Why You Should Stay Away from Insulin Potentiation Therapy

Robert Baratz, M.D., D.D.S., Ph.D.
August 31, 2013

Insulin potentiation therapy (IPT) is one of several unproven, dangerous treatments that is promoted by a small group of practitioners without trustworthy evidence that it works. It is claimed to be effective against cancer, infectious diseases, arthritis, and many other conditions. Several patents have been issued, but patents are based on whether or not something appears to be original. Proof of effectiveness is not required.

Background History

IPT is based on the notion that intravenous insulin increases the effect of medications so that lower doses can be used. Its promoters suggest that somehow the insulin “opens the pores” of cells throughout the body so that certain drugs enter more easily. It is used mainly for treating cancer. The leading proponent is Stephen B. Ayre, M.D., of Burr Ridge, Illinois, who coined the treatment’s name in 1986 [1]. In 2003, his Web site stated:

The treatment . . . features an innovative low-dose chemotherapy protocol called Insulin Potentiation Therapy (IPT) that uses 75-90% less chemotherapy than the traditional treatment to destroy cancer cells. This low dose treatment causes little to none of the negative side effects such as loss of appetite, nausea, hair loss and fatigue.

IPT was developed in Mexico City in 1932 by Dr. Donato Perez Garcia, Sr. and was used by him for decades to treat a wide variety of cancers, including cancers of the breast, lung and prostate. His son, Donato Perez Garcia Bellon, M.D., and his grandson, Donato Perez Garcia, Jr., M.D, followed Dr. Garcia in this work. Collaborating with these two physicians over the last 25 years, Dr. Ayre studied and researched IPT, resulting in their publication of scientific articles on the therapy in medical journals.

Cancer cells have 20 times more insulin sensitive receptors than normal healthy cells. By introducing insulin into the body before the chemotherapy drugs, the insulin highlights the cancer cells due to their higher insulin receptor content, and selectively enhances their absorption of the chemotherapy. Less chemotherapy is needed to kill the cancer cells, with less dose related side effects. Glucose is given to counter insulin’s other effect of lowering blood sugar [2].

IPT is performed by injecting insulin into the patient’s vein. After the blood sugar falls, the practitioners rapidly inject chemotherapy drugs in doses that are below the amounts that have been proven effective. Immediately thereafter, a strong sugar solution is injected to arouse the patient. In some cases, several chemotherapy agents are mixed together even though one or more may not have been validated in full doses for the patient’s tumor. This procedure is typically performed in medical offices where resuscitation equipment and training are minimal to nonexistent. The practitioners who perform this are “trained” in two-day courses and “licensed” to perform IPT. In 2003, about 100 were listed in the directory on IPTO.org and one practitioner’s Web site quoted a cost of $15,500 to 17,500 for 3 to 4 weeks of “intensive” IPT therapy plus $2,000 to $3,000 per week additional for up to 4 weeks of “home maintenance” therapy.” [3] About half of the 69 listed doctors who practiced in the United States also offered chelation therapy, which is equally disreputable.

Proponents claims that IPT is free of side effects, However, a rapidly falling blood sugar level can produce coma, shock, stroke, and even death, and I also know of at least one case where the patient got side effects from the chemotherapy. In 2003, Ayre’s Web site further stated:

Steven G. Ayre, M.D., has spent twenty-seven years single-handedly researching, publishing, and speaking at meetings on the science of Insulin Potentiation Therapy. He began practicing IPT in the United States in 1997, after he had become convinced, due to his lengthy study, that this therapy was a much improved way of using chemotherapy. In September of 2000, Dr. Ayre and his colleagues made a presentation before the Cancer Advisory Panel of the National Center for Cancer Complementary and Alternative Medicine at the National Institutes of Health in Bethesda, Maryland. This meeting has led to a collaborative effort with cancer researchers at the Comprehensive Cancer Center at the University of Wisconsin, Madison, to design and perform clinical trials on IPT. The funding is provided by the National Cancer Institute. Because of the perceived patient need, and because all drugs used in the therapy are already FDA approved, IPT treatments are now being made available to persons here in the USA. Good patient reimbursement by health insurers is the rule [4].

