My mom's side of the family has been struggling with numerous auto-immune diseases for generations now, and unfortunately I have inherited them as well. Yes, Dr. Marcus doesn' take insurance, but he is worth every single penny for anyone with auto-immune seeking answers to all our mystery illnesses and symptoms that no other doctor has been able to explain. Finally I'm getting the answers I need and the instructions/ medications to be able to have a life again, a life not stoeln from me by constant fatigue and mounting diagnosises. Highly recommmended! read more

Dr Marcus is brilliant the best ever! He is able to dx anything and treat it even the most unique medical conditions!

Excellent care and helped me get through myocarditis when other doctors didn't prescribe anything. Dr. Marcus seems to be very preventative which I prefer. Treat potential complications prior to waiting for them to arise. read more

As others have mentioned, they don't accept insurance. Initial visit is $400, $200 each after that. While not ideal, I was okay with this because I want to get to the bottom of my issue. Trying to schedule an appointment is very difficult. I requested a phone call and they emailed me instead - I responded with a simple question and never got a response. I followed up again to ask for an appointment and they gave me a list of times - I selected one, and they responded "that time is taken" and nothing else...I responded within one hour of the email listing that time as available and they did not re list available times. Each email was unprofessional and rude. I'll put up with a certain amount of this to get the best doctor, but it's an indication of how the overall experience will go so I will seek a different doctor. At $400 for an initial visit I expect the front desk staff to at least not be rude. read more

Dr. Alan Matcus began as my wifes Diabetic Dr. In the spring of 1989. He first tested the condi t ion of her Diabetis as she wasa was out of of control. He immediately started her wellness therapy. I c a led him eve r y day at 6:25 am to report th er results of her previous days test as and would tell me h r r lnsulin dosage for that day. After 6 weeks of this a schedule, he installed an insulin pump. The results were life changing. ​Richard Lull 720 917 8512. Many more ex as males of this miraculous dedicated Dr. read more

Dr Marcus does not take insurance and charges $400.00 for the first visit and then $250.00 for follow up visits. So disappointed- he will only help the few that have money. I guess I have to keep Searching for a doctor who cares about patients health and not his pocket ! read more

Dr Marcus was referred to me by my Insurance agent, Ashley Clark. She drives down from North LA to see him and has for years. He's personable, cares a lot about me as a patient and is this side shy of a savant in Endocrinology. He read a prior blood panel I brought with me and named off 7-10 ways of feeling I must be experiencing due to what my blood told him. Including no sex drive due to me taking too much testosterone. My husband concurred! He even made a zoom call for me Saturday morning of Mother's Day weekend at 7:00 to calm my fears. He responds to all my emails, quickly. He's caring, knowledgeable and direct. I have Thyroid Eye Disease and he quickly got me into an IV infusion program that's helping where I though there was little help, he put me on a glucose monitor, recommended 17 different diagnostics and doctors to support my journey. I have now found multiple friends that go to him. I highly recommend Dr Marcus:) read more

I called Dr. Marcus's office to make an appointment for my daughter today and I was told by the phone assistant that he does not accept any insurance and his first visit is $500 and follow-ups are $250!!! read more

I absolutely have the utmost respect and faith in Dr. Marcus. He is so knowledgeable in the field of pre diabetes/diabetes and a great doctor. I can't say enough good things about him. Disclaimer.....He does not except insurance, however he is 100% worth every penny my health is worth it! read more

Dr. Marcus saved my father's life. In 1995 my Dad was given less than a year to live. His liver was bad and his iron levels were through the roof. Dr. Marcus took my Dad on as a patient and has kept him alive. My Dad got to live and see his daughters get married and all 4 of his grandchildren born. My Dad is far from healthy but Dr. Marcus has kept him alive. You may not like his front office staff but we have seen some of the amazing people he has employed over the years. So just because you may not like his staff don't disregard Dr. Marcus' talents. His thinking outside of the box gave me my Dad. read more

I've still been seeing Dr. M since my last review in 2016...He's amazing. He's become a confidante, and trusted advisor, for all my medical concerns. I feel like he knows my history and understands me, and (now my significant other, who also has seen him for the past 10 years). He has a wonderful bedside manner, and truly cares about his patients, and it shows. I have so much trust in him, and would be completely lost without his care. The care regimen over the course of years (which has changed as I've gotten older), has changed my life so many times over and over. First, not knowing I had hypothyroid, and he gave me medication and it was a Game-Changer. And again, recently, for other personal issues I needed help with as I've grown older. I literally CRIED when I started to see changes in myself, as a result of his recommendations/care. I have so many friends I've referred to him over the years, who also still see him religiously. One of my close girlfriends (who first introduced me to Dr. M over 15 years ago), still goes to him, even though she moved to Florida. He will do phone consults when needed. He's great! read more

