his time with his patients. He is a kind and caring physician that I have recommended to family and friends!

Related Videos Featuring Guy Mulligan, MD

Related Videos Featuring Guy Mulligan, MD

Back to Top