This statement is very misleading. Ayre’s “researching” and “lengthy study” did not include any appropriate study to test whether IPT worked. Nor has the clinical trial to which the passage refers been carried out. To maintain FDA approval for a clinical study it is necessary to have approval from an Institutional Review Board. The “review board” that approved the study was composed of dubious practitioners (most of whom promote chelation therapy) and was ordered to shut down in January 2001 after the FDA concluded that it was run improperly. In retrospect, it appears to me that the board and the proposed study were part of an scheme to make patients think they were part of a legitimate study. It is also curious that the study is still mentioned on Ayer’s Web site even though it was canceled more than a year ago. Ayre did attend a meeting of an NIH advisory panel at which possible preliminary investigation was discussed [5]. However, there has been no visible evidence that the suggested data collection has taken place. As far as insurance coverage is concerned, I do not believe that insurance companies knowingly pay for IPT therapy. One IPT provider’s Web site states that “some insurance companies . . . will cover IPT treatments the same way they would cover standard chemotherapy.” However, coding IPT as standard chemotherapy on a claim form would constitute insurance fraud. BlueCross of California classifies IPT as “investigational/not medically necessary” and does not cover it [6].

IPT is often described as an “off label” use of insulin, with a claim that this is “allowed.” This description is not quite accurate. The FDA only regulates the sale of products that cross state lines, and approves labeling of drug products for particular uses. Violation of those uses can result in seizure of products and stoppage of further sales. However, under some circumstances a physician can take a drug licensed for one use and use it for another or may use dosages higher than those on the label. This concept is not a wide open door to illicit use; nor can it be used to justify unapprroved “research” that lacks a rational basis. Licensed physicians are expected to conform to a standard of care and do what is clinically acceptable and safe. IPT does not fit this description. No major medical school, hospital, or other institution has embarked on a clinical trial, largely because the “therapy” is dangerous, potentially lethal if too much insulin is administered, and does not a have a sound biological basis.

Lack of Evidence

IPT’s promoters use vague and misleading language to make it seem legitimate. It is not. When examined even casually, the claimed “cures” are bogus. Besides the danger of insulin shock and death, using the wrong chemotherapeutic agent(s) or doses that are too low can foster the development of resistant cancer cell strains. Thus, IPT can prevent appropriate chemotherapy from working later and make an otherwise curable cancer incurable.

Ayre’s home page states that, “while individual anecdotal case reports over forty years suggest that this treatment may be effective, there is at present no collection of scientific data to validate insulin potentiation iherapy as a treatment for malignant neoplastic diseases, or cancer.”

The IPT.org Web site is operated by Chris Duffield, Ph.D., a man who says he became “entranced by the IPT story” Dr,. Ayre told him and helped form a company that tried unsuccessfully to attract investors to fund IPT research [7]. Duffield discusses 19 “mechanisms proposed for how IPT works,” but he notes that “no one knows really for sure” whether the explanations are valid [8]. He also states:

Many doctors and patients are looking for statistics, and we simply have to tell people that we do not have them. If they insist on having statistics, IPT is not yet for them. However, a lot of people have heard about IPT from friends, or have talked with doctors who have had excellent results with IPT. For some people, the IPT concept makes sense, and the reported benefits are so attractive, that they decide to give it a try.

Here is the closest thing we have to statistics. It is an estimate from Dr. Donato Perez Garcia 3, based on his many years of IPT experience, and from experienced passed down from his father. While stated as facts, these are just his personal opinions, and are not agreed on by all other IPT doctors. This text is from an email he sent to a patient on June 6, 2002. . . .

The email describes “response rates for a full remission” of 25% to 95% for various situations [9], but it provides no details that would enable independent assessment of the claims.

In 2003, a scientific journal reported that women with breast cancer received methotrexate plus insulin did better than women treated with methotrexate alone [10]. Although the report suggests that insulin may have a short-term effect, it did not any data on long-term effects or health outcomes. Moreover, in 2007, two of its five authors were charged with fraud in connection with another cancer scam [11], which may mean that their 2003 data are not trustworthy.

