[The following is a first person account of how one person "cured" herself of metastatic breast cancer using a safe, inexpensive, side-effect free, over-the-counter substance. The writer is not an oncologist and is not giving cancer treatment advice to any individual. Nor do we sell the treatment or have any relationship with the makers of the product described below. However, if I ever were to get cancer this approach outlined here will be my first line of treatment! P. S. if I hadn't witnessed the following first-hand I would probably be skeptical too. However, in an attempt to "pay it forward" to the anonymous comment poster who informed me of his success with fenbendazole on his prostate cancer, I present the following account of my courageous mother-in-law's battle with cancer and how she defeated it. ]

In Nov 2021 my 83-yr-old mother-in-law went into the hospital for a bowel obstruction. During the course of investigating that issue it was discovered, by PET scan and blood tests, that she had metastatic breast cancer (MBC) tumors in her lungs, liver, kidneys, spleen, pancreas, gall bladder and bones (spine, ribs, pelvis). She had estrogen-dependent breast cancer 11 years earlier and was treated and declared cancer-free shortly thereafter. Furthermore, in 2019, she received an “all-clear” report from Moffatt Cancer Center on followup. Back to present day, the bowel obstruction resolved without surgery and she was given her options regarding treating her MBC tumors. The doctors told her that they could not cure the cancer but they could prolong her life for a short period of time. At one point before her release her condition deteriorated such that Last Rites were administered. She rallied somewhat and requested to leave the hospital. She decided against all traditional treatments (chemo/radiation) and was sent home to hospice care.

She needed a walker, was weak and required in-home care.

We had come across a reference to an experimental treatment called fenbendazole that had a number of amazing anecdotal reports that could be summarized as “it worked for me!”  An analysis of some of the supporting papers describing the mechanisms through which fenbendalzole worked to kill cancer cells was simple and straightforward. Fenbendazole is a veterinary anti-parasite medication primarily used to treat worm infestations in animals. Fenbendazole selectively disrupts the microtubule transport system within the parasite cell starving it of glucose and killing it. Petrie dish studies of FenBen indicated that it worked within 12 hours, killing human lung cancer cells without harming healthy cells. Not only did FenBen appear to eradicate the cancer cells, it was also selective, killing only cancer cells. This lack of nonspecific toxicity is one reason why FenBen appears to have no adverse side effects. My mother-in-law had none.

Because she had intestinal issues and we were concerned about nausea before my mother-in-law took FenBen, I took it for 3 days to “see what happens”. Nothing. Then my wife, 50% genetic match to her mother took it. Nothing, no noticeable adverse effects. So we were somewhat confident that she would not be sickened by FenBen, which was correct.

Below is the original email that was sent to my wife’s siblings for them to consider before suggesting FenBen to their mother (you may find this email useful if you encounter a similar situation in your family, please feel free to copy it).


