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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
  • Diabetes - Management
  • Fine Needle Aspiration
  • General Endocrinology
  • Male Infertility Testing
  • Medical Weight Management
  • Radioactive Iodine Treatment
  • Thyroid Aspiration
  • Thyroid Ultrasound
  • Thyroid Ultrasound and Biopsy
View all 11 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, 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
  • Metabolic Bone Disease
  • Metabolic Diseases
  • Metabolic Syndrome
  • Osteopenia
  • Osteoporosis
  • Panhypopituitarism
  • Parathyroid Disease
  • 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 64 Specialties +


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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 1/4/2023, 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

436 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
Courtesy, Respect & Concern 4.9
Patient Rating of Doctor 4.9

102 Patient Comments

Reviewed on Aug 24, 2023

Dr. Mulligan is very thoughtful and calm with his words. He does a thorough job, contacts with test results in a timely manner and overall is an excellent doctor. I am very happy he was recommended to me from another family member.

Reviewed on Aug 24, 2023

Dr. Mulligan speaks to you as if you are a friend, not a patient or paycheck. He is very understanding of one's feelings and concerns. He explains things in a way that anyone can grasp understanding.

Reviewed on Aug 24, 2023

Dr. Mulligan was very good about providing me with information about a couple of options with new medications

Reviewed on Aug 24, 2023

Excellent provider and always taking the time and listen and show care even in a fast pace medical field and lot of patients to see but from the 1st in 2019 and present and I am thankful to find Mulligan and always taking the time putting patient first. Thank you so very much and it mean much to patients

Reviewed on Aug 23, 2023

It took years to finally find a doctor that listened to my concerns, Dr Mulligan listened & addressed them.

Reviewed on Aug 21, 2023

Dr. Mulligan is excellent. He listens and cares about me. This was my first virtual appointment. It was just like an in office.

Reviewed on Aug 18, 2023

Excellent doctor

Reviewed on Aug 18, 2023

Excellent doctor

Reviewed on Aug 14, 2023

I was extremely impressed with Dr. Mulligan's genuine caring attitude. He listened completely and thoughtfully discussed every issue and concern without feeling rushed in any way. The experience was very relaxed yet professional.

Reviewed on Aug 14, 2023

I can't say enough good things about my impression of Dr. Mulligan during my initial telemed experience.

Reviewed on Aug 10, 2023

Doctor was wonderful and took his time explaining details and I did not feel rushed through my appointment. Great experience.

Reviewed on Aug 9, 2023

The doctor listen to my concerns and put in writing a detailed plan to help me maintain my sugar levels.

Reviewed on Aug 9, 2023

Very Professional as well as staff. He answered all my questions and everyprocess that he had on paper was completed just as was written. Thus gave me some peace about having the procedure done. 5hank you Dr. Mulligan and staff

Reviewed on Aug 9, 2023

Dr Mulligan is always friendly, professional, always explains any changes, if needed.

Reviewed on Aug 8, 2023

Dr M is a model for care. He listens and helps me consider options od increasing medication while balancing side effects. He helps write for bloodwork and renewals to keep care maintaining my prescriptions and labs without needing to do extra calls before subseeuent visits. He considers both the medical decisions and the processes involved to make it easier for me.

Reviewed on Aug 7, 2023

Dr Mulligan truly cares for his patients. He listens and works to meet your concerns. I am so grateful he was my doctor and he devised a protocol for me that is actually working to a remission of the medication.

Reviewed on Aug 7, 2023

Dr Mulligans staff is very efficient and friendly

Reviewed on Aug 7, 2023

My Physician was awesome. Great job explains all of my options and treatment plan. Very good follow up.

Reviewed on Jul 28, 2023

Dr. Mulligan listen and was genuinely interested in my health needs. I look forward to a long standing relationship with him as my doctor.

Reviewed on Jul 27, 2023

Doctor spent appropriate amount of time to learn my medical problems and discuss alternative medicines. I was very impressed with his professionalism and patient caring.