Dubious Theories

Duffield’s mechanism list mixes a few truths with a lot of speculation to reach unjustified conclusions. Item #7, for example, states:

More insulin receptors on tumor cells increase drug uptake. Proposed. Uncontrolled proliferation of cancer cells is stimulated by a number of growth factors, including insulin (which stimulates energy uptake) and insulin-like growth factors (IGF) I and II (which stimulate cell division and growth). There are many more receptors for these hormones on the cell membranes of cancer cells than there are in normal cells. And some cancer cells actually secrete these hormones themselves, resulting in still faster growth. More insulin receptors means more insulin effect, so more drug will enter cancer cells due to the various mechanisms already outlined. This allows the drug to be given in a smaller dose, far less toxic to normal cells, while building up lethally toxic concentrations in cancer cells. Thus the growth mechanism of the cancer cell is used against it in IPT.


  • There is no such thing as a “cancer cell.” There are many types of cancer, and even within each “type,” cells can be very close to normal in look and behavior, or, at the opposite end of the spectrum, can be embryonic and undifferentiated. Even within a single tumor mass, there can be groups of different types of cells. All cancers involve uncontrolled growth, but one cannot legitimately characterize “cancer cells” as being identical in look, behavior, biochemistry, growth control, or any other feature.
  • Cell proliferation is stimulated by a number of growth factors, but this is not unique to “cancer cells.” Moreover, growth factors alone don’t cause uncontrolled proliferation. It is the presence and activity of certain genes and the lack of others that causes loss of growth control. In some settings IGF may stimulate growth of certain cells, but there is no particular relationship between IGF and cancer cells. Ira Goldfine’s group at UCLA has studied breast cancer cells and found that tumor cells with a normal amount of insulin receptors may be more similar to normal cells and more subject to normal controls on cell growth, and therefore less likely to grow back aggressively [12,13].
  • Hormone-secreting cancers (insulinomas) are very rare, and their secretion of insulin is irrelevant to their own growth. The more insulin that is secreted, the more “normal” they are. More insulin receptors does not automatically mean there is more insulin effect—the receptors have to work, and the insulin levels must be adequate.
  • There is no published evidence that insulin causes more drug to enter the cancer cells or that giving insulin enables chemotherapy drugs to build up within these cells while sparing normal cells.
Dubious Device

The IPT.org Web site states that during the 1950s and 1960s, Dr. Garcia and his son developed a device that could detect cancer and other diseases [14]. Called the “OncoDiagnosticator,” it consisted of a glass container that held a neutral solution into which two copper wires connected to a 32-volt power source are placed. The site states that the device was “extremely simple” and that “any high school student could make one for a science project.” Testing was conducted by placing a few milliliters of a patient’s serum (the clear fluid that remains after cells and clot are removed from a blood sample) into the solution and seeing what happens after two hours. According to the story:

The Drs. Perez Garcia found that the serum would often change to a violet color, readily visible when the serum was poured into a test tube at the end of the reaction. Based on their experience, they believed that absence of violet would mean absence of cancer, pale violet would mean susceptibility to cancer, darker violet would indicate early-stage still-hidden cancer, and very dark violet would indicate the presence of later-stage cancer discoverable by standard methods. Later work found other colors, again seeming to correlate with the type and severity of disease.

Although for them the color was the primary indicator, they also found that the pH of the electrolyte solution in the beaker would change depending on the patient’s condition. In healthy people the pH would be below 8.5. And in cancer patients the pH would be higher: 8.5-9.5 or more in males, and 9.5 to 10.5 in females. They also found that the temperature of the electrolyte solution would become higher in cancer patients than in normal people, and would be higher in female cancer patients than in male cancer patients. I assume that higher temperature means higher current flow, and indeed the doctors also measured current (milliamps). . . .

Dr. Perez Garcia y Bellon 2 told me that the color, pH, and temperature would move closer to normal as a patient underwent weeks of IPT treatments. So apparently their method could be used to monitor the progress of a patient’s condition [14].

If these claims were valid, this would have been one of the greatest medical discoveries of all time. Unfortunately, there isn’t the slightest theoretical reason or scientific evidence that the device works as claimed.

