Office in Roslyn Heights
  • Areas of Practice:
  • Internal Medicine

Dr. Roger G. Mazlen

About Roger G. Mazlen, MD

Dr. Roger Mazlen is head of Mazlen Medical Arts, PC and an internationally recognized physician specializing in internal medicine with over 30 years experience in private practice and cutting edge medical research.

Dr. Mazlen is an expert in the diagnosis and treatment of CFIDS, viral and bacterial infections, immune dysfunction, Fibromyalgia and cancer-related malnutrition and fatigue.

A fellow of the American College of Nutrition, an attending at Long Island Jewish Hospital Center, Dr. Mazlen has seen over a thousand cases of CFIDS and CFIDS-like disorders, the majority of which attained significant improvement under his treatment and care.

Dr. Mazlen also has significant clinical experience in managing fibromyalgia, Lyme disease, heavy metal toxicity, sleep disorders and cancer-related fatigue and malnutrition. He has successfully organized a major international medical meeting at the MD Anderson Hospital on Cancer and Nutrition. He is also a presenter at the annual SASS Medical Research Foundation Seminar and serves as one of their expert lecturers on nutrition and breast cancer.

Using cutting-edge treatments, including immune boosting, herbal and hormone therapies, Dr. Mazlen continues to put patients from around the world back on the road to health and vitality.

Dr. Mazlen also qualified and served as a medical expert witness in the areas of chronic fatigue syndrome and heavy metal toxicity.

Doctor Info

Hospital Affiliations

  • Medical attending at Long Island Jewish Hospital
  • Previously served as senior medical attending in the Division of Endocrinology, Diabetes and Metabolic Bone Disease of the Mount Sinai Medical School
  • Adjunct medical staff at Northwell

Professional Memberships

  • Fellow of the American College of Nutrition

Honors & Awards

  • NY Top Docs (2017 – Present)
  • Who’s Who Lifetime Achievement (2017)
  • Patients Choice Award (2010-2011)
  • Recipient of a lifetime achievement award (2020)
  • Comprehensive History & Physical
  • Testing Procedures (including laboratory testing–see Testing Procedures tab under Resources for Dr. Mazlen’s comprehensive list)
  • Aperiomics Laboratory Testing Available
  • Electrocardiograms
  • Pulmonary Function Testing
  • Holter Monitoring
  • Select Ultrasonography
  • Intradermal Testing
  • Infectious Disease Panels
  • Vaccinations (influenza, Pneumoccal Pneumonia)
  • Medical Nutrition Counseling
  • Telephone Consultations
  • Medical Nutrition Counseling and Cancer Support
Our Office
Phone: (516) 869-0717
Fax: (516) 869-0718
Monday: 9:00 AM - 5:00 PM
Tuesday: 9:00 AM - 5:00 PM
Wednesday: 9:00 AM - 5:00 PM
Thursday: 9:00 AM - 5:00 PM
Friday: 9:00 AM - 5:00 PM
Saturday: Closed
Sunday: Closed

“Currently I am a patient of Dr. Roger Mazlen. In 2017, I was diagnosed with chronic fatigue and left without help. Living in upstate New York and spending two years looking for answers to no avail, I found my savior, Dr. Mazlen. After visiting this practice in person July 2019, I was then placed on supplements. At first I wasn’t a believer in supplements, and I sure am now. After starting them in August 2019, I started hiking again. I had to take considerable time off as I wasn’t well enough to hike in 2017/2018. My goal was to become an Adirondack 46r! This means you must climb all 46 Adirondack High Peaks which are all over 4,000 ft!!! I was able to complete 5 in the fall of 2019, 23 in 2020, and 5 in 2021. I started this journey in 2012 and on June 23, 2021, I became and Adirondack 46r! There is no way that I could have hiked any of these high peaks without the help of Dr. Mazlen. He absolutely changed my life, and he can change yours.”



“And, I will forever be grateful that I had the good fortune to walk into your office and into a Lyme diagnosis that so many Lyme sufferers have had to search long and hard for.”



“Dr. Mazlen, thank you so much for your time & guidance. As I told you at our first visit, I had plugged along for years going from specialist to specialist …returning to my GP to just have him throw his hands up in the air …My naturopath had brought me as far as she could, feeling that dealing with the viruses living & colonizing in my body was the next step; but she could not help me here as she did not have the schooling to prescribe antivirals. YOU WERE THE NEXT STEP! And I’m so glad that I researched & found you. You have definitely taken me to the next level…Thank you again for your care & for helping me to be at my best health while living with and managing ME/CFS. You are a gift from Almighty God.”



“Thank you for all your knowledge and support; since my first apointment in September, I have been more hopeful that I will return to good health. We are lucky to have found you.”