Practice

Clinical focus, refined over 25 years.

With more than 25 years in naturopathic medicine, I specialize in naturopathic oncology and gastrointestinal health, and work with patients across a range of complex illness — from mold and Lyme to autoimmunity, long-COVID, and vaccine-related illness. My approach is a relaxed, ongoing conversation as we uncover the factors contributing to your symptoms.

Dried herbs, glass apothecary bottles, and a mortar and pestle in soft window light
01

Naturopathic Oncology

Over 15 years focused specifically on naturopathic oncology. I work with patients across all cancer types and stages — including those undergoing conventional therapies, where my role is to optimize intended effects while mitigating side effects. For patients not using conventional therapies, I develop aggressive, individualized prevention and treatment programs.

02

Gastrointestinal Health & Sulfur Research

More than a decade of research into sulfur and hydrogen sulfide metabolism informs my approach to SIBO, IBS, and inflammatory bowel diseases, as well as chronic skin conditions and other symptoms tied to sulfur-related dysfunction.

03

Autonomic Nervous System Regulation

ANS dysregulation is a central and commonly-overlooked factor in chronic illness and the failure to respond to treatment. Over several years I have incorporated a growing number of tools into my practice to help patients achieve greater ANS balance and flexibility. This allows all other therapies a greater potential to be beneficial.

04

Complex Chronic Illness

Deep experience with mold-related illness, Lyme disease, chronic fatigue, fibromyalgia, and a wide array of autoimmune and complex conditions that have remained unresolved elsewhere.

05

Long-COVID & Vaccine-Related Illness

In recent years a growing share of the practice has focused on long-COVID and vaccine-related illness — often overlapping with mold, mast-cell activation, and dysautonomia patterns that require a patient, layered treatment approach.

06

Personalized, Research-Driven Care

Every patient is a unique puzzle. I dive into the current research to build tailored treatment programs that address each individual's specific metabolic, immune, and lifestyle context — not a template.

In patients' own words

What patients say.

A selection of five-star Google reviews from people who have worked with Dr. Nigh — many over the course of years or decades.

  • "I am incredibly grateful for the care and support I received from Dr. Greg Nigh during my cancer journey. He was exceptionally attentive — not only to my needs, but also to the concerns of my family — and always took the time to listen and truly understand what we were going through. The treatments and routines he recommended were extremely beneficial throughout my chemotherapy and radiation. In fact, my primary oncologist was amazed at how well I handled the therapies and how strong I remained during treatment. I am absolutely confident that Dr. Nigh's guidance played a major role in that. I would highly recommend Dr. Greg Nigh to anyone seeking compassionate, thoughtful, and effective naturopathic care."

    Ron W.

  • "Greg, as he wants to be called, has saved my husband's life. My husband Larry had radiation for prostate cancer many years ago, and it came roaring back as 4th-stage metastatic bone cancer 8 years ago. About 4 years ago he started working with Greg, who has treated him with gentle, welcoming kindness and genuine interest — a major healing modality all on its own. Greg has committed himself to ongoing research, giving him new information to apply to unique, tailor-made treatment plans, and he can pivot on a dime as needed. Today Larry's PSA is below 1%. All of his multiple labs are in the green. Amazing grace. Thank you, Greg."

    Christine B.

  • "Open-minded, innovative, and a true partner in health is Dr. Nigh. He goes the extra 5 miles. He is really engaged in research, and remains CURIOUS, which is such an important quality in a human being, let alone a health care practitioner."

    Diana C.

  • "I've been working with Dr. Nigh for almost 10 years now, and often refer his practice to anyone struggling with a cancer or Lyme diagnosis. Dr. Nigh is by far the most caring doctor I have ever experienced — taking the time to thoroughly listen, making the best suggestions, but never pushing treatments I was uncomfortable with or that were unattainable due to cost. He is truly worth every penny of out-of-pocket cost, and he will work a plan that is doable both financially and mentally. I'm so grateful for his help reaching remission initially and now helping me fight actively once again. Schedule a consult — you won't be disappointed!"

    Abigail & Jonathan D.

  • "Dr. Nigh has been my naturopathic doctor for years, initially in a clinical setting, now online. We worked together to save me from cancer destruction. His guidance and innovative protocols were invaluable and remain successful. His years of expertise, and how I learned to use the important remedies he suggested, keeps me marching along years later. A highly knowledgeable health professional, published researcher, and stellar human. God bless you, Greg!"

    Jeanette S.

  • "Several years ago during my SIBO protocol I had some questions for Dr. Nigh. He answered them quickly and it greatly allowed me to continue the healing journey. His assistant was also a valuable aid in addressing some additional food choices I needed to consider. Extremely grateful for their generous and knowledgeable help."

    A. V.

  • "I have gotten good advice from Dr. Nigh. I had an unexpected diagnosis earlier this year and he has helped me understand things and offer guidance to help me have the confidence I need to know I am going to be ok. To me, that's what a doctor should really do!"

    J. J.

  • "Dr. Greg's explanations are clear and thoughtful. In addition, he is calm and keeps me calm so I don't panic — no pressure on his part."

    Mary C.

  • "Well how about a review from a totally "unbiased" long-time customer — his aging 85-year-old father. Because of my obvious bias you can take my comments with a grain of salt. But let me share our outcomes after 25 years of following Greg's health-maintenance and illness-avoiding recommendations. My wife Barb, at 83, still does her 4-mile run every other day. Fifteen years ago she had breast cancer, successfully treated via Greg's recommendation of Brachy-Therapy radiation without the follow-up chemotherapy. My own father died at 52 from his first heart attack; his father died at 48. I'm 85 and still walking 3.5 miles three days a week plus weights on the off days. I can call Greg anytime with a new ache or pain and he is right on it with a currently researched remedy. If Greg takes care of his patients anything like how he takes care of his parents, they can rest assured they are in good hands."

    Cal N.

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