IVC and the Riordan Approach to Adjunctive Cancer Care: 7 Key Questions

By The Riordan Clinic Provider Team

IVC and the Riordan Approach to Adjunctive Cancer Care: 7 Key Questions has been reviewed and updated from the original Health Hunters article Vol. 31 No. 10 in October 2017.

Q1. What is IVC and how does it benefit cancer patients?

Intravenous Vitamin C, also referred to as IVC, is an adjunctive cancer therapy widely used in naturopathic and integrative oncology settings. Two decades of ground-breaking research on IVC therapy at the Riordan Clinic have resulted in the Riordan IVC Protocol for Adjunctive Cancer Care.

While the focus of this protocol is IVC, Dr. Hugh Riordan emphasized the importance of providing comprehensive wellness care for the cancer patient in conjunction with IVC therapy.

Q2. What are the proven benefits of IVC therapy in the care of cancer patients?

During this intravenous treatment, high doses of buffered ascorbic acid enter your body through a small tube inserted into a vein in your arm or through a port. This results in blood levels of vitamin C that reach 300-400 times the levels achievable by oral intake alone. The cancer patient can benefit from IVC therapy in several ways:

  1. Because cancer patients are often depleted in vitamin C, the IVC provides a rapid means of restoring tissue reserves.1
  2. IVC improves the quality of life in cancer patients by a variety of metrics, as documented in published studies.1
  3. IVC reduces inflammation as measured by C-reactive protein levels.1
  4. IVC is preferentially toxic to tumor cells but not to normal cells.1
  5. IVC inhibits the growth factor that promotes new blood vessels to grow towards the tumor.1
  6. IVC reduces the production of pro-inflammatory cytokines, which down-regulates the “micro-inflammatory cellular environment” of cancer cells.2

Q3. Is IVC a vitamin or a drug?

IVC shifts ascorbate from a simple anti-scurvy vitamin to a surprisingly beneficial pro-oxidant with powerful pharmaceutical actions. Pharmaceutical IVC doses have shown significant anticancer effects in animal models and tissue culture studies.3 This well-studied effect has been described as the selective cytotoxicity effect of high dose ascorbate on tumor cells.4 Numerous research institutions have replicated this effect over the last several decades. However, only recently has research on sepsis brought this effect to the attention of conventional medicine.

Q4. Is IVC “a natural chemotherapy agent?”

Although the literature and clinical studies suggest that IVC has a good safety profile and important anti-tumor activity,5 it is nevertheless not considered a “stand-alone” chemotherapy agent. Instead, IVC is best utilized as one component of a multi-faceted, adjunctive care approach that would best include dietary, nutritional, and lifestyle changes that support overall wellness in the cancer patient. When used in this wellness context, IVC acts as an ideal adjunctive therapy that can:

  1. Reduce chemotherapy side effects6
  2. Improve survival time6
  3. Enhance the quality of life6 for the cancer patients receiving it once or twice weekly as part of an overall lifestyle program of care

Q5. How is IVC used in conjunction with traditional oncology?

Published studies have shown that IVC therapy can be used in parallel with traditional cancer treatments, such as surgery and chemotherapy, without interfering with their effectiveness.6 Most, but not all, patients choose to enlist a standard of care team including their oncologist and an integrative oncology team to provide the best of both modalities for superior outcomes.

Q6. What are the “basics” of the Riordan IVC Protocol?

The Riordan IVC Protocol for Adjunctive Cancer Care is an integrative program that favors optimal treatment for both the cancer disease and the wellness care of the patient who has a cancer diagnosis. 

The decision to start IVC is made by Riordan Medical Providers after careful review of the patient’s medical history, in conjunction with comprehensive lab testing. Treatment is to be continuous with infusions of IVC two times per week, on average. Regular treatments with IVC, without lapses in treatment, have been shown by our studies to increase the overall effectiveness of the IVC in the suppression of tumor growth.

The Multi-C Oral Vitamin C Protocol is advised 2-3 times daily, especially on non-IVC days, as an important but often neglected part of the effective implementation of the Riordan Protocol. The Multi-C Protocol includes oral liposomal C, sodium ascorbate, and ascorbyl palmitate to maintain high serum, extracellular, and intracellular levels of vitamin C between intravenous infusions.

Infusion time and financial requirements need to be carefully assessed prior to beginning IVC treatment to determine whether the patient can sustain the benefits of the complete protocol. IVC is typically continued until there is an improvement of patient conditions (stabilization of patient tumor or no detection of cancer for a 12-month period of time). At such a point, treatment frequency is gradually tapered while maintaining the Multi-C Oral Protocol.

Therapeutic IVC Dosage Testing

  • High doses of intravenous Vitamin C are titrated up to a therapeutic dose as outlined in the Riordan IVC Protocol, which is now a standard of integrative cancer care worldwide.
  • Starting with a low, safe dose of 15 grams, the patient’s resulting blood level is assessed to find out what level of blood saturation is achieved at this dose.
  • This starting dose is escalated each subsequent day (25 grams, 50 grams, 75 grams, and occasionally 100 grams in very heavy patients) until a target dose of near 400 mg/dl is achieved.
  • Riordan uses two methods to assess post-IVC saturation levels: 
    • Serum ascorbate testing at the Bio-Center Laboratory
    • Fingerstick testing using a glucometer (if serum testing is not readily available.* Note: the Vitamin C molecule is similar in shape and structure to the glucose molecule, and studies have utilized glucometer readings to correlate with the therapeutic levels of IVC in the bloodstream.
  • Each patient’s unique blood findings are used to determine their therapeutic IVC dose.