Reviewed on Jul 19, 2023

Dr Mulligan is an excellent doc. Very knowledgeable, compassionate and spend much time explaining a new med. Greatly appreciate his professionalism and kindness

Reviewed on Jul 5, 2023

Unable to get an appointment within a reasonable time again if it is cancelled for some Reason by physician or patient

Reviewed on Jul 5, 2023

Excellent care provided by Dr Mulligan

Reviewed on Jun 27, 2023

Dr. Mulligan always takes the extra time to listen, and offers valuable advice. It is always a pleasure to see him!

Reviewed on Jun 9, 2023

Dr. Mulligan is excellent and very thoughtful.

Reviewed on Jun 9, 2023

Dr. Mulligan is always so kind and does his best and helping me with my diabetes. He listens with no judgments.

Reviewed on Jun 9, 2023

Dr. Mulligan really listened and understood my situation and made changes to my meds and explained it to me that made sense.

Reviewed on Jun 8, 2023

Dr Mulligan listens very well and fully explains the options I have for my care.

Reviewed on Jun 2, 2023

The provider never appeared for my visit. I provided from the time I entered (8:53) to the time I exited (9:26).

Reviewed on Jun 2, 2023

Dr Mulligan always answers my questions and concerns very well

Reviewed on Jun 1, 2023

Dr Mulligan does not rush to finish the appointment. He discusses and answers all my questions

Reviewed on May 24, 2023

Dr. Mulligan is Such a great doctor, I will wait to see him

Reviewed on May 24, 2023

Dr. Mulligan answers your questions and spends time and listens to your concerns and makes sure you understand all the options. I have recommended him many times!!

Reviewed on May 19, 2023

Dr. Mulligan's office called me to schedule the appointment. That is very much appreciated.

Reviewed on May 17, 2023

I truly enjoyed my visit w Dr.Mulligan. He is kind, attentive, patient, thorough & was very informed about my case meaning he did research prior to seeing me for the first time. I was unable to see Dr. Mehta because is only seeing inpatients now due to personal reasons. I was very sad about that as he's an excellent doctor but, after meeting & getting to know Dr. Mulligan, I feel I'm in great hands once again. I look forward to many pleasant future visits w him. Thank you for providing excellent care.

Reviewed on May 17, 2023

Dr. Mulligan is Excellent! *********** Many stars for him.

Reviewed on May 16, 2023

This provider has always treated me with kindness and professionalism. Very easy to talk to, listens. Probably the most compassionate provider I have had!

Reviewed on May 9, 2023

*Dr. Mulligan is FANTASTIC most attentive dr. I have ever met. Literally the only negative is that he is a part of the Cleveland Clinic and the rules of their joke of a management group.

Reviewed on Apr 24, 2023

I really like this provider. He has a lot patience and he's not hurry through my appointments. He always takes his time with me.

Reviewed on Apr 18, 2023

Dr. Mulligan takes the time to review and explain test results and recommend next steps in treatment plan. Appreciate his manner and thoroughness.

Reviewed on Apr 13, 2023

Tried to make an appointment for the beginning of October, 2023 when I left Dr. Mulligan's office, andwas told I would have to wait until the following Monday as all dates were filled. Had to call back on the following Monday. Felt that was an inconvenience.

Reviewed on Apr 5, 2023

Dr Mulligan is an excellent Provider. He listens thoroughly. He is kind, polite, and professional. He truly listens and goes the extra mile to be certain you understand your condition and to answer all questions. He makes appropriate recommendations and treated me as an Individual. Quite respectful. I would recommend Dr Mulligan. If I were able to note a response higher than a 5, I would.

Reviewed on Apr 5, 2023

Dr Mulligan is a wonderful doctor. He is kind, supportive, and nonjudgmental. I've experienced other doctors who have an undercurrent of judgemental about weight. Dr Mulligan is always supportive and encourages without judgement. I really appreciate him.

Reviewed on Apr 3, 2023

Dr. Mulligan is very receptive to my concerns.

Reviewed on Apr 3, 2023

Couldn't ask for a better doctor. He is caring, professional, wants to truly make sure he understands and offer the best care!!

Reviewed on Mar 30, 2023

Dr. G Mulligan was very kind, listened and explained test results and future steps.

