Modified citrus pectin is a plant-based dietary supplement with very preliminary evidence of anticancer and antimetastatic effects.

Safety and precautions

Side effects or adverse events

MCP is generally safe, with few severe (higher than grade 2) therapy-related adverse events. The most common side effects in studies have been itching (pruritus), indigestion (dyspepsia), and flatulence.1Azémar M, Hildenbrand B, Haering B, Heim ME, Unger C. Clinical benefit in patients with advanced solid tumors treated with modified citrus pectin: a prospective pilot study. Clinical Medicine: Oncology. 2007;1:S285.

Interactions with medications

Pectin can interfere with the body’s ability to absorb some drugs, such as these:2McMillen M. Pectin. Web MD. September 24, 2021. Viewed April 6, 2023.

  • Digoxin
  • Lovastatin
  • Tetracycline antibiotics

Do not use (contraindications)

People who are allergic to citrus fruits should avoid MCP.3McMillen M. Pectin. Web MD. September 24, 2021. Viewed April 6, 2023.

Keep reading about modified citrus pectin


Nancy Hepp, MS

Lead Researcher
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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 and writer for CancerChoices and also served as the first program manager. 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


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

Last update: December 18, 2023

Last full literature review: April 2023

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.

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