Metformin, a prescription drug used to manage diabetes, has shown some benefits in lower risks of cancer and better survival, mostly among people with diabetes or high blood sugar.

How do experts use metformin?

Integrative experts provide recommendations for metformin in treating people with cancer. Learn more about the approaches and meanings of recommendations.

Clinical practice guidelines

Metformin is not mentioned for treating cancer in any of the clinical practice guidelines that we consulted.

Published protocols, programs, and approaches

Metformin is used in programs, approaches, and protocolsa package of therapies combining and preferably integrating various therapies and practices into a cohesive design for care from these integrative oncologists, drawing from both scientific research and observations from years or even decades of treating people with cancer.

We do not recommend specific integrative protocols or programs but provide information for you to evaluate with your healthcare team.

Keith Block, MD

Block KI. Life over Cancer: The Block Center Program for Integrative Cancer Care. New York: Bantam Dell. 2009.

The integrative Block Program has recommendations to people who are at different places along the cancer continuum:

  • Those who’ve been recently diagnosed
  • Those in treatment
  • Those who’ve concluded treatment and need to remain vigilant to prevent recurrence

Uses of metformin:

  • Pharmaceutical glycemia terrain modifier
  • If you are taking glycemic support supplements or terrain modifiers and they are not correcting your glycemic imbalance, Keith Block, MD, suggests talking with your physician about increasing the doses of these, and/or considering using metformin. “Metformin . . . is approved for insulin resistance, reduces the liver’s ability to release glucose and so may be helpful for patients whose glucose imbalance results from this mechanism.”

Raymond Chang, MD, FACP

Chang R. Beyond the Magic Bullet: The Anti-Cancer Cocktail. New York: Square One Publishers. 2012.

This book describes a “new therapy based on the knowledge that certain off-label drugs, nutrients, and therapies are each somewhat effective against cancer.” Dr. Chang combines approaches for added benefit.

Neil McKinney, BSc, ND

McKinney N. Naturopathic Oncology, Fourth Edition. Victoria, BC, Canada: Liaison Press. 2020.

This book includes descriptions and uses of many natural and complementary protocols for cancer in general and for specific cancers. It also includes information on integrative support during conventional cancer treatment.

Uses of metformin:

  • Breast cancer
  • Carcinoid/neuroendocrine cancer
  • Lymphoma
  • Melanoma
  • Pancreatic cancer
  • Prostate cancer
  • Sarcoma
  • Thyroid cancer

Expert commentary

Integrative physician and CancerChoices advisor Barry Elson, MD, February 18, 2021: Observationala type of study in which individuals are observed or certain outcomes are measured, but no attempt is made to affect the outcome (for example, no treatment is given); an example is a study that records people’s diets, but doesn’t try to alter their diets, and looks for patterns of disease or other outcomes related to different foods studies find benefit in those with insulin resistance and/or obesity, perhaps because metformin stimulates the tumor suppressor AMPK. AMPK is poorly activated in obese patients, since they are generally deficient in adiponectin, an AMPK-activating hormone.

In addition to chemical stimulation of AMPK, avoiding sugar and taking other measures to curb insulin resistance can achieve some of the same impacts without the side effects of metformin. Several excellent natural remedies are available, such as these:

  • Chromium 
  • Alpha lipoic acid
  • Berberine 
  • Fish oil
  • Cinnamon

CancerChoices staff: We strongly recommend that you use metformin only as directed by your licensed physician.

Resource

Keep reading about metformin

Authors

Nancy Hepp, MS

Lead Researcher and Program Manager
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Ms. Hepp is a researcher and communicator who has been writing and editing educational content on varied health topics for more than 20 years. She serves as lead researcher, program manager, and writer for CancerChoices. Her graduate work in research and cognitive psychology, her master’s degree in instructional design, and her certificate in web design have all guided her in writing and presenting information for a wide variety of audiences and uses. Nancy’s service as faculty development coordinator in the Department of Family Medicine at Wright State University also provided experience in medical research, plus insights into medical education and medical care from the professional’s perspective.

Nancy Hepp, MS Lead Researcher and Program Manager

Andrew Jackson, ND

Research Associate
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Andrew Jackson, ND, serves as a CancerChoices research associate. As a naturopathic physician practicing in Kirkland, Washington, he teaches critical evaluation of the medical literture at Bastyr University in Kenmore, Washington. His great appreciation of scientific inquiry and the scientific process has led him to view research with a critical eye.

Andrew Jackson, ND Research Associate

Reviewers

Laura Pole, RN, MSN, OCNS

Senior Clinical Consultant
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Laura Pole is senior clinical consultant for CancerChoices. Laura is an oncology clinical nurse specialist who has been providing integrative oncology clinical care, navigation, consultation, and education services for over 40 years. She is the co-creator and co-coordinator of the Integrative Oncology Navigation Training at Smith Center for Healing and the Arts in Washington, DC. Laura also manages the “Media Watch Cancer News That You Can Use” listserv for Smith Center/Commonweal. In her role as a palliative care educator and consultant, Laura has served as statewide Respecting Choices Faculty for the Virginia POST (Physician Orders for Scope of Treatment) Collaborative as well as provided statewide professional education on palliative and end-of-life care for the Virginia Association for Hospices and Palliative Care.

For CancerChoices, Laura curates content and research, networks with clinical and organizational partners, brings awareness and education of integrative oncology at professional and patient conferences and programs, and translates research into information relevant to the patient experience as well as clinical practice.

Laura sees her work with CancerChoices as a perfect alignment of all her passions, knowledge and skills in integrative oncology care. She is honored to serve you.

Laura Pole, RN, MSN, OCNS Senior Clinical Consultant

Dr. Fuller-Shavel is a GMC-registered integrative medicine doctor with degrees in medicine and natural sciences from the University of Cambridge. Dr. Fuller-Shavel is a fellow of the College of Medicine and the vice chair for BSIO (British Society for Integrative Oncology). Alongside her science and medical training, Dr. Fuller-Shavel holds multiple qualifications in nutrition, integrative medicine, health coaching, herbal medicine, yoga, mindfulness and other mind-body approaches.

Dr. Fuller-Shavel is the director of Synthesis Clinic, an award-winning multidisciplinary integrative medicine practice in Hampshire, UK, specializing in women’s health, gut health (microbiome and gut-brain axis) and mental health. She combines her clinical work in women’s health and supporting patients with breast and gynecological cancer with education and training for healthcare professionals and research in precision cancer medicine and precision nutrition.

Nina Fuller-Shavel, MB, BChir, MA Hons, FBANT, IFMCP, DipIM, PG Cert RYT300

Last update: May 9, 2023

Last full literature review: March 2022

CancerChoices provides information about integrativein cancer care, a patient-centered approach combining the best of conventional care, self care, and evidence-informed complementary care in an integrated plan cancer care. We review complementaryin cancer care, complementary care involves the use of therapies intended to enhance or add to standard conventional treatments; examples include supplements, mind-body approaches such as yoga or psychosocialtherapy, and acupuncture therapies and self carelifestyle actions and behaviors that may impact cancer outcomes; examples include eating health-promoting foods, limiting alcohol, increasing physical activity, and managing stress practices to help patients and professionals explore and integrate the best combination of conventionalthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy and complementary therapies and practices for each person.

Our staff have no financial conflicts of interest to declare. We receive no funds from any manufacturers or retailers gaining financial profit by promoting or discouraging therapies mentioned on this site.