Fenbendazole (FenBen)
Antiparasitic used to treat roundworms, pinworms, etc. in animals and humans since 1961.
Accidental Discovery – gliobastoma study in which cancer cells implanted into the brains of mice encountered failure to grow tumors in those mice that were pretreated with FenBen (to deworm the mice) as normal course of veterinary care. So the tumors that were supposed to grow as part of the experiment did not, once they figured out why, the discovery was made.
FenBen is extremely safe, always administered orally, no side effects, inexpensive and easy to obtain.
Case reports of effectiveness.
Cancers of the lung, kidney, liver, breast, prostate, melanoma, bone, ovary, colon and brain (glial cells) all seem to be favorably affected. There have even been reports of effectiveness on pancreatic cancer. Most of the cases involved spread to other organs (metastatic). Why this is important…suggests there is a common vulnerability in the cancer cell that is independent of where the tumor is located.
The case reports seem to have a common theme.
Patient goes through standard chemo and radiation treatment for their cancer and either the side effects are intolerable or the cancer persists despite the treatment. The patient learns out about FenBen and they have nothing to lose in trying it. Subsequent diagnostic imaging finds reduced or eliminated tumor activity.
How FenBen works.
Appears to have multiple potential mechanisms to selectively kill cancer cells.
First is disruption of the microtubule system that the cancer cell needs to survive and replicate.
Second is disruption of glucose utilization blocking the energy supply to the cancer cell.
Third is upregulation (increase) of P53 tumor suppressor genes that help kill cancer cells.
Finally, it looks like FenBen also blocks the formation of new blood vessels to the tumor, this will starve and kill it.
Each one of these mechanisms has been targeted individually by traditional cancer drugs but don’t seem to be as effective as FenBen.
What is really amazing about FenBen is that there appears to be a highly selective effect on cancer cells only, healthy cells are not affected or harmed in any measurable way. This is why there are no reported side effects like hair loss, nausea, etc.
There are some conflicting reports regarding combining FenBen with Vitamin E and Curcumin to enhance effectiveness. We can cross that bridge later.
Is FenBen effective by itself…with no traditional chemo or radiation cancer treatment? There are case reports where people have tried FenBen first and that was all that was needed to put their cancer into remission.
How long does it take to work, if it does? Some of the experiments in petrie dishes show that within 12 hours of treatment glucose utilization is affected as well as microtubule function of human cancer cells (lung). The case reports are less specific because they rely on scheduled diagnostic scanning, which is uncontrolled and variable. The consensus seems to be 4 weeks to 3 months is a reasonable time frame to expect results. However it is encouraging that FenBen has an almost immediate effect in vitro, 12 hours, which is consistent with its antiparasitic action (the course of treatment to kill roundworms is 3 days).
Theory. What is happening here? Nature tends to conserve form and function for efficiency, and it looks like parasites and cancer cells are similar in the following respect: they are both foreign to the host and contain similar structural weaknesses. The microtubule system in parasites and cancer cells is somehow vulnerable to FenBen whereas normal healthy cells are not. Just like FenBen selectively kills the invading (non-self) parasitic worm cells it also selectively kills the invading (non-self) cancer cells while ignoring the healthy cells (self) with their different microtubule structure. No one knows what those differences are, but fortunately there are differences that make FenBen work.
What to do.
Week 1:             3 cons. days FenBen, 4 days off. See how it’s tolerated.
Week 2 – 8:       Daily FenBen
Week 9:             Diagnostic testing


My mother-in-law did not take any other agent suggested by some others to be additive with FenBen (Vitamin E, Curcumin, CBD oil), other than vitamin D. So, at least in her case, FenBen alone was enough.

Observations: As stated above, she was in dire trouble when released from the hospital. Her voice was weak and her survival was day-to-day. She started taking FenBen, 222 mg once per day sprinkled on a few tablespoons of yogurt on November 22, 2021. We were concerned about absorption due to her intestinal issues and overall strength. Fortunately, she appeared to turn the corner within two weeks, in that, her strength, appetite, and appearance all improved, markedly. Within four weeks she was strong and confident enough to release hospice. She could walk on her own and was gaining weight.

On Dec 28, 2021, she had recovered enough to make a visit to an oncologist meaningful. She still refused traditional chemo and radiation but agreed to injections of fulvestrant (an estrogen receptor blocker). She continued to take FenBen every day (no specific time period during day).

On Jan 10, 2022 she received targeted radiation of two tumors in her spine that were causing pain. The tumors rapidly disappeared, relieving the pain. There is a literature indicating the FenBen potentiates traditional chemo and radiation therapies, as happened in her case. Radiologist remarked the radiation worked extremely fast in her case. Again, anecdotal but relevant.

Near the end of Jan 2022 the consensus of the family was that she was back to her prior self with respect to attitude, appearance and activity. She got back on her bike in early February, quite a change from needing a walker in November.