Dr Marcus is definitely the best doctor you can possibly have. I am someone that has a lot of knowledge about medical field and there is not better Endocrinologyst in California. He is also my primary physician now. I mean ever body in my family sees Dr Marcus. And as busy as he is, he always spends a lot of time anytime we visit him. By the way, you can do your blood work at his office at the same time. How much time that saves. Omar is a lab technician is awesome. Highly recommend. read more

Could a Dr be worst than Dr Marcus, less caring and more ignorant than Dr Marcus!!! "NO" I met Dr Marcus Dec 17th 2021, with flu like symptoms but no flu or Covid. He misdiagnosed me , put me on medication that caused fever until I got a second opinion an stopped his medication. He sent me to ER (imagine the cost of ER visit I have to pay) for just a fever during Covid, while I had already been to ER once before. The doctor at the ER told me why would your dr send you to ER while there is covid, he suggested I get a second opinion and thank God I did! The worst part is, there is a test to confirm the disease he misdiagnosed me with, but he didn't want to do that test instead he wanted me to get a CT-SCAN of my whole body!!! Don't fall for the " this is my personal email and I'll get back to you in half hour" It is impossible to get a hold of him on a weekend, I had to call several times! He wanted me to have a full body CT- scan for a fever that turned out to be side effect of the wrong medicine he put me on. I won't say don't see him, I would say "RUN A WAY" I can't imagine where I would be now If I didn't switch doctor. And when I asked him for my medical record, he added stuff to my chart that I never said to cover himself for his misdiagnosis!!!! Once you get in , his staff never answers the phone, they only call you back so good luck having a question. Save your $400 and go to a Dr that knows what is doing! I was sick for 3 weeks, bed ridden and couldn't take care of my kids because he made a mistake! Dr Marcus, Keep the $400 and donate it to a charity!!! Hopefully I am saving lives steering people away from your practice. read more

This doctor doesn't accept any insurance! Unheard of you have to pay 100 percent out of your pocket! I give him a big Zero. So sad to see a doctor practice like this, what if a someone needs a surgery? I think these five starts given by his relatives read more

After reading the review of Dr. Marcus, I was actually excited to reach out to the office to make an appointment. I have been trying to get in touch with the office for almost a month and half but all I receive when I call is their voicemail system. I have left several messages but no on has ever responded to any of them. I don't know if the office is still in business, or if they are no longer taking new patients or if no one truly cares. If they are no longer taking new patients, I understand this happens with practices but the courtesy of a return phone call to let me know this would be nice. Very disappointing customer service so far. read more

Absolutely love dr Markus! I am blessed! I fell supported by him! He is truly amazing!

If you are tired of visiting your doctor and feel like they do not hear you, make an appt with Dr. Marcus. He will help you get to the bottom of your health issues and provide the support you need while doing so! read more

Where has Dr. Marcus been all of these years. Or rather, where have I been?! If only I had started seeing him years ago, so much could have been prevented. If you're deciding between specialists for thyroid and autoimmune disorders, stop now. Dr. Marcus is the one. His extensive knowledge in this very intricate field is a rare find, supported by his years of research and quality experience in the field. His quick and sharp ability to tie in a random symptom that you may have into your medical condition is a sight to be seen and something to be experienced - like someone solving a rubik's cube in front of your eyes after you and others have been trying for the longest time. I am so excited to have found a specialist who can finally help me (instead of making me feel worse as other "specialists" have due to their lack of expansive knowledge like Dr. Marcus'). I've already recommended several friends and family to see him. Looking forward to finally feeling better again with the help of someone who genuinely cares to help and doesn't just tell you what to do but wants to educate you to help you become your own personal health expert. As he will tell you time and again, "you will get better!" read more

Dr. Marcus goes above and beyond to explain what is going on with your body and to help you attain optimal health. I came in with a low thyroid and he insisted on checking my blood sugar despite my personal doubts that there could be an issue (I exercise and eat low carb). Well he had good reasons to check because he could see what I couldn't and was able to identify some serious issues which had been making me feel like a complete zombie in the afternoons. I have more energy that I've ever had and feel like a new person. I can't say enough good things about him. Amazing bedside manner and cares about his patients. read more

