Written by Luc Geeraert and the CAM-Cancer Consortium.
Updated June 29, 2017

Insulin potentiation therapy

Does it work?

IPT inventor Perez and his successors claimed that several cancer patients were successfully treated with IPT 1,3, though case reports or clinical trials to substantiate these claims have never been published in peer-reviewed journals.

More recently, two small clinical studies and four cases have been published in peer-reviewed journals.

Clinical trials

In a small uncontrolled study 4, 16 patients with castration-resistant tumours were treated with insulin (0.4 units per kg body weight at 5-day intervals) in combination with goserelin depot (3.6 mg) and low-dose chemotherapy, i.e., eight patients with: cyclophosphamide (0.10–0.15 g/m2) + epirubicin (3 mg/m2) + vinblastine (0.5 mg/m2), and eight patients with docetaxel (3.6 mg/m2). Overall prostate-specific antigen (PSA) results after the sixth course of IPT showed partial effect in eight patients, stabilization in four patients, and disease progression in four patients; the median survival for all treated patients was 11.7 months. During the treatment no significant side effects were observed, and no lethal cases occurred.

In a small prospective, controlled, randomized clinical trial 5, IPT was tested in 30 women suffering from metastatic breast cancer resistant to 5-fluorouracil + doxorubicin + cyclophosphamide and to hormone therapy with measurable lesions 4. Patients were divided in three groups of ten: a group receiving only the anticancer drug methotrexate (2.5 mg/m2 every other day), a group receiving only insulin (0.3 units per kg body weight every other day), and a group receiving a combination of both. Drugs were given in two 3-week courses with a 1-week interval in-between. After 8 weeks, the sizes of the target tumours were measured and compared to the respective sizes before treatment. Progressive disease was less frequently observed in the group treated with the combination of methotrexate and insulin, and in this group the median increase in tumour size was found to be significantly lower than in the groups where drugs were used separately. Quality of life, patient survival, or lasting effects were not evaluated.

Case studies

Three cases of IPT in patients with advanced metastatic cancer and failure of preceding standard conventional treatment have been described: two women with breast cancer, and one man with prostate cancer 13. The initial 4 to 6 IPT courses (insulin + patient-specific chemotherapy) were repeated weekly after which a maintenance schedule at several-week intervals was started. The treatment was well tolerated. Laboratory examinations showed no significant toxicity. Remission was achieved for 15 months (after which the patient was lost to follow up), and 21 and 8 months (publication time of results).

In another case study, a woman with breast cancer was treated with IPT 14. Treatment (insulin + chemotherapy) was repeated twice-weekly for 3 weeks, and then weekly for 5 weeks. After 8 weeks, the breast mass was no longer palpable, and no evidence of tumour was found on a xeromammogram at 3 months.

Pre-clinical trials

Tumour-bearing rats were found to have a significantly more reduced tumour size after treatment with doxorubicin (one single dose) and insulin (once-daily, starting 1 day after doxorubicin administration) than after being treated with doxorubicin alone 15. Insulin also led to a marked improvement in food intake and host weight.

In several human cancer cell lines, insulin enhanced the cytotoxic effect of chemotherapeutics 16-19. Testing a broad range of human tumours 20, insulin increased significantly the colony formation in about half of the tested tumour cells, but only little difference in the sensitivity to cytotoxic agents was observed.


Luc Geeraert, CAM-Cancer Consortium. Insulin potentiation therapy [online document]. http://www.cam-cancer.org/The-Summaries/Dietary-approaches/Insulin-potentiation-therapy. June 29, 2017.

Document history

Assessed as up to date in June 2017 by Barbara Wider.

Assessed as up to date in April 2016 by Barbara Wider.

Most recent update and revision in January 2013 by Luc Geeraert.

Summary first published in August 2011, authored by Luc Geeraert.


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