Blood Tumor Marker CA 27.29

The figure below plots the change in CA 27.29, a blood tumor marker that is specific to MBC, over time. A reading of over 100 indicates active MBC, while a reading below 38 is normal. When she left the hospital, her reading was 316 on Nov 22, 2021. There was no measurement until two months later as she was in hospice care and further measurements were deemed irrelevant at that point. On Jan 20, 2022, CA 27.29 dropped to 131 and continues to drop into the normal range (CA 27.29 measures can lag the elimination of the cancer by up to 3-4 months). On April 20 she received her second PET scan (first one was in hospital), which confirmed the absence of any metabolic activity indicative of cancer. These PET scan results corroborated the CA 27.29 data, all of which fit with the observational impression on her appearance and overall well-being described above. So, we could see that she was getting better, the PET scan and blood tumor markers confirmed what was visually apparent. Again, NO SIDE EFFECTS!*

On May 4, 2022 her CA27.29 reading dropped to 47. PET scans detected no abnormal metabolic activity, which means no cancer. On July 20, 2022 her CA27.29 dropped to 37, which is normal. PET scans continued to detect no abnormal activity. She feels great, looks great and is happy.
Note: Fulvestrant, an estrogen receptor blocker, limits the further growth of estrogen-dependent tumors but typically does not kill them. Fulvestrant typically does not affect blood tumor marker readings.


Going Forward

Recently we celebrated her 84th birthday and it was refreshing to get the family together under happy circumstances versus the alternative.  One question going forward is should she continue to take FenBen as a preventative measure? Probably, because she is high risk. Does she need it everyday? Don’t know.
*Update July 28, 2022. She stopped taking FenBen after 8 months of daily use. Her cancer is gone. Also, coincident with her taking fulvestrant injections her blood work showed elevated ALT and ALK readings indicative of liver malfunction. We don't know if the fluvestrant, FenBen or an interaction between the two is related to her liver numbers. Stopping FenBen, after it has served its purpose, seems to be the wise action to take. She has no symptoms or discomfort from the ALK and AST readings.
UPDATE: Aug 20, 2022. ALK and AST readings are normal. So whatever changes occurred in her liver panels was temporary.

What Fenbendazole to use and where to get it?

FenBen is available without a prescription in pet stores, Walmart and Amazon. It is inexpensive (as of May 12, 2022 PanacurC was $7.99 for 3 packets of 222 mg; the 25g bulk bottle was $48 equating to a 43 cents per day dose over the 112 days the 25 g will cover. We've used two forms. First was the individual packets with the dog on the label. Then we used the bulk powder, which includes a simple-to-use 222 mg measuring spoon. Both seem equally effective in our hands.



Williams, David (2019) A cure for cancer hidden in plain sight https://fenbendazole.s3.amazonaws.com/A-Cure-for-Cancer-Hidden-in-Plain-Sight-July-2019-Dr-David-Williams.pdf

Chiang RS, Syed AB, Wright JL, Montgomery B, Srinivas S (2021) Fenbendazole Enhancing Anti-Tumor Effect: A Case Series. Clin Oncol Case Rep 4:2 https://www.scitechnol.com/abstract/fenbendazole-enhancing-antitumor-effect-a-case-series-14307.html

Mukhopadhyay T, Sasaki J, Ramesh R, Roth JA. Mebendazole elicits a potent antitumor effect on human cancer cell lines both in vitro and in vivo. Clin Cancer Res. 2002 Sep;8(9):2963-9. PMID: 12231542. https://pubmed.ncbi.nlm.nih.gov/12231542/

Dogra, N., Kumar, A. & Mukhopadhyay, T. Fenbendazole acts as a moderate microtubule destabilizing agent and causes cancer cell death by modulating multiple cellular pathways. Sci Rep 8, 11926 (2018). https://www.nature.com/articles/s41598-018-30158-6

Guerini, A. E., et al (2019). Mebendazole as a Candidate for Drug Repurposing in Oncology: An Extensive Review of Current Literature. Cancers, 11(9), 1284. https://doi.org/10.3390/cancers11091284

Note: Mebendazole is the much more expensive, prescription-based fenbendazole. They are chemically identical and dollar different.


We will continue to update her progress here. If you have any questions please send them along. I will tell you what I know and, perhaps more importantly, what I don't about fenbendalzole and cancer.

What types of cancer is FenBen been shown to be effective on? Solid tumor cancers. Blood-based cancers initially did not seem to be affected but recent data suggest FenBen may be useful in the leukemias and myleomas...do you own research.