Diagnosed my Hashimoto's in a week. I've been searching for someone to help me for at least 6 years. He looked at my old labs and noticed things other doctors missed, asked all the right questions and then ran the right tests. I feel so relieved to finally have answers so I can work on feeling better. read more

My mother brought me in to meet Dr. Marcus in 1996. Her health had dramatically improved in the five years she had already been seeing him. Needless to say I have never left. In may of 1996 I was 450 lbs, sick & stuck. I truly needed medical help but was too emotionally decimated from years of physicians humiliating and demeaning behavior towards me. When I met Dr. Marcus, my life changed. I now had a true health partner who worked with me & didn't sit in judgement of me. And yes, while I have been able to let go of 200 lbs., Dr. Marcus is not "scale-centric". He taught me that weight is only one piece of information about my health. In the last two decades we have been through many ups and downs together. I know in my heart that I am so much better off for the experience of knowing him. I couldn't more highly recommend Dr. Alan Marcus. read more

I don't care what Dr. Marcus has done in his personal life, that doesn't effect how great of a Doctor he is. He's the only endocrinologist who has really sat and worked on finding solutions for me. He cares and that's what matters. When you see him, you feel like a person who matters. Google him all you want, but honestly does that make him a bad doctor? I will continue to recommend him and see him and thank him for his expertise in the field. read more

Dr. Marcus has been a life-saver for my family. My wife and I are Type 2 diabetics who have been treated by Dr. Marcus for over 20 years. In that time he has always made our health and happiness a priority. He is a great listener who has been very responsive any time we've had a health problem or symptom. He has been very proactive with my wife's health care, including guiding her through a high-risk pregnancy. He is always willing to work with his patients to find a healthy solution that the patient can maintain and does not push unreasonable expectations on his patients. Dr. Marcus has treated a number of people in my family and has played an integral role in our overall good health. Thank you!! read more

I came out of my first visit with Dr. Marcus today and have to say that he may be one of the best doctors I have encountered after years of working with medical practices. He took his time in explaining and educating and treated me as a who,e human being, explaining how the symptoms and conditions affect each other. It felt eye opening to me. I actually feel motivated and confident. He has great demeanor, the office is clean and well organized. Note that he is out of network for all insurance and worth the $400 cash payment for the visit. There is an independent lab to draw blood right on the premises. Stay tuned but I'm feeling positive! read more

Alan Marcus doesn't accept any insurance. The receptionist are rude. I never heard not accepting any insurance.

Dr. Marcus has completely changed my life and my family's. My entire family goes to Dr. Marcus and he has changed the level of health for all of us. I came to him about 4 years ago with countless issues and he addressed each of them and we are now only dealing with one. He was able to diagnose my brother in law after a lifetime of unanswered questions and misdiagnosis. He is a miracle and blessing to myself and my family. I don't know where we would be without him. His knowledge and compassion is boundless. read more

Dr Marcus has been my endocrinologist for 18 years. I came from most prestigious healthcare providers in Boston. Thank goodness my husband got transferred. Dr Marcus has not only saved my life but also extended it. He is aware of every study, medication and recommendation related to T1D. He is brilliant and is not afraid of trying new advances in T1D treatment. He completely reversed my kidney disease and the treatment he used is now followed by the rest of the country. But, he embraced it ten years prior than the conservative doctors who wait way too long at the expense of patients' organ health. My recommendation is for any person with T1D who is determined to live an active and healthy life to meet Dr Marcus. He educates patients and tries to create a partnership to battle this horrible disease together. I have had T1D for 39 years, have two teenage daughters (who are in perfect health thanks to him seeing me thru both pregnancies and births) and look like the healthiest person around. I tend to hate taking medication but have learned to trust Dr Marcus when he recommends it. My labs are perfect w no red flags only because I work with this brilliant endocrinologist. My husband is now seeing Dr Marcus for his own health issues and hopes of looking and feeling as great as I do. Of note, I worked in the diabetes industry for years prior to moving to California. I became acutely aware of how lazy and uninterested many endocrinologists are in learning about innovative diabetes treatment. There are amazing improvements in insulins and medicines. Dr Marcus knows them all! He wants our lives to be better so we can live longer. If u want the most updated treatments and are willing to work WITH a doctor instead of just being told blindly what to do than this is the practice for you. His office staff advocates for patients, labs are done easily in the office and the practice tries to make life easier knowing that living with T1D is an exhausting disease to battle. read more