Regulatory Actions

At least three IPT providers have been severely disciplined by their state medical boards:

  • In 2007, Russell Hunt, M.D., who operated the Preventive Medicine and Wellness Clinic in Old Hickory, Tennessee, signed an agreed order under which he surrendered his license and was assessed $10,000 in civil penalties, plus costs. These penalties were applied because the Tennessee Board of Medical Examiners found him guilty of (a) unprofessional, dishonorable or unethical conduct; (b) making false statements or representations, being guilty of fraud or deceit in obtaining admission to practice, or being guilty of fraud or deceit in the practice of medicine; and (c) conviction of a felony. The unprofessional conduct included treating a patient with chelation therapy, intravenous hydrogen peroxide, and insulin potentiation therapy. His criminal conviction was for conspiring to submit false information to Medicare which paid approximately $92,000 for screening tests that were not medically necessary, were not performed, and/or were miscoded [15].
  • In 2012, the Medical Board of California revoked the medical license of Les Breitman, M.D., who operated the Alternative Cancer Treatment Center of Southern California in Oceanside, California. The clinic Web site stated that he specialized in “IPT Treatment for cancer and natural bio-identical hormone replacement and optimization for women and men.” The board concluded that Breitman had negligently treated a cancer patient and that his Web site had generally misrepresented the benefits and underplayed the risks of IPT treatment [16].
  • In 2012, Juergen Winkler, M.D., who operates Quantum Functional Medicine in Carlsbad, California,was placed on probation for three years and ordered to enroll in an ethics course and a clinical evaluation and training program. He was also prohibited from making or disseminating false or misleading statements about IPT. The accusation stated that Winkler had described IPT as a way to administer standard chemotherapeutic drugs at much lower doses so that patients do not suffer severe side effects. Howeverm, the board concluded that the drugs and dosages Winkler had administered to five cancer patients were inappropriate [17,18].
The Bottom Line

Although IPT’s proponents have been treating patients for decades, they have no tested theory and have produced at most only one properly designed clinical study of one cancer. If you would like to bet your money and your life on their general impressions, they’ll be happy to do business. However, the lack of evidence should serve as a powerful warning to stay away.

  1. Nationally recognized innovative cancer care physician now serving Chicagoland area. Press release, July 14, 2000.
  2. Local physician to present findings on innovative cancer treatment to the Cancer Advisory Panel at the National Institutes of health. Contemporary Medicine Web site, accessed Oct 12, 2003.
  3. Therapy costs. Integrated Medical Specialists Web site, accessed Oct 12, 2003.
  4. Dr. Ayre. Contemporary Medicine Web site, accessed Oct 12, 2003.
  5. Minutes of the Third Meeting of the Cancer Advisory Panel for Complementary and Alternative Medicine (CAPCAM), Sept 18, 2000.
  6. Insulin potentiation therapy. BlueCross of California medical policy #DRUG00034, Feb 5, 2007.
  7. Duffield C. My IPT story. (A 5-part series of articles.) IPTQ.org Web site, accessed Oct 13, 2003.
  8. Duffield C. How IPT works. IPTQ.org Web site, accessed Oct 12, 2003.
  9. Duffield C. Cancer and IPT. IPTQ.org Web site, accessed Oct 13, 2003.
  10. Insulin-induced enhancement of antitumoral response to methotrexate in breast cancer patients. Cancer Chemotherapy and Pharmacology 53:220-224, 2004.
  11. Barrett S. Seven indicted for PharmaBlood cancer fraud. Casewatch, March 9, 2007.
  12. Papa V and others. Insulin-like growth factor-I receptors are overexpressed and predict a low risk in human breast cancer. Cancer Research 53:3736-3740, 1993.
  13. Mathieu MC and others. Insulin receptor expression and clinical outcome in node-negative breast cancer. Proceedings of the Association of American Physicians 109:565-571, 1997.
  14. Onco. IPTQ.org Web site, accessed Oct 17, 2003.
  15. Barrett S. Russell Hunt surrenders medical license, Casewatch, Nov 4, 2007.
  16. Barrett S. Les Breitman loses medical license. Casewatch, Aug 31, 2013.
  17. Accusation. In the Matter of the Accusation against Juergen G. Winkler, M.D. Medical Board of California Case No. 10-02009-200762, Filed June 9, 2011.
  18. Decision and order. In the Matter of the Accusation against Juergen G. Winkler, M.D. Medical Board of California Case No. 10-02009-200762, June 13, 2012.

Dr. Baratz is president and medical director of South Shore Health Center in Braintree, Massachusetts, where he practices general and occupational medicine.. He has extensive training and practical experience in internal medicine, emergency medicine, oral medicine, dentistry, material science, and research methodology. He also serves as a medical and dental consultant to many state licensing boards, federal agencies, insurance companies, and the legal profession.

This article was revised on August 31, 2013.