Q7. What are the “adjunctive” components of the Riordan IVC Protocol for Adjunctive Cancer Care?

Following Dr. Hugh Riordan’s death in 2005, the Riordan approach to the care of cancer patients was formulated by way of 7 key verbs in 7 precepts:

  1. Create Co-learner Relationships

Cancer patients co-learn best in partnership with their Riordan Clinic Doctors and medical team.

  1. Identify the Causes

The Real Health Discovery Laboratory Profile is utilized to search for and address 17 common underlying causes that perpetuate conditions that have been shown to give rise to cancer. Correcting these factors can help the body’s healing system slow and possibly eliminate cancer growth.

  1. Characterize Biochemical Individuality

The Real Health Discovery Laboratory Profile analyzes vitamins, minerals, amino acids, fatty acids, hormones, food reactions, inflammation markers, and additional biochemical indicators which can serve as:

    • A baseline of your current health status
    • An inventory of correctable health factors
    • A source of valuable clues that point to correctable carcinogenic factors
  1. Care for the Whole Person

Cancer is a disease that occurs in the real life of a human being. The complex life histories, traumas, stressors, toxic exposures, dietary indiscretions, medication side effects, spiritual crises, poor lifestyle habits, sleep disorders, physical, emotional, psychological, financial, marital and many other health challenges – all of these may be playing into the grueling challenges of a cancer care plan.

The Riordan Approach is not a simple solution for this complex array of lifestyle issues.  It is an acknowledgment that an adjunctive cancer care assessment is more than just infusing vitamin C into the vein of that human being.

  1. Choose Food as Medicine

Although there is no single diet that is widely acknowledged as effective in cancer patient care, the importance of making healthy food choices is paramount for good cancer outcomes.

Food issues that need to be addressed include food wholeness, safety, quality, hidden inflammatory lectins, mold toxins, GMO issues, and effects of food on the gut biome, phytonutrient factors, glycemic issues, ketogenic programs, and the appropriateness of other controversial cancer diet plans.

  1. Cultivate Healthy Reserves

The Riordan Approach, like gardening, takes time and is the result of continuous effort and ongoing co-learning. Healthy reserves include nutrients, habits, social networks, spiritual resources, and a strong self-concept.

The Real Health Discovery Laboratory Profile is a valuable key and starting point for identifying deficiency states that can be corrected as an integral part of building whole-life reserves.

  1. Discover the Healing Power of Nature

An old Latin proverb says: “Medicus curat, natura sanat,” which means the doctor cares [for the patient], nature heals [the patient]. The Riordan Approach integrates the ancient wisdom of natural healing techniques with modern medical science.





  1. Mikirova, N., Casciari, J., Riordan, N. et al. Clinical experience with intravenous administration of ascorbic acid: achievable levels in blood for different states of inflammation and disease in cancer patients. J Transl Med 11, 191 (2013). https://doi.org/10.1186/1479-5876-11-191
  2. Tarhini, A. A., Lin, Y., Zahoor, H., Shuai, Y., Butterfield, L. H., Ringquist, S., Gogas, H., Sander, C., Lee, S., Agarwala, S. S., & Kirwood, J. M. (2015). Pro-Inflammatory Cytokines Predict Relapse-Free Survival after One Month of Interferon-α but Not Observation in Intermediate Risk Melanoma Patients. PloS one, 10(7), e0132745. https://doi.org/10.1371/journal.pone.0132745
  3. Stephenson, Chris. Midwestern Regional Medical Center. (2006, August – 2010, July). Study of High-Dose Intravenous (IV) Vitamin C Treatment in Patients With Solid Tumors. Identifier NCT00441207. https://www.clinicaltrials.gov/ct2/show/study/NCT00441207
  4. Vissers, M., & Das, A. B. (2018). Potential Mechanisms of Action for Vitamin C in Cancer: Reviewing the Evidence. Frontiers in physiology, 9, 809. https://doi.org/10.3389/fphys.2018.00809
  5. Fritz, H., Flower, G., Weeks, L., Cooley, K., Callachan, M., McGowan, J., Skidmore, B., Kirchner, L., & Seely, D. (2014). Intravenous Vitamin C and Cancer: A Systematic Review. Integrative Cancer Therapies, 280–300. https://doi.org/10.1177/1534735414534463
  6. Böttger, F., Vallés-Martí, A., Cahn, L. et al. High-dose intravenous vitamin C, a promising multi-targeting agent in the treatment of cancer. J Exp Clin Cancer Res 40, 343 (2021). https://doi.org/10.1186/s13046-021-02134-y
  7. Saul, A. W. (Ed.). (2014). Orthomolecular Treatment of Chronic Disease: 65 Experts on Therapeutic and Preventive Nutrition. Basic Health Publications, Inc.