BRILLIANT doctor. My husband (an MD) and I consider him to be the best endocrinologist, all around physician and person. He takes all the time needed to explain what he is thinking, why he is doing certain tests, explaining results and treatment options (if treatment is warranted). He makes sketches as he explains the multiple feedback loops of the endocrine system and organs that may be affected (kidneys, heart, brain, etc). read more

Ok, I'm going to tell you about in an incident that happened almost 20 years ago but it has changed my life. i went to see Dr. Marcus because my hormones were totally out of whack. Instead of listening to me, he did some crazy tests that tested my red/green perception and diagnosed me with "Relative Adrenal Insufficiency", which I now know is not a real disease. He prescribed corticosteroids and within 2 months my adrenals were crashed and my immune system was gone. I got a virus of unknown origin which I have never recovered from and now have Myalgic Encephalomyelitis. I am now housebound, but not bed bound (yet). There is no treatment or cure. Any doctor who might be able to help me slow the progression does not take insurance so everything is out of pocket. I will only get worse. I wrote to Dr. Marcus about this about a year into my illness and I never heard back. Google him and you'll see what he's been up to lately. read more

Overzealous drug pusher!! Everything prescribed by this doctor was retracted by multiple other physicians who claimed misconduct against Dr. Marcus. Furthermore, the staff are incompetent and unwilling to help their patients. Avoid south OC endocrinology at all costs. read more

If you are frustrated with the care you are getting, then you need to see Dr Marcus. I was in kaiser. I was told, yep you are diabetic and the classic " you need to loose weight". The problem was I was trying. I ate 800 calories a day just to not gain weight. Kaiser pretty much treated me like I was cheating and that's why I was unsuccessful. So my friend said to see Dr Marcus. Here it's a year later. I've lost 102 lbs. he's not magical. I had to make huge lifestyle and eating changes. But I'm healthier, happier. My A1c is out of kaiser' diabetic zone, although dr Marcus would say I'm still diabetic. I have 22 lbs to loose for kaiser to remove my skin. What makes dr Marcus work is that he keeps in contact with you. He's like you jiminey cricket. Knowing that I have to answer to someone, for me, keeps me pretty on track. I was and still am a skeptic on most things. But he's given me the hope and change I was looking for. It has to be the right time for you. And, you have to have motivation. My motivation is three kids that need me. Give her him a try when you are ready to put in the work. read more

Doctor Marcus is so thorough. He is patient kind and most importantly caring. He is not closed minded and can think outside the box unlike my Kaiser doctors. I left his office in tears because I finally felt like someone understood me and my health. Dr Marcus doesn't treat you like a lab value but rather a patient as a whole. He looks at every aspect of your health and how they affect each of your health conditions. He doesn't just aim to get your lab values into the normal range he wants you to be optimal and feel well. I cannot speak highly enough about this man. My wish is he will train someone to take over for him when he retires because our new physicians seem to be being trained by the pharmaceutical companies. I think many didn't go into the field to really heal but rather to just perform a job and earn a good living. I feel Dr Marcus strives to really heal and give his patients a better healthy life. He doesn't take insurance and he doesn't have to put up with insurance constraints. read more