Reviewed on Mar 30, 2023

Dr Mulligan and his staff are always caring, respectful and courteous. Dr Mulligan always takes the time to go over everything with you

Reviewed on Mar 28, 2023

Dr. Mulligan was very respectful and showed a willingness to involve me as the patient in making decisions.

Reviewed on Mar 27, 2023

Virtual visits are good for me and I am glad Dr. Mulligan can do them.

Reviewed on Mar 24, 2023

We need to clone Dr Mulligan. He is such a great doctor but so hard to get an appointment with him. However I would not want to see any other doctor.

Reviewed on Mar 23, 2023

Love Dr. Mulligan's attention to detail. Always ready to explain every detail of test results.

Reviewed on Mar 23, 2023

Dr. Mulligan is a nice man and forthright. My primary care physician made a general recommendation and I already had a general idea of what I wanted, Dr. Mulligan quickly considered all of the information and came up with a reasonable and prudent plan of action.

Reviewed on Mar 21, 2023

This was the best doctor office experience, I didn't have to wait long, check in was easy and the doctor actually listened to my concerns

Reviewed on Mar 13, 2023

Dr. Mulligan was fantastic. He addressed my concerns directly and immediately, and the labs that he ordered quickly revealed a problem that MULTIPLE other doctors have overlooked and, if left undetected, would have caused me months of failed treatments and considerable distress as well as potential severe disease in the future. I am so grateful to him!

Reviewed on Mar 13, 2023

I am very thankful for Dr. Mulligan.

Reviewed on Mar 13, 2023

I'm fortunate to have Dr. Mulligan as my endocrinologist. Clinically I think he's at the top of the game clinically; he listens carefully, is patient with questions, and gracious to patients.

Reviewed on Mar 9, 2023

Dr Mulligan is one of the best physicians that I've ever experienced. He is so caring, kind, and attentive. I feel so blessed and grateful to have found him.

Reviewed on Mar 9, 2023

Dr. Mulligan is very difficult to get an appointment with. But he is worth the wait.

Reviewed on Mar 9, 2023

Dr. Mulligan is the best.

Reviewed on Mar 7, 2023

Dr mulligan is the best

Reviewed on Mar 7, 2023

He is a great provider.

Reviewed on Mar 6, 2023

Dr. Mulligan was attentive to my needs and very knowledgeable of what I needed in terms of testing.

Reviewed on Mar 3, 2023

He is an excellent Doctor and seems very caring and takes his time but it's hard to physically get in to see him.

Reviewed on Feb 24, 2023

Dr. Is wonderful and cares about you !!!!!!!!!!

Reviewed on Feb 23, 2023

Very good doctor and so happy that he takes his time with patient

Reviewed on Feb 15, 2023

Dr. Mulligan is very thorough and answers my questions.

Reviewed on Feb 13, 2023

Dr mulligan and his office are very busy, yet i'm never rushed and receive great follow up from all involved.

Reviewed on Feb 10, 2023

Dr. Mulligan is brilliant and an amazing Doctor.

Reviewed on Feb 8, 2023

Dr Mulligan is always very attentive, professional, and kind. He always answers all of my questions. Together we discussed and agreed to my Treatment Plan. I truly appreciate his Wonderful Care.

Reviewed on Feb 3, 2023

Very pleased with the video visit for ease & timeliness so that further testing could be completed quickly & treatment started asap.

Reviewed on Feb 2, 2023

Dr.Mulligan is a caring, think outside the box wellness focused doctor. I'd highly recommend him to anyone needing his expertise.

Reviewed on Feb 1, 2023

Dr. Mulligan is the best! He listens to the patient and explains things very well. He explains test results in great detail and engages the patient to participate in learning and understanding the disease.

Reviewed on Feb 1, 2023

Everyone was very prompt and punctual on my appointment and scheduling. The doctor was very considerate and knowledgeable on my condition.

Reviewed on Feb 1, 2023

The doctor was very kind and considerate. Explains everything very thoroughly and answered all questions.