About 3.5 years ago I was referred to Dr. Alan O Marcus, MD Endocrinologist by my dental hygienist. She was sure Dr. Alan O. Marcus could help me with my dry mouth which was causing a rapid deterioration of my teeth. At my first appointment at Dr. Marcus office, South Orange County Endocrinology. . . His front office was kind and respectful. I filled out some paperwork, thereafter the staff nurse took my vitals and placed me the exam room. Dr. Marcus introduced himself, asking me about my health concerns as he listened patiently. He spent a fair amount of time asking questions about my family history health. . . writing everything down; my father and a younger sister died of cancer. Two sisters had double mastectomies within two years of each other. Dr. Marcus ordered a gamma of blood labs, and including a ultrasound for nodule he found on my neck. A follow-up was scheduled to go over the results of the blood labs. He found I had an autoimmune disorder and vitamin D deficiency. The small nodule was nothing to be concerned about. He continues to monitor this nodule at each appointment examine. Also since cancer is so prevalent in my family, Dr. Marcus placed me on prevention therapy and gave me several articles from the medical journals regarding our discussion of my health. He prescribed the needed medications and ordered another round of blood lab test, a week before my next appointment (a month later). As Dr. Marcus continued to monitor my health, he found one of the blood lab resulted irregular (not normal). Dr. Marcus ordered I see a Rheumatologist. The Rheumatologist found that I had another autoimmune disorder and prescribed medication. I am monitored by this doctor every six months. Today, I feel better than I have in years. . . The knee stiffness, weight gain, fatigue, anxiety and stress was not due to old age, but was due to the autoimmune disorders. My health in under control and has been for quite some time. The last visit in recent days with Dr. Marcus was great. . . it's always great to hear my lab results are showing I'm healthy and well. My scheduled appoints have gone from once a month. . . to once every three months . . . and now I see Dr. Marcus every six months. In the past years, before Dr. Marcus, I felt I was spinning my wheel with the healthcare I previously had. I was unhealthy all along and the healthcare facility I was a patient of, put a bandage on the health issues and sent me on my way. Dr. Marcus found and solved my health issues along with his colleague. I don't even want to think about my health and where I would have been if it weren't for Dr. Marcus. Dr. Marcus truly is a Great doctor! Professionalism, Knowledge, Confidence, Compassion, Understanding, Honesty, Empathy, Commitment and Humanity. Thank you Dr. Marcus for who you are . . . . keeping we, your patients healthy. read more

Dr. Marcus is the most inquistive, kind never give up doctor i have ever met. Dr. Marcus truly wants to help you find the answers you have been searching for. His never give up attitude makes him extremely value to his patients. I personally believe he is the dr most people dream of working with but are unable to find. He has been an expert with me and my thyroid issues. I would highly recomend Dr. Marcus. His willingness to help and to solve your medical issues is unsurpassed. read more

I've been going to Dr. Marcus since 1991. I wish every doctor was as caring as he is. He is never rushed and spends a lot of time answering questions and explaining what he is doing. Unlike other friends that have thyroid problems and never seem to be on the right dose of medication, I have always felt fantastic under Dr. Marcus' care. I no longer live in Orange County and my insurance doesn't cover my annual visits to see Dr. Marcus, but I still make the drive to see him. read more

I have been a patient of Dr. Marcus' for over 30 years. Like many of his patients he has offered treatment to symptoms and diseases which other clinicians found too complex or ignored. I work in health care and interact with many colleagues and couldn't recommend Dr. Marcus any more. He sees every member of my family and will continue so long as he is in practice. read more

After being sick for many years and sent to various other specialists (ear, nose and throat, gastroenterologist,hematologist, etc) without any success, a close friend referred me to Dr. Marcus. He is a true professional endocrinologist that runs very detailed patient clinical reviews prior to ordering various lab work tests. He confirms his diagnosis by further bloodwork, other tests, etc. Dr. Marcus is very thorough. He answers any and all questions you may have regarding your illness and teaches his patients how to manage their AutoImmune Diseases. He is up to date on new studies, medications and updated treatments. Choosing Dr. Marcus, was one of the best decisions I have made in my life. I would recommend Dr. Marcus- an excellent, researcher, doctor and endocrinologist. Dr. Marcus cares about his patients and is one of the best doctors I have had the pleasure of knowing. read more

Dr. Marcus is the best Endocrinologist! I highly recommend him! I've been a patient of his since 2011. He has changed my life for the better! Almost my entire family sees him now with incredible results! read more

Please do yourself a favor and choose another doctor that will give you the respect you deserve. There are many to choose from in Southern California. He just wants to do experiments on you that ll leave you worse than when you came to see him . Horrible doctor and horrible experience . read more

Since age 12, I've felt sick nearly every day. By age 16, I was planning my life around my limitations. Despite my suspicions, my family doctor wouldn't give me a blood test due to my weight-- "too thin to have hypothyroidism". My symptoms were chalked up to 'growing up', but none of it made much sense. After years of managing my symptoms on my own, my dad suggested that I see Dr. Marcus (whom he also sees for his diabetes) to get blood work done and I'm so glad I did-- his knowledge is immediately apparent and he makes me an active participant in the process rather than sending me on my way with some meds and little explanation. Such comprehensive care has given me a new life and that's no exaggeration! I'm finally able to major in the subject I've always loved but didn't have the energy to pursue. I can actually take walks and enjoy life's most simple pleasure, FOOD, without feeling nauseous!! 'Good doctor' is an understatement and my case isn't unique-- this guy probably gives people their lives back on a regular basis read more