Reviewed on Jan 31, 2023

God found this wonderful doctor for me. He was so humble, smart and caring. I appreciated him sitting down and explaining my condition in detail. He showed concern and compassion. Respect that this is my body and allowed me to know what is happening to me. I completely respect and appreciate him.

Reviewed on Jan 31, 2023

Dr Mulligan is always very thorough and encouraging.

Reviewed on Jan 30, 2023

Doctor Mulligan is Excellent! I'm very happy with his expertise and professionalism.

Reviewed on Jan 25, 2023

As always, Dr mulligan addressed all of my concerns and explained every issue in understandable detail. I am following all recommendations and seeing positive results already! Positive results from our discussion and better understanding of my condition.

Reviewed on Jan 25, 2023

I am very satisfied with Dr Mulligan

Reviewed on Jan 24, 2023

This Dr is high in demand, however scheduling at the Cleveland Clinic is always very professional and courteous. I ended up getting in much earlier than scheduled because I was put on the call waiting list for cancellations. This is an excellent service you offer

Reviewed on Jan 20, 2023

Very good experience doctor listen to my concern.

Reviewed on Jan 18, 2023

Dr. Mulligan is one of the few providers that actually listened to my concerns and took the time to explain things to me.

Reviewed on Jan 17, 2023

Dr Mulligan is very thorough. We highly respect his advice.

Reviewed on Jan 9, 2023


Reviewed on Jan 4, 2023

Dr. Mulligan is a very caring and respectful physician who listens to my concerns. What a great doctor... I am lucky to have found him.

Reviewed on Dec 30, 2022

My experience has been great. I would highly recommend the physicians at Cleveland clinic.

Reviewed on Dec 29, 2022

I love my doctor because he listen to me and what problems that I have. He is always nice and well spoken. I will follow him to any hospital as long it in Ohio

Reviewed on Dec 27, 2022

Dr. Mulligan is the best...he is attentive ,concerned and takes his time.

Reviewed on Dec 27, 2022

I had an involved question about the function of my insulin pump. Dr. Mulligan addressed the problem and explained what he did to remedy what he did to change settings and fix the issue.

Reviewed on Dec 23, 2022

Dr. Muligan is awesome

Reviewed on Dec 20, 2022

Dr. Mulligan is the best.

Reviewed on Dec 13, 2022

Doctor Was Polite and Very Easy To Understand When Describing My Condition

Reviewed on Dec 13, 2022

Doctor Provided An Overview Of Medical Condition and When One Aspect Was Discussed, I Was Given A Clear and ConsiceResponse

Reviewed on Dec 2, 2022

I have had many doctors, the best being my oncologist Dr. Dergham. Dr. Mulligan showed the same empathy and care. He never made me feel bad about my weight or lifestyle choices.I am really looking forward to working with him.

Reviewed on Nov 22, 2022

Excellent doctor and staff!

Reviewed on Oct 5, 2022

The best doctor I have! He listens. He diagnoses accurately. The plan of care is a mutual decision. It is then put into writing in notes given to me at the conclusions of the appointment after we both look at it and go over the print out. So very helpful to keep patients complainant thru clear concise directions.

Reviewed on Oct 5, 2022

Care by Dr Mulligan has been efficient for access to appointments and my chart messages.

Reviewed on Oct 4, 2022

Excellent visit, Dr. Mulligan was very attendant to my concerns and took the time to discuss options.He didn't rush the appointment and made sure we were on the same page as to finding a solution.

Reviewed on Sep 27, 2022

Listened to all my problems. First face to face since Dr. Mehta left. Explained labs very thorough.

Reviewed on Sep 23, 2022

I've been through a half dozen endo's - I've had issues with staff & doctor alike... I've had NONE here.

Reviewed on Sep 19, 2022

Dr. Mulligan is amazing! He's very knowledgeable, understanding, and very easy to talk to and discuss things with.

Reviewed on Sep 16, 2022

Dr. Mulligan took time to explain insulin resistance and some meds to help me overcome it and get back on track. I really appreciate the time he took with me to explain these things even though I am a nurse. He did not assume that I may have knew already information and went in depth into how insulin works in the body and over the medications and supplements that we might be able to use to help me improve.

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